Dataset from RNAseq analysis of differential gene expression among developmental stages of two non-marine ostracodes.

We contribute transcriptomic data for two species of Ostracoda, an early-diverged group of small-sized pancrustaceans. Data include new reference transcriptomes for two asexual non-marine species (Dolerocypris sinensis and Heterocypris aff. salina), as well as single-specimen transcriptomic data that served to analyse gene expression across four developmental stages in D. sinensis. Data are evaluated by computing gene expression profiles of the different developmental stages which consistently placed eggs and small larvae (at the stage of instar A-8) similar to each other, and apart from adults which were distinct from all other developmental stages but closest to large larvae (instar A-4). We further evaluated the transcriptomic data with two newly sequenced low-coverage genomes of the target species. The new data thus document the feasibility of obtaining reliable transcriptomic data from single specimens - even eggs - of these small metazoans.

LAG-3- and CXCR5-expressing CD4 T cells display progenitor-like properties during chronic visceral leishmaniasis.

Maintenance of CD4 T cells during chronic infections is vital for limiting pathogen burden and disease recrudescence. Although inhibitory receptor expression by CD4 T cells is commonly associated with immune suppression and exhaustion, such cell-intrinsic mechanisms that control activation are also associated with cell survival. Using a mouse model of visceral leishmaniasis (VL), we discovered a subset of lymphocyte activation gene 3 (LAG-3)-expressing CD4 T cells that co-express CXCR5. Although LAG3+CXCR5+ CD4 T cells are present in naive mice, they expand during VL. These cells express gene signatures associated with self-renewal capacity, suggesting progenitor-like properties. When transferred into Rag1-/- mice, these LAG3+CXCR5+ CD4 T cells differentiated into multiple effector types upon Leishmania donovani infection. The transcriptional repressor B cell lymphoma-6 was partially required for their maintenance. Altogether, we propose that the LAG3+CXCR5+ CD4 T cell subset could play a role in maintaining CD4 T cell responses during persistent infections.

Leishmania donovani Exploits Tunneling Nanotubes for Dissemination and Propagation of B Cell Activation.

Polyclonal B cell activation and the resulting hypergammaglobulinemia are a detrimental consequence of visceral leishmaniasis (VL); however, the mechanisms underlying this excessive production of nonprotective antibodies are still poorly understood. Here, we show that a causative agent of VL, Leishmania donovani, induces CD21-dependent formation of tunneling nanotubule (TNT)-like protrusions in B cells. These intercellular connections are used by the parasite to disseminate among cells and propagate B cell activation, and close contact both among the cells and between B cells and parasites is required to achieve this activation. Direct contact between cells and parasites is also observed in vivo, as L. donovani can be detected in the splenic B cell area as early as 14 days postinfection. Interestingly, Leishmania parasites can also glide from macrophages to B cells via TNT-like protrusions. Taken together, our results suggest that, during in vivo infection, B cells may acquire L. donovani from macrophages via TNT-like protrusions, and these connections are subsequently exploited by the parasite to disseminate among B cells, thus propagating B cell activation and ultimately leading to polyclonal B cell activation. IMPORTANCE Leishmania donovani is a causative agent of visceral leishmaniasis, a potentially lethal disease characterized by strong B cell activation and the subsequent excessive production of nonprotective antibodies, which are known to worsen the disease. How Leishmania activates B cells is still unknown, particularly because this parasite mostly resides inside macrophages and would not have access to B cells during infection. In this study, we describe for the first time how the protozoan parasite Leishmania donovani induces and exploits the formation of protrusions that connect B lymphocytes with each other or with macrophages and glides on these structures from one cell to another. In this way, B cells can acquire Leishmania from macrophages and become activated upon contact with the parasites. This activation will then lead to antibody production. These findings provide an explanation for how the parasite may propagate B cell activation during infection.

The TLR7/IRF-5 axis sensitizes memory CD4+ T cells to Fas-mediated apoptosis during HIV-1 infection.

HIV-1 infection is characterized by inflammation and a progressive decline in CD4+ T cell count. Despite treatment with antiretroviral therapy (ART), the majority of people living with HIV (PLWH) maintain residual levels of inflammation, a low degree of immune activation, and higher sensitivity to cell death in their memory CD4+ T cell compartment. To date, the mechanisms responsible for this high sensitivity remain elusive. We have identified the transcription factor IRF-5 to be involved in impairing the maintenance of murine CD4+ T cells during chronic infection. Here, we investigate whether IRF-5 also contributes to memory CD4+ T cell loss during HIV-1 infection. We show that TLR7 and IRF-5 were upregulated in memory CD4+ T cells from PLWH, when compared with naturally protected elite controllers and HIVfree participants. TLR7 was upstream of IRF-5, promoting Caspase 8 expression in CD4+ T cells from ART HIV-1+ but not from HIVfree donors. Interestingly, the TLR7/IRF-5 axis acted synergistically with the Fas/FasL pathway, suggesting that TLR7 and IRF-5 expression in ART HIV-1+ memory CD4+ T cells represents an imprint that predisposes cells to Fas-mediated apoptosis. This predisposition could be blocked using IRF-5 inhibitory peptides, suggesting IRF-5 blockade as a possible therapy to prevent memory CD4+ T cell loss in PLWH.

Mercury Pollution History in Tropical and Subtropical American Lakes: Multiple Impacts and the Possible Relationship with Climate Change.

Sediment cores obtained from 11 tropical and subtropical American lakes revealed that local human activities significantly increased mercury (Hg) inputs and pollution levels. Remote lakes also have been contaminated by anthropogenic Hg through atmospheric depositions. Long-term sediment-core profiles revealed an approximately 3-fold increase in Hg fluxes to sediments from c. 1850 to 2000. Generalized additive models indicate that c. 3-fold increases in Hg fluxes also occurred since 2000 in the remote sites, while Hg emissions from anthropogenic sources have remained relatively stable. The tropical and subtropical Americas are vulnerable to extreme weather events. Air temperatures in this region have shown a marked increase since the 1990s, and extreme weather events arising from climate change have increased. When comparing Hg fluxes to recent (1950-2016) climatic changes, results show marked increases in Hg fluxes to sediments during dry periods. The Standardized Precipitation-Evapotranspiration Index (SPEI) time series indicate a tendency toward more extreme drier conditions across the study region since the mid-1990s, suggesting that instabilities in catchment surfaces caused by climate change are responsible for the elevated Hg flux rates. Drier conditions since c. 2000 appear to be promoting Hg fluxes from catchments to lakes, a process that will likely be exacerbated under future climate-change scenarios.

Evaluation of Lake Sediment Thickness from Water-Borne Electrical Resistivity Tomography Data.

Lakes are integrators of past climate and ecological change. This information is stored in the sediment record at the lake bottom, and to make it available for paleoclimate research, potential target sites with undisturbed and continuous sediment sequences need to be identified. Different geophysical methods are suitable to identify, explore, and characterize sediment layers prior to sediment core recovery. Due to the high resolution, reflection seismic methods have become standard for this purpose. However, seismic measurements cannot always provide a comprehensive image of lake-bottom sediments, e.g., due to lacking seismic contrasts between geological units or high attenuation of seismic waves. Here, we developed and tested a complementary method based on water-borne electrical-resistivity tomography (ERT) measurements. Our setup consisted of 13 floating electrodes (at 5 m spacing) used to collect ERT data with a dipole-dipole configuration. We used a 1D inversion to adjust a layered-earth model, which facilitates the implementation of constraints on water depth, water resistivity, and sediment resistivity as a priori information. The first two parameters were readily obtained from the echo-sounder and conductivity-probe measurements. The resistivity of sediment samples can also be determined in the laboratory. We applied this approach to process ERT data collected on a lake in southern Mexico. The direct comparison of ERT data with reflection seismic data collected with a sub-bottom profiler (SBP) showed that we can significantly improve the sediment-thickness estimates compared to unconstrained 2D inversions. Down to water depths of 20 m, our sediment thickness estimates were close to the sediment thickness derived from collocated SBP seismograms. Our approach represents an implementation of ERT measurements on lakes and complements the standard lake-bottom exploration by reflection seismic methods.

Holocene life and microbiome profiling in ancient tropical Lake Chalco, Mexico.

Metagenomic and traditional paleolimnological approaches are suitable to infer past biological and environmental changes, however, they are often applied independently, especially in tropical regions. We combined both approaches to investigate Holocene Prokaryote and Eukaryote diversity and microbial metabolic pathways in ancient Lake Chalco, Mexico. Here, we report on diversity among a large number of lineages (36,722 OTUs) and functional diversity (27,636,243 non-clustered predicted proteins, and 6,144 annotated protein-family genes). The most abundant domain is Bacteria (81%), followed by Archaea (15%) and Eukarya (3%). We also determined the diversity of protein families and their relationship to metabolic pathways. The early Holocene (> 11,000 cal years BP) lake was characterized by cool, freshwater conditions, which later became warmer and hyposaline (11,000-6,000 cal years BP). We found high abundances of cyanobacteria, and fungi groups associated with mature forests in these sediments. Bacteria and Archaea include mainly anaerobes and extremophiles that are involved in the sulfur, nitrogen, and carbon cycles. We found evidence for early human impacts, including landscape modifications and lake eutrophication, which began ~ 6,000 cal years BP. Subsaline, temperate conditions were inferred for the past 5,000 years. Finally, we found nitrogen-fixing bacteria and protein-family genes that are linked to contaminated environments, as well as several fungal pathogens of crops in near-surface sediments.

Plasma microparticles from patients with systemic lupus erythematosus modulate the content of miRNAs in U937 cells.

In systemic lupus erythematosus (SLE), the clearance of apoptotic cells and microparticles (MPs) is reduced. Some MPs contain molecules that can modulate immune responses. This study aimed to evaluate the presence of miR-126 and miR-146a in plasma MPs of patients with SLE (SLE MPs) and analyse the ability of MPs to modulate some events in the promonocytic U937 cell line. Circulating MPs were isolated from plasma samples of healthy controls (HCs), patients with SLE and other autoimmune diseases (OAD). MPs were analysed for size and cell origin by flow cytometry and content of miR-126 and miR-146a by RT-qPCR. MPs were then added to U937 cell cultures to evaluate changes in cell phenotype, cytokine expression, content of miR-126 and miR-146a, and levels of IRF5. Patients with active SLE (aSLE) showed an increase in concentration of plasma MPs that positively correlated with the SLEDAI (SLE Disease Activity Index) score. CD14+ MPs were significantly more abundant in patients with SLE than HCs. SLE MPs contained decreased levels of miR-146a, but the miR-126 content in aSLE MPs was increased. The miR-126 content in SLE MPs correlated positively with the SLEDAI score. The treatment of U937 cells with MPs from HCs and patients induced reduced expression of HLA-DR, CD18 and CD119, increased frequency of IL-6+ and TNF-α+ cells, accumulation of IL-8 in culture supernatants, increased miR-126 levels and decreased miR-146a content, but no change in the expression of IRF5. These findings suggest that plasma MPs, especially SLE MPs, could modulate some biological events in U937 cells.

Tropical freshwater ostracodes as environmental indicators across an altitude gradient in Guatemala and Mexico

Detailed knowledge of species ecological preferences and robust taxonomy of paleobioindicators are prerequisites for accurate paleoclimate and paleoenvironmental studies. This study aims to expand the knowledge of modern, Neotropical freshwater ostracode fauna, across an altitudinal gradient from the karst lakes in the lowlands of El Petén, Guatemala (100-500 m.a.s.l.), to the mid-elevation lakes of the Lacandón forest (500-1 000 m.a.s.l.), to the higher-altitude lakes of Montebello, Chiapas, Mexico (1 000-1 500 m.a.s.l.). Eighteen ostracode species were identified in 24 lakes. Ostracodes were absent in Lakes Amarillo and Lacandón (mid-altitude), and San Diego (lowlands); probably explained by a structural difference of habitats and species interactions. Statistical analysis indicated that the most abundant species, Cypridopsis vidua (O.F. Müller, 1776), Cytheridella ilosvayi (Daday, 1905), Pseudocandona antillana (Broodbakker, 1983), and Darwinula stevensoni (Brady & Robertson, 1870) have a continuous distribution along the entire altitudinal gradient. Some species display more restricted distributions, determined by temperature, precipitation and conductivity. For example, Eucypris sp. is restricted to the lowlands, Vestalenula sp. and Cypria sp. were found only at middle elevations. Species diversity is slightly greater in lakes at middle altitudes (Haverage = 1.09) than in water bodies in the lowlands (Haverage = 0.94) and in cooler lakes in the highlands (Haverage = 0.94), suggesting that mid-elevation lakes have a high potential for harboring microrefugia. Locally weighted scatterplot smoothing (LOESS regressions) provided ecological preference information for the four most frequent and widely distributed species, with respect to temperature, conductivity, bicarbonate (HCO3 -) concentration, precipitation, and pH. Darwinula stevensoni suggest an association more to cooler temperatures and lower conductivities proving its high tolerance range. Cypridopsis vidua is associated with warm and low-rainfall environments, such as recorded in the lowlands of Guatemala, and can be used as a paleobioindicator of vegetated littoral zones, because we found it always associated to this section of lakes. Cytheridella ilosvayi show preferences for warm and humid conditions, whereas P. antillana prefer colder and humid environments. Such quantitative-ecological information will improve ostracode-based paleoenvironmental reconstructions in Southern Mexico and Northern Guatemala. In addition, our approach serves as a model for future paleoecological studies that employ other aquatic bioindicators, such as testate amoebae, cladocerans, and chironomids.

Los ostrácodos son microcrustáceos acuáticos, que poseen un caparazón bivalvo de carbonato de calcio que se puede preservar en los sedimentos de los ambientes lacustres. Debido a su alta sensibilidad a cambios ambientales y su alta potencialidad de fosilización, los ostrácodos son una herramienta útil para el estudio paleoclimático y paleoambiental, abarcando una temporalidad de décadas hasta millones de años. El conocimiento ecológico de las especies, así como su taxonomía son prerrequisitos para estos estudios. Sin embargo, esta información es aún escasa en diferentes regiones del mundo, incluyendo los Neotrópicos. Hasta el momento, se han realizado únicamente estudios en los lagos kársticos de las tierras bajas de la Península de Yucatán, en el norte del Neotrópico. Sin embargo, los lagos en altitudes medias y altas permanecen poco conocidos. El objetivo de este trabajo es aportar conocimiento de ostrácodos no-marinos neotropicales a lo largo de un gradiente altitudinal que va desde las tierras bajas de El Petén, Guatemala (100-500 m s.n.m.), incluyendo los lagos de tierras medias de la Selva Lacandona (500-1 000 m s.n.m.), hasta las tierras altas de Montebello, Chiapas, México (1 000-1 500 m s.n.m.). Dieciocho especies de ostrácodos se identificaron en 24 lagos, pero estuvieron ausentes en los lagos Amarillo y Lacandón (tierras medias) y San Diego (tierras bajas). La ausencia de ostrácodos podría explicarse por la falta de un muestreo estacional o por variables que no se consideraron en este estudio como sustrato, cobertura vegetal acuática e interacciones interespecíficas. Los análisis estadísticos indicaron que las especies más abundantes son: Cypridopsis vidua (O.F. Müller, 1776), Cytheridella ilosvayi (Daday, 1905), Pseudocandona antillana (Broodbakker, 1983) y Darwinula stevensoni (Brady & Robertson, 1870), con una distribución continua a lo largo del gradiente altitudinal. Algunas especies presentan una distribución más restringida, determinada por la temperatura, precipitación y conductividad. Por ejemplo, Eucypris sp. está restringida a las tierras bajas; mientras que Vestalenula sp. y Cypria sp. se encontraron únicamente en elevaciones medias. La diversidad de especies es ligeramente mayor en lagos cálidos a altitudes medias (Haverage = 1.09) que en las tierras bajas (Haverage = 0.94) y que en lagos de agua más fría en las tierras altas (Haverage = 0.94), sugiriendo que los lagos de tierras medias tienen un alto potencial para albergar micro-refugios. Las regresiones LOESS muestran las preferencias ecológicas de las cuatro especies más frecuentes y altamente distribuidas con respecto a la temperatura, conductividad, HCO3 -, precipitación y pH. Darwinula stevensoni se asocia a temperaturas frías y conductividades bajas, lo que evidencia su alto rango de tolerancia. Cypridopsis vidua se asocia con ambientes cálidos y de baja precipitación, como los registrados en las tierras bajas de Guatemala, y puede usarse como paleobioindicador de zonas de vegetación litoral. Cytheridella ilosvayi es un indicador de condiciones cálidas y húmedas, mientras que P. antillana de frías y húmedas. Esta información ecológica-cuantitativa se podrá utilizar como una herramienta para las reconstrucciones paleoambientales basadas en ostrácodos en el sur de México y norte de Guatemala. Además, este enfoque sirve como modelo para futuros estudios paleoecológicos que emplean otros bioindicadores acuáticos, como las amebas testadas, los cladóceros y los quironómidos.

Percepción de los pacientes acerca del cuidado de enfermería en una Clínica de Sincelejo Colombia / Patient ́s perception about nursing care clinic of Sincelejo Colombia

El propósito principal del estudio es determinar la percepción que tienen los pacientes acerca del cuidado brindado por el profesional de enfermería, con los factores de falta de compromiso, interacción familia/paciente, cortesía y relación. MÉTODO: Estudio descriptivo, transversal en el que participaron 152 pacientes, obtenidos mediante muestreo no probabilístico intencional o por conveniencia. La recolección de las características sociodemográficas de usuarios y profesionales de enfermería se apoya en un cuestionario con preguntas estructuradas. La información de percepción del paciente se recolecta mediante entrevistas utilizando el Instrumento "Cuidado de comportamiento profesional""forma A", validado por otra autora. RESULTADOS: Los hallazgos evidencian que el 80,26% de los pacientes respondieron nunca han percibido que el profesional de enfermería no realizara actividades tendientes al cuidado del paciente; el 28,95% percibe que algunas veces la enfermera(o) realiza actividades de relación con los pacientes y sus familiares; el 55.26% de los encuestados considera que casi siempre la enfermera(o) tiene una actitud cariñosa y auténtica hacia el paciente; el 53,29% aseguraron que casi siempre la enfermera(o) utiliza las herramientas para mantener una relación efectiva. CONCLUSIONES: Los pacientes, en su mayoría, perciben que el cuidado brindado por el profesional de enfermería es bueno. Sin embargo, hay una porción significativa que percibe que el servicio es regular en el aspecto de la interacción familia/paciente, específicamente en cuanto al conocimiento y respeto de las creencias religiosas. Hay que fortalecer esto para mejorar el acto de cuidado

The main purpose was to determine the patients' perception about the care provided by nursing professional, regarding issues related with lack of compromise factors, family/patient interaction, courtesy and respect. METHOD: A descriptive, transversal studythat included 152 patients, obtained by intentional or convenience non-probabilistic sampling. The recollection of socio-demographic characteristics of users and nursing professional is supported by a questionnaire with structured questions. The patients'perception information is collected through interviews using the Professional behavior care instrument "form A", validated by another author. RESULTS: The findings show that 80.26% of the patients responded they never perceived that the nursing professional did not perform activities favoring patient care; 28.95% perceive that sometimes the nurse performs activities to relate with the patients and their families; 55.26% of the respondents consider that the nurse almost always has a loving and authentic attitude towards the patient; 53.29% said that most of the time the nurse uses tools to maintain an effective relationship with them. CONCLUSIONS: Patients, generally, perceive that the care provided by the nursing professional is good; however, a significantportion emphasized that the service is regular on the family-patient interaction, specifically in terms of knowledge and respect of religious beliefs. This must be strengthened to improve care act.

Testate Amoebae (Amebozoa: Arcellinida) in Tropical Lakes of Central Mexico / Amebas testadas (Amebozoa, Arcellinida) en lagos tropicales del centro de México

AbstractTestate amoebae are common single-celled eukaryotic organisms in aquatic ecosystems. Despite their important role in these ecosystems, and their potential as bioindicators and paleoindicators, they remain poorly studied in Mexico. The major objectives of this study were to: 1) increase knowledge of testate amoebae in Mexico's tropical lakes, and 2) create a catalog of high-quality scanning electron micrographs that can be used for future ecological and paleoenvironmental studies. We collected surface-sediment samples from 29 lakes, located in the Transmexican Volcanic Belt, one at each lake during June and October 2011, and March 2013. Sediments were collected with an Ekman grab and preserved in anhydrous ethanol. Sub-samples were observed under a stereomicroscope and morphometric data for each species were recorded. Total diameter and aperture diameter were measured on circular tests. Irregularly shaped tests were measured for length and width of the aperture and for the size of the whole test. If a specimen possessed spines, the length of one randomly selected spine was measured. The best-preserved specimen of each taxon was photographed with an optical microscope and a scanning electron microscope (SEM). We found 41 taxa of testate amoebae belonging to the genera: Arcella, Argynnia, Centropyxis, Cucurbitella, Cyclopyxis, Cyphoderia, Difflugia, Euglypha, Lesquereusia, Pentagonia, Pseudodifflugia and Scutiglypha. Twelve species not previously reported for Mexico were recorded, along with 13 varieties. The average number of taxa recorded in each lake was eight, and the highest taxonomic richness was 18. The taxon found in the greatest number of lakes was Centropyxis aculeata var. aculeata. Taxonomic richness varied among lakes in the same region. This could reflect lake-specific differences in environmental conditions, underscoring the need for more detailed studies that include collection of data on physical and chemical variables in the lakes. Our results highlighted the need of further studies for the distribution patterns and ecology of lacustrine testate amoebae. Rev. Biol. Trop. 64 (1): 377-397. Epub 2016 March 01.

ResumenLas amebas testadas son organismos eucariontes unicelulares frecuentes en ecosistemas acuáticos. A pesar de su importante rol en estos ecosistemas, y su potencial como bioindicadores y paleoindicadores, son poco estudiados en México. Los principales objetivos de este estudio fueron: 1) incrementar el conocimiento de las amebas testadas en lagos tropicales de México y 2) crear un catálogo de microfotografías electrónicas de barrido de alta calidad que pueda ser usado en futuros estudios ecológicos y paleoambientales. Recolectamos muestras de sedimentos superficiales de 29 lagos, ubicados en la Faja Volcánica Transmexicana, una vez en cada lago durante junio y octubre 2011 y marzo 2013. Los sedimentos se recolectaron con una draga tipo Ekman y se preservaron en etanol anhidro. Las sub-muestras se observaron al microscopio estereoscópico. Para cada especie fueron registrados sus datos morfométricos. En testas circulares fueron medidos el diámetro y la apertura total. En testas irregulares fueron medidos el largo y ancho de la apertura y el tamaño de toda la testa. Si un ejemplar poseía espinas, se seleccionó una al azar y se midió su longitud. El ejemplar mejor preservado de cada taxón fue fotografiado con un microscopio óptico y en microscopio electrónico de barrido (MEB). Encontramos 41 taxa de amebas testadas pertenecientes a los géneros Arcella, Argynnia, Centropyxis, Cucurbitella, Cyclopyxis, Cyphoderia, Difflugia, Euglypha, Lesquereusia, Pentagonia, Pseudodifflugia y Scutiglypha. Se registraron 12 especies y 13 variedades que no estaban reportadas previamente en México. El número promedio de taxa registrados en cada lago fue de ocho, y la riqueza taxonómica mayor fue de 18. El taxón encontrado en el mayor número de lagos fue Centropyxis aculeata var. aculeata. La riqueza taxonómica compartida por lagos de la misma región no fue muy similar. Esto puede reflejar diferencias en las condiciones ambientales, evidenciando la necesidad de elaborar estudios más detallados que incluyan la recolección de datos de las variables físico-químicas en los lagos. Nuestros resultados resaltan la necesidad de estudios posteriores acerca de los patrones de distribución y la ecología de las amebas testadas lacustres.

Testate Amoebae (Amebozoa: Arcellinida) in Tropical Lakes of Central Mexico.

Testate amoebae are common single-celled eukaryotic organisms in aquatic ecosystems. Despite their important role in these ecosystems, and their potential as bioindicators and paleoindicators, they remain poorly studied in Mexico. The major objectives of this study were to: 1) increase knowledge of testate amoebae in Mexico's tropical lakes, and 2) create a catalog of high-quality scanning electron micrographs that can be used for future ecological and paleoenvironmental studies. We collected surface-sediment samples from 29 lakes, located in the Transmexican Volcanic Belt, one at each lake during June and October 2011, and March 2013. Sediments were collected with an Ekman grab and preserved in anhydrous ethanol. Sub-samples were observed under a stereomicroscope and morphometric data for each species were recorded. Total diameter and aperture diameter were measured on circular tests. Irregularly shaped tests were measured for length and width of the aperture and for the size of the whole test. If a specimen possessed spines, the length of one randomly selected spine was measured. The best-preserved specimen of each taxon was photographed with an optical microscope and a scanning electron microscope (SEM). We found 41 taxa of testate amoebae belonging to the genera: Arcella, Argynnia, Centropyxis, Cucurbitella, Cyclopyxis, Cyphoderia, Difflugia, Euglypha, Lesquereusia, Pentagonia, Pseudodifflugia and Scutiglypha. Twelve species not previously reported for Mexico were recorded, along with 13 varieties. The average number of taxa recorded in each lake was eight, and the highest taxonomic richness was 18. The taxon found in the greatest number of lakes was Centropyxis aculeata var. aculeata. Taxonomic richness varied among lakes in the same region. This could reflect lake-specific differences in environmental conditions, underscoring the need for more detailed studies that include collection of data on physical and chemical variables in the lakes. Our results highlighted the need of further studies for the distribution patterns and ecology of lacustrine testate amoebae.

The APPEESFRS Peptide, Restricted by the HLA-B*35:01 Molecule, and the APPEESFRF Variant Derived from an Autologous HIV-1 Strain Induces Polyfunctional Responses in CD8+ T Cells.

Numerous reports have focused on consensus peptides to determine CD8+ T-cell responses; however, few studies evaluated the functional profile using peptides derived from circulating strains of a specific region. We determined the effector profile and maturation phenotype of CD8+ T-cells targeting the consensus APPEESFRS (AS9) epitope and its variant APPEESFRF (AF9), previously identified. The free energy of binding, maturation phenotype, and polyfunctional profile of both peptides were similar. The magnitude of CD8+ T-cell responses to AF9 was greater than the one elicited by AS9, although the difference was not significant. The polyfunctional profile of AF9 was characterized by CD107a/interleukin-2 (IL-2)/macrophage inflammatory protein beta (MIP1ß) and by interferon gamma (IFNγ)/MIP1ß/tumor necrosis factor alpha (TNFα) in response to AS9. TNFα production was significantly higher in response to AF9 than to AS9, and there was a negative correlation between the absolute number of CD8+ T-cell-producing TNFα and the plasma human immunodeficiency virus (HIV) load, suggesting a role of this cytokine in the control of HIV replication.

Non-marine ostracodes from highland lakes in East-central Mexico / Ostrácodos no-marinos de lagos en el altiplano este-centro de México

The ostracode fauna of the neartic-neotropical transitional zone has remained poorly known until this study. Ten ostracode species inhabit ten highland lakes (five maar lakes (phreatic/phreato-magmatic explosion origin), one volcanic-tectonic lake, three natural dams and one man-made dam) in East-central Mexico. Surface sediments from the deepest part and the littoral zone from all studied lakes were collected. Environmental variables (pH, temperature, dissolved oxygen, conductivity, TDS) were measured in situ and parallel water samples for chemical analysis were collected for habitat description. Widely distributed species in the study area (≥5 lakes) include Cypridopsis vidua, Darwinula stevensoni and Eucandona cf. patzcuaro. Limnocytherina axalapasco is an endemic species and was collected in three maar lakes and in one man-made dam. Rare species included: Chlamydotheca arcuata?, Fabaeformiscandona acuminata?, Ilyocypris gibba?, Limnocythere friabilis?, Potamocypris smaragdina? and Potamocypris unicaudata?. Highest species richness (6 spp.) was found in the large and shallow Lake Metztitlán (2.6km², 5.5m deep), with the lake water type HCO3->>SO4²->Cl--- Ca2+>Na+>Mg2+. The rest of studied lakes (<63m, <27km²) had not more than three species. For instance, only two ostracode species were collected in Lake Alchichica, which is the largest, deepest and most saline studied maar lake. Rev. Biol. Trop. 63 (2): 401-425. Epub 2015 June 01.

La fauna de ostrácodos de la zona de transición néartica-neotropical ha sido poco estudiada hasta este estudio. En el este-centro de México, habitan diez especies de ostrácodos en diez lagos: cinco lagos maar (originados por explosiones freáticas/freato-magmáticas), un lago volcánico-tectónico, tres embalses naturales y un embalse artificial. De la parte más profunda y de las zonas litorales de todos los lagos estudiados se recolectaron sedimentos superficiales para el análisis de ostrácodos. También se midieron in situ las variables ambientales: pH, temperatura, oxígeno disuelto, conductividad, SDT, además se recolectaron muestras de agua paralelas para análisis químico con el objetivo de describir el hábitat. Especies con una amplia distribución en el área de estudio (≥5 lagos) incluyen: Cypridopsis vidua, Darwinula stevensoni y Eucandona cf. patzcuaro. Limnocytherina axalapasco es una especie endémica y fue recolectada en tres lagos maar y en el embalse artificial. Especies raras incluyeron: Chlamydotheca arcuata?, Fabaeformiscandona acuminata?, Ilyocypris gibba?, Limnocythere friabilis?, Potamocypris smaragdina? y Potamocypris unicaudata? La riqueza de especies más alta (6 spp.) se encontró en el lago más extenso y somero, lago Metztitlán (2.6km², 5.5m de profundidad), con el tipo de agua HCO3->>SO4²->Cl--- Ca2+>Na+>Mg2+. El resto de lagos estudiados (<63m, <27km²) presentaron no más de tres especies. Por ejemplo, solamente dos especies de ostrácodos fueron recolectadas en el lago Alchichica, el cual es el más extenso, profundo y salino entre los lagos maar estudiados.

On Limnocytherina axalapasco, a new freshwater ostracod (Podocopida: Limnocytheridae) from Mexican crater lakes.

Limnocytherina is a genus conformed by 12 species; its distribution in the American continent is known to be exclusively on the North (neartics), but little is reported about its distribution from Mexico (transition zone) and Central America (Neotropics). Different sampling campaigns were undertaken in three crater lakes from the Axalapascos region in east-central Mexico, during 2008, 2009 and 2011. As a product of these campaings, the new species of Limnocytherina axalapasco was found, which displays some intraspecific variability among populations. In this study, we described the taxonomy, the habitat, the ecological preferences and the larval development of this new species. A total of 10 sediment samples (8 littoral, 2 deepest point) were collected from lakes Alchichica, La Preciosa and Quechulac. We found that L. axalapasco is closely related to two North American species: L. posterolimba and L. itasca as well as one Central American species L. royi comb. nov. With the inclusion of L. axalapasco and L. royi to the genus, the distribution of Limnocytherina is extended to Central America. The four most important distinguishing characters of this new species are: 1) valve surface and margins covered with small, spine-like projections; 2) most of the A1 setae with a highly developed setule at distal part, producing a bifurcate appearance; 3) the upper ramus on the hemipenis is elongated, and by far overpasses dorsal/distal margins, distal lobe is triangular and short, while the hook-like process is prominent, outward orientated, and overpassing the tip of the distal lobe; 4) the UR is moderately developed with seta f3 elongated and setae f1 and f2 short. Considering its ecological characteristics and larval development, L. axalapasco was preferably found in alkaline waters dominated by Cl(-) or HCO3(-) and Na+ or Mg2+, temperatures ranging between 19.1 to 20.3 degrees C, and dissolved oxygen concentrations from 5 to 6.5 mg/L. This species was abundant in deeper (approximately 64m) areas of the saline Alchichica lake, where surface water displayed conductivity values of up to 2 250 microS/cm, and the sand with low percentage of silt resulted the preferred substrate. Along with the description of L. axalapasco, we provide additional information on the hemipenis of L. itasca, L. royi and L. sanctipatricii, and we discuss on the Limnocytherina-type of hemipenis.

On Limnocytherina axalapasco, a new freshwater ostracod (Podocopida: Limnocytheridae) from Mexican crater lakes / Limnocytherina axalapasco, un nuevo ostrácodo dulceacuícola (Podocopida: Limnocytheridae) de lagos de cráter mexicanos

Limnocytherina is a genus conformed by 12 species; its distribution in the American continent is known to be exclusively on the North (neartics), but little is reported about its distribution from Mexico (transition zone) and Central America (Neotropics). Different sampling campaigns were undertaken in three crater lakes from the Axalapascos region in east-central Mexico, during 2008, 2009 and 2011. As a product of these campaings, the new species of Limnocytherina axalapasco was found, which displays some intraspecific variability among populations. In this study, we described the taxonomy, the habitat, the ecological preferences and the larval development of this new species. A total of 10 sediment samples (8 littoral, 2 deepest point) were collected from lakes Alchichica, La Preciosa and Quechulac. We found that L. axalapasco is closely related to two North American species: L. posterolimba and L. itasca as well as one Central American species L. royi comb. nov. With the inclusion of L. axalapasco and L. royi to the genus, the distribution of Limnocytherina is extended to Central America. The four most important distinguishing characters of this new species are: 1) valve surface and margins covered with small, spine-like projections; 2) most of the A1 setae with a highly developed setule at distal part, producing a bifurcate appearance; 3) the upper ramus on the hemipenis is elongated, and by far overpasses dorsal/distal margins, distal lobe is triangular and short, while the hook-like process is prominent, outward orientated, and overpassing the tip of the distal lobe; 4) the UR is moderately developed with seta f3 elongated and setae f1 and f2 short. Considering its ecological characteristics and larval development, L. axalapasco was preferably found in alkaline waters dominated by Cl- or HCO3- and Na+ or Mg2+, temperatures ranging between 19.1 to 20.3°C, and dissolved oxygen concentrations from 5 to 6.5mg/L. This species was abundant in deeper (~64m) areas of the saline Alchichica lake, where surface water displayed conductivity values of up to 2 250μS/cm, and the sand with low percentage of silt resulted the preferred substrate. Along with the description of L. axalapasco, we provide additional information on the hemipenis of L. itasca, L. royi and L. sanctipatricii, and we discuss on the Limnocytherina-type of hemipenis.

Limnocytherina es un género conformado por 12 especies; su distribución en el continente Americano se conoce exclusivamente en el norte (zona neártica), pero se sabe poco de su distribución en México (zona de transición) y Centro América (zona neotropical). Luego de diferentes campañas de muestreo en tres lagos cráter de la región de los Axalapascos en la zona centroeste de México, durante 2008, 2009 y 2011, se encontró a Limnocytherina axalapasco, una nueva especie, que mostró variabilidad intraespecífica entre poblaciones. Un total de 10 muestras de sedimentos (8 del litoral, 2 del punto más profundo) fueron recolectadas de los lagos Alchichica, La Preciosa y Quechulac. L. axalapasco esta estrechamente relacionada con dos especies norteamericanas: L. posterolimba y L. itasca, así como con una especie centroamericana Limnocytherina royi comb. nov. Con la inclusión de L. axalapasco y L. royi al género, la distribución de Limnocytherina se extiende hasta Centro América. Los cuatro caracteres distintivos más importantes de esta nueva especie son: 1) superficie y márgenes de valvas cubiertos por pequeñas proyecciones parecidas a espinas; 2) La mayoría de las setas de A1 tienen una setula muy desarrollada en la zona distal, con apariencia de estar bifurcadas; 3) El ramo superior del hemipene es alargado y por mucho sobrepasa los márgenes dorsal/distal; el lóbulo distal es corto y triangular, mientras que el proceso prensil es prominente, orientado externamente y sobrepasa la longitud del lóbulo distal; 4) el UR esta moderadamente desarrollado con la seta f3 alargada y las setas f1 y f2 cortas. Para esta especie se describe también su hábitat, preferencias ecológicas y desarrollo larvario. L. axalapasco prefiere aguas alcalinas dominadas por Cl- o HCO3 - y Na+ o Mg2+, temperaturas entre 19.1 a 20.3°C y concentraciones de oxígeno disuelto de 5 a 6.5 mg/L. Esta especie es más abundante en las zonas profundas (~64m) del lago salino Alchichica, donde la conductividad del agua es de hasta 2 250μS/cm. Arenas con bajos porcentajes de limo parecen ser el sustrato preferido. Aunado a la descripción de L. axalapasco, proveemos información adicional para los hemipenes de L. itasca, L. royi y L. sanctipatricii, y discutimos el tipo de hemipene en Limnocytherina.

Bioindicators of climate and trophic state in lowland and highland aquatic ecosystems of the Northern Neotropics.

Chironomids, diatoms and microcrustaceans that inhabit aquatic ecosystems of the Northern Neotropics are abundant and diverse. Some species are highly sensitive to changes in water chemical composition and trophic state. This study was undertaken as a first step in developing transfer functions to infer past environmental conditions in the Northern lowland Neotropics. Bioindicator species abundances were related to multiple environmental variables to exploit their use as environmental and paleoenvironmental indicators. We collected and analyzed water and surface sediment samples from 63 waterbodies located along a broad trophic state gradient and steep gradients of altitude (approximately 0-1 560 m.a.s.l.) and precipitation (approximately 400-3200 mm/y), from NW Yucatán Peninsula (Mexico) to southern Guatemala. We related 14 limnological variables to relative abundances of 282 diatom species, 66 chironomid morphospecies, 51 species of cladocerans, 29 non-marine ostracode species and six freshwater calanoid copepods. Multivariate statistics indicated that bicarbonate is the strongest driver of chironomid and copepod distribution. Trophic state is the second most important factor that determines chironomid distribution. Conductivity, which is related to the precipitation gradient and marine influence on the Yucatán Peninsula, is the main variable that shapes diatom, ostracode and cladoceran communities. Diatoms, chironomids and cladocerans displayed higher diversities (H = 2.4-2.6) than ostracodes and copepods (H = 0.7-1.8). Species richness and diversity were greater at lower elevations (< 450 m.a.s.l.) than at higher elevations in Guatemala. Distribution and diversity of bioindicators are influenced by multiple factors including altitude, precipitation, water chemistry, trophic state and human impact.

Bioindicators of climate and trophic state in lowland and highland aquatic ecosystems of the Northern Neotropics

Chironomids, diatoms and microcrustaceans that inhabit aquatic ecosystems of the Northern Neotropics are abundant and diverse. Some species are highly sensitive to changes in water chemical composition and trophic state. This study was undertaken as a first step in developing transfer functions to infer past environmental conditions in the Northern lowland Neotropics. Bioindicator species abundances were related to multiple environmental variables to exploit their use as environmental and paleoenvironmental indicators. We collected and analyzed water and surface sediment samples from 63 waterbodies located along a broad trophic state gradient and steep gradients of altitude (~0-1 560m.a.s.l.) and precipitation (~400-3 200mm/y), from NW Yucatán Peninsula (Mexico) to southern Guatemala. We related 14 limnological variables to relative abundances of 282 diatom species, 66 chironomid morphospecies, 51 species of cladocerans, 29 non-marine ostracode species and six freshwater calanoid copepods. Multivariate statistics indicated that bicarbonate is the strongest driver of chironomid and copepod distribution. Trophic state is the second most important factor that determines chironomid distribution. Conductivity, which is related to the precipitation gradient and marine influence on the Yucatán Peninsula, is the main variable that shapes diatom, ostracode and cladoceran communities. Diatoms, chironomids and cladocerans displayed higher diversities (H=2.4-2.6) than ostracodes and copepods (H=0.7- 1.8). Species richness and diversity were greater at lower elevations (<450m.a.s.l.) than at higher elevations in Guatemala. Distribution and diversity of bioindicators are influenced by multiple factors including altitude, precipitation, water chemistry, trophic state and human impact.

Los quironómidos, diatomeas y microcrustaceos que habitan ecosistemas acuáticos en el norte de los Neotrópicos son abundantes y diversos. Algunas especies son altamente sensibles a cambios en la composición química del agua y en el estado trófico. Este estudio se realizó como el primer paso para desarrollar funciones de transferencia para inferir condiciones ambientales en el norte de las tierras bajas de los Neotrópicos. Es por esto que las abundancias de especies bioindicadoras se relacionaron con múltiples variables ambientales con el fin de explotar al máximo su uso como indicadores ambientales y paleoambientales. Recolectamos y analizamos muestras de agua y de sedimento superficial de 63 cuerpos de agua, ubicados a lo largo de un gradiente trófico y de gradientes marcados de altitud (~0-1 560m.s.n.m.) y de precipitación (~400-3 200mm/año), desde el NO de la Península de Yucatán (México) hasta el sur de Guatemala. Relacionamos 14 variables limnológicas con las abundancias relativas de 282 especies de diatomeas, 66 morfoespecies de quironómidos, 51 especies de cladóceros, 29 especies de ostrácodos no-marinos y seis especies de agua dulce de cladóceros calanoides. La estadística multivariada indicó que el bicarbonato es el principal determinante de la distribución de quironómidos y copépodos. El estado trófico es el segundo factor más importante en determinar la distribución de quironómidos. La conductividad, que está relacionada con el gradiente de precipitación e influencia marina en la Península de Yucatán, es la principal variable en influir las comunidades de diatomeas, ostrácodos y cladóceros. Las diatomeas, quironómidos y cladóceros (H=2.4-2.6) presentaron diversidades más altas que los ostrácodos y copépodos (H=0.7-1.8). La riqueza de especies y la diversidad fueron más altas en las elevaciones bajas (<450m.s.n.m) que en elevaciones altas en Guatemala. La distribución y diversidad de bioindicadores es afectada por múltiples factores incluyendo la altitud, precipitación, composición química del agua, estado trófico y el impacto humano.

Extant freshwater ostracodes (Crustacea: Ostracoda) from Lago Petén Itzá, Guatemala

Ostracode taxonomy has been of great interest because of their possible use as indicator species in climate and ecosystem changes. In Central and South America, few studies have been carried out and this study includes a contribution to the group. Eleven ostracode species were collected in Lago Petén Itzá (~100km2), the second largest lowland lake in Guatemala, and from its inflow tributary, Río Ixlú in November 2005 and February 2008. Twenty-seven surface sediment samples were retrieved at water depths from the littoral zone to the lake’s maximum depth (>160m). Hard and soft parts of ostracodes were analyzed, and each ostracode species was described for taxonomy, size, ecology, biology and geographic distribution. Species recorded include: Candonocypris serratomarginata?, Cypretta brevisaepta?, Cypridopsis okeechobei, Cytheridella ilosvayi, Darwinula stevensoni, Heterocypris punctata, Limnocythere opesta, Physocypria globula, Pseudocandona sp., Stenocypris major and Strandesia intrepida. Most of the species have a neotropical distribution, two are distributed world-wide (D. stevensoni and S. major), and C. okeechobei and P. globula display nearctic and neotropical distributions. We present new records of C. brevisaepta?, C. serratomarginata?, S. major, and S. intrepida in Guatemala. Physocypria globula was misidentified previously in Lago Petén Itzá as Cypria petenensis, Pseudocandona sp. was misidentified as Candona sp., and C. okeechobei was identified in the past as C. vidua. Limnocythere opesta is the only endemic species of the Petén Lake District, Guatemala. The most abundant and widely distributed species in the lake are P. globula, C. okeechobei, and Pseudocandona sp. Species restricted to the littoral zones and water depths <15m are C. brevisaepta?, D. stevensoni, H. punctata, and S. intrepida. Limnocythere opesta, C. ilosvayi, C. okeechobei, and Pseudocandona sp. are distributed from the littoral zone to a depth of 40m. Species collected only in the Ixlú tributary and in a littoral zone on the west side of the lake were C. serratomarginata? and S. major. During November, live adult L. opesta and C. okeechobei were abundant, but no C. brevisaepta? or C. serratomarginata? adults were found. Adult specimens of C. ilosvayi were more abundant in February. In general, ostracodes collected were smaller than those reported in the literature. An accurate taxonomy will improve the use of ostracode fossil assemblages in long sediment cores when reconstructing past climatic and environmental changes in the northern lowland Neotropics. Rev. Biol. Trop. 58 (3): 871-895. Epub 2010 September 01.

La taxonomía de los ostrácodos ha sido de gran interés debido a su posible uso como especies indicadoras de cambios del clima y de los ecosistemas. En América Central y del Sur se han llevado a cabo pocos estudios. Once especies de ostrácodos fueron colectadas en el 2005 y 2008 en el Lago Petén Itzá (~100km²), el segundo lago más grande de Guatemala y en su afluente, el Río Ixlú. Veintisiete muestras de sedimentos superficiales fueron extraídas a diferentes profundidades desde la zona litoral hasta la profundidad máxima (160m) del lago. Partes duras y blandas de los ostracódos colectados fueron analizadas. Este estudio describe cada especie de ostrácodo con respecto a su taxonomía, tamaño, ecología, biología y distribución geográfica. Especies reportadas incluyen: Candonocypris serratomarginata?, Cypretta brevisaepta?, Cypridopsis okeechobei, Cytheridella ilosvayi, Darwinula stevensoni, Heterocypris punctata, Limnocythere opesta, Physocypria globula, Pseudocandona sp., Stenocypris major y Strandesia intrepida. La mayoría de las especies poseen una distribución neotropical, dos tienen una distribución mundial (D. stevensoni and S. major) y C. okeechobei y P. globula tienen una distribución neártica y neotropical. Presentamos un nuevo récord de C. brevisaepta?, C. serratomarginata?, S. major y S. intrepida para Guatemala. Physocypria globula fue identificada erróneamente en el Lago Petén Itzá como Cypria petenensis, Pseudocandona sp. había sido identificada como Candona sp. y C. okeechobei como C. vidua. Limnocythere opesta es una especie endémica de la región. Las especies más abundantes y de mayor distribución en el lago son P. globula, C. okeechobei y Pseudocandona sp. Especies restringidas a zonas litorales y aguas con una pronfundidad <15m son: D. stevensoni, H. punctata y S. intrepida. Limnocythere opesta y C. ilosvayi están distribuidas de la zona litoral a una profundidad de 40m. Especies recolectadas solamente en el afluente Ixlú y en la zona litoral oeste, fueron C. serratomarginata? y S. major. En general, los ostrácodos adultos identificados fueron más pequeños que los tamaños reportados en la literatura. Una correcta taxonomía mejorará el uso de las comunidades de ostrácodos fósiles de núcleos de sedimentos para la reconstrucción climática y ambiental de la región neotropical.

Extant freshwater ostracodes (Crustacea: Ostracoda) from Lago Petén Itzá, Guatemala.

Ostracode taxonomy has been of great interest because of their possible use as indicator species in climate and ecosystem changes. In Central and South America, few studies have been carried out and this study includes a contribution to the group. Eleven ostracode species were collected in Lago Petén Itzá (approximately 100km2), the second largest lowland lake in Guatemala, and from its inflow tributary, Río Ixlú in November 2005 and February 2008. Twenty-seven surface sediment samples were retrieved at water depths from the littoral zone to the lake's maximum depth (>160m). Hard and soft parts of ostracodes were analyzed, and each ostracode species was described for taxonomy, size, ecology, biology and geographic distribution. Species recorded include: Candonocypris serratomarginata?, Cypretta brevisaepta?, Cypridopsis okeechobei, Cytheridella ilosvayi, Darwinula stevensoni, Heterocypris punctata, Limnocythere opesta, Physocypria globula, Pseudocandona sp., Stenocypris major and Strandesia intrepida. Most of the species have a neotropical distribution, two are distributed world-wide (D. stevensoni and S. major), and C. okeechobei and P. globula display nearctic and neotropical distributions. We present new records of C. brevisaepta?, C. serratomarginata?, S. major, and S. intrepida in Guatemala. Physocypria globula was misidentified previously in Lago Petén Itzá as Cypria petenensis, Pseudocandona sp. was misidentified as Candona sp., and C. okeechobei was identified the past as C. vidua. Limnocythere opesta is the only endemic species of the Petén Lake District, Guatemala. The most abundant and widely distributed species in the lake are P. globula, C. okeechobei, and Pseudocandona sp. Species restricted to the littoral zones and water depths <15 m are C. brevisaepta?, D. stevensoni, H. punctata, and S. intrepida. Limnocythere opesta, C. ilosvayi, C. okeechobei, and Pseudocandona sp. are distributed from the littoral zone to a depth of 40m. Species collected only in the Ixlú tributary and in a littoral zone on the west side of the lake were C. serratomarginata? and S. major. During November, live adult L. opesta and C. okeechobei were abundant, but no C. brevisaepta? or C. serratomarginata? adults were found. Adult specimens of C. ilosvayi were more abundant in February. In general, ostracodes collected were smaller than those reported in the literature. An accurate taxonomy will improve the use of ostracode fossil assemblages in long sediment cores when reconstructing past climatic and environmental changes in the northern lowland Neotropics.