Mitochondrial function in skeletal muscle contributes to reproductive endothermy in tegu lizards (Salvator merianae).

AIM: In cyclic climate variations, including seasonal changes, many animals regulate their energy demands to overcome critical transitory moments, restricting their high-demand activities to phases of resource abundance, enabling rapid growth and reproduction. Tegu lizards (Salvator merianae) are ectotherms with a robust annual cycle, being active during summer, hibernating during winter, and presenting a remarkable endothermy during reproduction in spring. Here, we evaluated whether changes in mitochondrial respiratory physiology in skeletal muscle could serve as a mechanism for the increased thermogenesis observed during the tegu's reproductive endothermy. METHODS: We performed high-resolution respirometry and calorimetry in permeabilized red and white muscle fibers, sampled during summer (activity) and spring (high activity and reproduction), in association with citrate synthase measurements. RESULTS: During spring, the muscle fibers exhibited increased oxidative phosphorylation. They also enhanced uncoupled respiration and heat production via adenine nucleotide translocase (ANT), but not via uncoupling proteins (UCP). Citrate synthase activity was higher during the spring, suggesting greater mitochondrial density compared to the summer. These findings were consistent across both sexes and muscle types (red and white). CONCLUSION: The current results highlight potential cellular thermogenic mechanisms in an ectothermic reptile that contribute to transient endothermy. Our study indicates that the unique feature of transitioning to endothermy through nonshivering thermogenesis during the reproductive phase may be facilitated by higher mitochondrial density, function, and uncoupling within the skeletal muscle. This knowledge contributes significant elements to the broader picture of models for the evolution of endothermy, particularly in relation to the enhancement of aerobic capacity.

Differences in Bacterial Communities and Pathogen Indicators of Raw and Lagoon-Stabilized Farm Dairy Effluents.

One practice for handling farm dairy effluent (DE) comprises recycling them to the soil with the challenge of balancing the tradeoff associated with environmental pollution through nutrient and microorganism loading. This study investigated seasonal bacterial community composition, diversity, abundance, and pathogenic indicators in untreated (Raw) and lagoon-stabilized (Lagoon) DE. The correlation between bacterial profiles and DE physicochemical characteristics was also analyzed. Pathogen-indicator bacteria were studied by enumerating viable counts and the bacterial community structure by 16S rRNA gene sequence analysis. Lagoon storage effectively reduced total solids (64%), suspended solids (77%), organic carbon (40%), and total nitrogen (82%), along with total coliforms, Escherichia coli, and enterococci. However, this efficiency was compromised in winter. Lagoon and Raw sample bacterial communities presented different compositions, with several environmental variables correlating to microbial community differences. Lagoon-treated DE exhibited the most diverse bacterial community, dominated by Firmicutes (40%), Proteobacteria (30%), and Bacteroidota (7.6%), whereas raw DE was mainly composed of Firmicutes (76%). Regardless of the season, dominant genera included Trichococcus, Romboutsia, Corynebacterium, and Paeniclostridium. Overall, the study emphasizes the importance of lagoon treatment for DE stabilization, showcasing its role in altering bacterial community composition and mitigating environmental risks associated with pathogens and nutrients, particularly in summer.

Spider-Plant Interaction: The Role of Extrafloral Nectaries in Spider Attraction and Their Influence on Plant Herbivory and Reproduction.

Spiders, abundant and diverse arthropods which occur in vegetation, have received little attention in studies investigating spider-plant interactions, especially in plants which have extrafloral nectaries (EFNs). This study examines whether spiders attracted to EFNs on the plant Heteropterys pteropetala (Malpighiaceae) function as biological protectors, mitigating leaf herbivory and positively impacting plant fitness, through manipulative experiments. Spiders are attracted to EFNs because, in addition to consuming the resource offered by these structures, they also consume the herbivores that are attracted by the nectar. At the same time, we documented the reproductive phenology of the plant studied and the abundance of spiders over time. Our results revealed that the plant's reproductive period begins in December with the emergence of flower buds and ends in April with the production of samarids, fruits which are morphologically adapted for wind dispersal, aligning with the peak abundance of spiders. Furthermore, our results demonstrated that spiders are attracted to plants that exude EFNs, resulting in a positive impact on reducing leaf area loss but with a neutral effect on protecting reproductive structures. By revealing the protective function of spiders' vegetative structures on plants, this research highlights the ecological importance of elucidating the dynamics between spiders and plants, contributing to a deeper understanding of ecosystems.

Influence of water electrolysis on hydrolysis and methanogenesis stages of anaerobic digestion at room temperature: Kinetic and metabolic analysis.

Batch cultures were performed to study hydrolysis and methanogenesis in the presence of an electric field at room temperature (i.e., 23 °C). Kinetic and metabolic analyses using RuO2/Ti electrodes were carried out in short reaction times to avoid biofilm formation, allowing the evaluation of the effect of O2 and H2 produced on anaerobic digestion during the imposition of three electric fields: 1.21, 1.45, and 1.64 V/cm. Results highlighted that at 1.21 V/cm, the electrolysis produced 0.0753 mg O2/L·min, where facultative microorganisms consumed 21 % oxygen, enhancing the hydrolysis phase by 52 %. Additionally, methane production was noticeably improved with an activity of 0.89 ± 0.02 g COD-CH4/g VSS·d, meaning 39 % higher than the control. The imposition of an electric field showed promising results since the methanogenic activity at room temperature was very close to the activities observed in conventional reactors at 35 °C.

Role of a typical swine liquid manure treatment plant in reducing elements of antibiotic resistance.

Biological treatment of swine liquid manure may be a favorable environment for the enrichment of bacteria carrying antibiotic resistance genes (ARGs), raising the alert about this public health problem. The present work sought to investigate the performance of a swine wastewater treatment plant (SWWTP), composed of a covered lagoon biodigester (CLB) followed by three facultative ponds, in the removal of usual pollutants, antibiotics, ARGs (blaTEM, ermB, qnrB, sul1, and tetA), and intI1. The SWWTP promoted a 70% of organic matter removal, mainly by the digester unit. The facultative ponds stood out in the solids' retention carried from the anaerobic stage and contributed to ammonia volatilization. The detected antibiotic in the raw wastewater was norfloxacin (< 0.79 to 60.55 µg L-1), and the SWWTP seems to equalize peaks of norfloxacin variation probably due to sludge adsorption. CLB reduced the absolute abundance of ARGs by up to 2.5 log, while the facultative stage does not seem to improve the quality of the final effluent in terms of resistance elements. Considering the relative abundances, the reduction rates of total and ARG-carrying bacteria appear to be similar. Finally, correlation tests also revealed that organic matter and solids control in liquid manure treatment systems could help reduce the spread of ARGs after the waste final disposal.

Change in the composition of fauna associated with Pocillopora spp. (Scleractinia, Pocilloporidae) following transplantation

Introduction: Associated fauna comprises most of the diversity of a coral reef and performs ecological functions essential to the reef's survival. Since Pocillopora corals harbor an important associated fauna, reef restoration efforts are underway in Golfo Dulce, Costa Rica, to preserve them. Objective: To describe changes in cryptofauna and fish communities associated with Pocillopora colonies to better understand the succession of associated fauna following transplantation. Methods: An experimental patch of 30 nursery-grown Pocillopora colonies and a control patch containing no colonies were monitored for 8 months following transplantation in Golfo Dulce. Cryptofauna within each colony and fish within each patch were observed using SCUBA to quantify temporal changes in the abundance, diversity, and community structure of the colonies. Results: The abundance and diversity of cryptofauna increased throughout the experiment. Obligate symbiont decapods were the most abundant. The composition of the community of cryptofauna differed between periods with fish in the genus Scarus as the main contributor to any differences. The increase in abundance and diversity of cryptofauna and fish may reflect coral growth and the corresponding availability of space and environmental complexity in the experimental patch. The composition of the cryptofauna communities was generally consistent with other studies. However, a high density of decapod symbionts could suggest that without other Pocillopora colonies to move to, they may crowd together despite their aggressive tendencies. Conclusions: Pocillopora colonies will experience an increase in symbionts that could positively contribute to the health and survival of the coral following transplantation.

Introducción: La fauna asociada comprende la mayor parte de la diversidad de un arrecife de coral y realiza funciones ecológicas esenciales para la supervivencia del arrecife. Dado que los corales Pocillopora albergan una importante fauna asociada, se están realizando esfuerzos de restauración de arrecifes en Golfo Dulce, Costa Rica, para preservarlos. Objetivo: Describir los cambios en la comunidad de criptofauna y peces asociados a las colonias de Pocillopora para comprender mejor la sucesión de la fauna asociada después del trasplante. Métodos: Un parche experimental de 30 colonias de Pocillopora cultivadas en vivero y un parche de control que no contenía colonias fueron monitoreados durante 8 meses después del trasplante en Golfo Dulce. La criptofauna dentro de cada colonia y los peces dentro de cada parche se observaron usando SCUBA para cuantificar los cambios temporales en la abundancia, diversidad y estructura de la comunidad de las colonias. Resultados: La abundancia y diversidad de criptofauna aumentó a lo largo del experimento. Los decápodos simbiontes obligados fueron los más abundantes. La composición de la comunidad de criptofauna difirió entre períodos con peces del género Scarus como el principal contribuyente a cualquier diferencia. El aumento en la abundancia y diversidad de criptofauna y peces puede reflejar el crecimiento de coral y la correspondiente disponibilidad de espacio y complejidad ambiental en el parche experimental. La composición de las comunidades de criptofauna fue generalmente consistente con otros estudios. Sin embargo, una alta densidad de simbiontes decápodos podría sugerir que, sin otras colonias de Pocillopora a las que trasladarse, pueden amontonarse a pesar de sus tendencias agresivas. Conclusiones: Las colonias de Pocillopora experimentarán un aumento de simbiontes que podrían contribuir positivamente a la salud y supervivencia del coral después del trasplante.

The role of spine length in crustacean and fish associations with echinoids at Los Cabos, Baja California Sur, Mexico / El papel de la longitud de la espina en la asociación de crustáceos y peces con equinoideos en Los Cabos, Baja California Sur, México

Introduction: Echinoids (sea urchins) provide shelter for a variety of facultative or obligatory ectosymbionts. Objective: To evaluate the hypothesis that decapods and fishes prefer to associate with echinoid individuals and species that have longer spines. Methods: We visually studied the frequency of decapod crustaceans and fishes associated with echinoids in shallow water (< 4 m) and deeper water (5-20 m) at Los Cabos, Baja California Sur, Mexico, during 1-6 January 2019. Results: We inspected 1 058 echinoids of six species. Five decapod species associated with three species of echinoids. When compared with other echinoid species, in shallow water, decapods associated 5.1 times more often with the longest-spined echinoid Diadema mexicanum (7.0 times more decapods per individual D. mexicanum); in deeper water, association frequency was similar for all echinoid species. Fourteen fish species associated with four echinoid species. In shallow water, fishes associated 2.6 times more with D. mexicanum (4.5 times more fishes per individual). There was no preferred echinoid species in deeper water. Longer-spined D. mexicanum had more decapods and fishes. Associations were more frequent in shallow water. Multiple individuals and species of decapods and fish often associated together with a single D. mexicanum. The decapod that presumably is Tuleariocaris holthuisi showed a possible obligatory association with one of the equinoids (D. mexicanum); the other decapods and all fish species are facultative associates. Conclusion: Our results support the hypothesis that decapods and fishes associate most frequently with echinoids with the longest spines, presumably to reduce the risk of predation.

Introducción: Los equinoideos (erizos de mar) brindan refugio a una variedad de ectosimbiontes facultativos u obligatorios. Objetivo: Evaluar la hipótesis de que los decápodos y los peces prefieren asociarse con individuos y especies de equinoideos con espinas más largas. Métodos: Estudiamos visualmente la frecuencia de crustáceos decápodos y peces asociados con equinoideos en aguas poco profundas (< 4 m) y aguas más profundas (5-20 m) en Los Cabos, Baja California Sur, México, del 1-6 de enero 2019. Resultados: Examinamos 1 058 equinoideos de seis especies. Cinco especies de decápodos se asociaron con tres especies de equinoideos. Al comparar con otras especies de equinoideos, en aguas poco profundas, los decápodos se asociaron 5.1 veces más frecuentemente con la especie de equinoideo de espinas más largas, Diadema mexicanum (7.0 veces más decápodos por individuo en D. mexicanum); en aguas más profundas, la frecuencia fue similar para todas las especies de equinoideos. Catorce especies de peces se asociaron con 4 especies de equinoideos. En aguas poco profundas, los peces se asociaron 2.6 veces más con D. mexicanum (4.5 veces más peces por individuo). No hubo preferencia por una especie de equinoideo en aguas más profundas. Individuos de D. mexicanum con espinas largas tuvieron más asociación con decápodos y peces. Las asociaciones se dieron con mayor frecuencia en aguas poco profundas. Múltiples individuos y especies de decápodos y peces a menudo se asociaron con un solo D. mexicanum. Un decápodo que presumiblemente es Tuleariocaris holthuisi mostró una posible asociación obligatoria con uno de los equinoideos (D. mexicanum); las otras especies de decápodos y todas las especies de peces presentaron asociaciones facultativas. Conclusión: Nuestros resultados apoyan la hipótesis de que los decápodos y los peces se asociaron con mayor frecuencia con los equinoideos con las espinas más largas, presumiblemente para reducir el riesgo de depredación.

Variation of Residual Sexuality Rates along Reproductive Development in Apomictic Tetraploids of Paspalum.

Most apomictic plants are facultative, maintaining the ability to reproduce sexually at different frequencies depending on the taxa, ploidy, and reproductive stage. In this context, Paspalum species are good model systems for studies evaluating the varying levels of apomixis expression. We aimed to identify, in apomictic tetraploid Paspalum species, the degree of apomixis and residual sexuality in three stages of reproductive development, and if their expression varies along them in order to predict their realized impact on the genetic diversity of future generations. Three main stages in the reproductive development (i.e., ovule, seed, and progeny) were studied in tetraploids from populations of P. cromyorhizon and P. maculosum. Mature ovules were studied using cytoembryological analysis, seeds by flow cytometry, and progeny tests with molecular markers. The expression of sexuality and apomixis was compared in each stage. We observed a decline in expression of sexual reproduction through the consecutive stages, jointly with an increase of apomixis expression. Both species showed at least one tetraploid plant capable of producing progeny by sexual means. These small rates of sexually originated progeny prove the ability of apomictic plants to produce low levels of genetic variation through rare events of sexuality. This study also demonstrates the importance of analyzing different reproductive stages in order to get a whole picture of the reproductive outcomes in plant evolution.

A matter of time: regulatory events behind the synchronization of C4 and crassulacean acid metabolism in Portulaca oleracea.

Portulaca species can switch between C4 and crassulacean acid metabolism (CAM) depending on environmental conditions. However, the regulatory mechanisms behind this rare photosynthetic adaptation remain elusive. Using Portulaca oleracea as a model system, here we investigated the involvement of the circadian clock, plant hormones, and transcription factors in coordinating C4 and CAM gene expression. Free-running experiments in constant conditions suggested that C4 and CAM gene expression are intrinsically connected to the circadian clock. Detailed time-course, drought, and rewatering experiments revealed distinct time frames for CAM induction and reversion (days versus hours, respectively), which were accompanied by changes in abscisic acid (ABA) and cytokinin metabolism and signaling. Exogenous ABA and cytokinins were shown to promote and repress CAM expression in P. oleracea, respectively. Moreover, the drought-induced decline in C4 transcript levels was completely recovered upon cytokinin treatment. The ABA-regulated transcription factor genes HB7, NFYA7, NFYC9, TT8, and ARR12 were identified as likely candidate regulators of CAM induction following this approach, whereas NFYC4 and ARR9 were connected to C4 expression patterns. Therefore, we provide insights into the signaling events controlling C4-CAM transitions in response to water availability and over the day/night cycle, highlighting candidate genes for future functional studies in the context of facultative C4-CAM photosynthesis.

Identification of key microorganisms in facultative stabilization ponds from dairy industries, using metagenomics.

Wastewater stabilization ponds are a natural form of wastewater treatment. Their low operation and maintenance costs have made them popular, especially in developing countries. In these systems, effluents are retained for long periods of time, allowing the microbial communities present in the ponds to degrade the organic matter present, using both aerobic and anaerobic processes. Even though these systems are widespread in low income countries, there are no studies about the microorganisms present in them and how they operate. In this study, we analised the microbial communities of two serial full-scale stabilization ponds systems using whole genome shotgun sequencing. First, a taxonomic profiling of the reads was performed, to estimate the microbial diversity. Then, the reads of each system were assembled and binned, allowing the reconstruction of 110 microbial genomes. A functional analysis of the genomes allowed us to find how the main metabolic pathways are carried out, and we propose several organisms that would be key to this kind of environment, since they play an important role in these metabolic pathways. This study represents the first genome-centred approach to understand the metabolic processes in facultative ponds. A better understanding of these microbial communities and how they stabilize the effluents of dairy industries is necessary to improve them and to minimize the environmental impact of dairy industries wastewater.

Sex, not social behavior, predicts fecal glucocorticoid metabolite concentrations in a facultatively social rodent, the highland tuco-tuco (Ctenomys opimus).

Social relationships may influence circulating glucocorticoid levels, particularly in group-living species in which individuals regularly engage in interactions with conspecifics. The effects of such interactions appear to vary, with greater social contact being associated with increased glucocorticoid concentrations in some species but decreased concentrations in others. These distinct responses raise intriguing questions regarding relationships among social behavior, individual phenotypes, and glucocorticoid physiology. To explore such relationships in a free-living mammal with a dynamic social organization, we quantified variation in baseline glucocorticoids in a population of highland tuco-tucos (Ctenomys opimus) from Jujuy Province, Argentina. These subterranean rodents are facultatively social, with lone and group-living individuals regularly occurring within the same population. To assess potential endocrine correlates of this behavioral variability, we examined differences in baseline fecal glucocorticoid metabolite (fGCm) concentrations as a function of social group size and composition as well as several metrics of social behavior derived from social network analyses. Despite marked variability in social relationships among the 37 (12 male, 25 female) free-living tuco-tucos sampled, none of the measures of social behavior examined were significant predictors of variation in fGCm concentrations. In contrast, individual variation in glucocorticoid metabolites was best explained by sex, with males having higher fGCm concentrations than females. These analyses provide the first characterization of the glucocorticoid physiology of highland tuco-tucos and underscore the potential importance of intrinsic phenotypic factors (e.g., sex) in shaping glucocorticoid variation in free-living mammals.

Queens remate despite traumatic mating in stingless bees.

Males can control female reproduction using genital plugs to impede access by rivals. In social bees, ants, and wasps, plugging may involve traumatic mating, with females being harmed. In stingless bees, chances are that plugs may promote ovarian activan, and are thought to ensure single mating-a general tendency among the social Hymenoptera. However, understanding on relationships between mating plugs, traumatic mating, and mating systems in stingless bees remains limited. To address this, we (1) compared mated queens of 7 Neotropical species to understand the patterns of copulatory marks in females and (2) compared pre- and post-mating genitalia of males and females in Melipona fasciculata to depict plug functional morphology. Data revealed an unprecedented consequence of mating in stingless bees: the characteristic marks left by mating plugs on female abdomens and the inferences that can be made from them. To our surprise, in 1 species M. fasciculata we found that queens retain the plug long after mating, and may carry it for the rest of their lives. All the other 6 species retained the plug for only a short period. Remated queens were only found in M. seminigra, whose multiple copulatory marks match previous findings of polyandry in this species. Our study shows that queens can remate, and suggests that male genital morphology may determine in part the time persistence of plugs. We conclude that traumatic mating plugs do not fully prevent remating in stingless bees and that mating systems are not uniform in this group. Nonetheless, exceptional cases of facultative polyandry in social insects-for example, when mating plugs fail-may confirm a general tendency for single mating in close link with efficient mating plugs.

The effects of anaerobic reactor post-treatments by rapid filtration systems and conventional techniques.

Although anaerobic reactors are an excellent alternative in the treatment of domestic effluents, they have the disadvantage of requiring post-treatment. Many technologies have been studied and, recently, rapid filtration systems have been presented as a viable alternative for post-treatment. This work compared post-treatment techniques for anaerobic upflow sludge blanket (UASB) reactors by rapid filtration systems (double filtration (DF); triple filtration with clinoptilolite (TFc); and triple filtration with activated carbon (TFac)) to conventional systems (facultative pond (FP); biological filter (BF); biological filter with recirculation and decantation (BFD)), verifying their potential for improvement of the final effluent quality. The UASB effluent post-treatments by FP, BF, BFD, DF, TFc, and TFac were evaluated. The removal of turbidity in both BFD and FP post-treatments was below 75%. The DF, TFc, and TFac treatments showed over 99% removal of the same parameters. COD removal in the FP, BF, and BFD post-treatments was over 10%, while in the DF, TFc, and TFac treatments, it was over 80%. The greatest total phosphorus removal was observed in TFc and TFac, whose values were over 99%. The best removal of ammoniacal nitrogen, 99% was observed in the TFc treatment. Regarding Al, Cd, Cr, Cu, Mn, Ni, Pb, and Zn removal, all rapid filtration systems showed better performance when compared to conventional systems. The DF, TFc, and TFac systems showed over 90% removal of most metals evaluated, while the FP and BF treatments presented values below 50% for most metals, and in the BFD system, the removal values were below 80% for most metals. The results indicate that rapid filtration systems were better at removing all evaluated parameters when compared to conventional systems.

Cardiac contractility of the African sharptooth catfish, Clarias gariepinus: role of extracellular Ca2+, sarcoplasmic reticulum, and ß-adrenergic stimulation.

This study investigated the dependence of contraction from extracellular Ca2+, the presence of a functional sarcoplasmic reticulum (SR), and the effects of ß-adrenergic stimulation using isometric cardiac muscle preparations. Moreover, the expression of Ca2+-handling proteins such as SR-Ca2+-ATPase (SERCA), phospholamban (PLN), and Na+/Ca2+ exchanger (NCX) were also evaluated in the ventricular tissue of adult African sharptooth catfish, Clarias gariepinus, a facultative air-breathing fish. In summary, we observed that (1) contractility was strongly regulated by extracellular Ca2+; (2) inhibition of SR Ca2+-release by application of ryanodine reduced steady-state force production; (3) ventricular myocardium exhibited clear post-rest decay, even in the presence of ryanodine, indicating a decrease in SR Ca2+ content and NCX as the main pathway for Ca2+ extrusion; (4) a positive force-frequency relationship was observed above 60 bpm (1.0 Hz); (5) ventricular tissue was responsive to ß-adrenergic stimulation, which caused significant increases in twitch force, kept a linear force-frequency relationship from 12 to 96 bpm (0.2 to Hz), and improved the cardiac pumping capacity (CPC); and (6) African catfish myocardium exhibited similar expression patterns of NCX, SERCA, and PLN, corroborating our findings that both mechanisms for Ca2+ transport across the SR and sarcolemma contribute to Ca2+ activator. In conclusion, this fish species displays great physiological plasticity of E-C coupling, able to improve the ability to maintain cardiac performance under physiological conditions to ecological and/or adverse environmental conditions, such as hypoxic air-breathing activity.

Genome Mining and Molecular Networking-Based Metabolomics of the Marine Facultative Aspergillus sp. MEXU 27854.

The marine-facultative Aspergillus sp. MEXU 27854, isolated from the Caleta Bay in Acapulco, Guerrero, Mexico, has provided an interesting diversity of secondary metabolites, including a series of rare dioxomorpholines, peptides, and butyrolactones. Here, we report on the genomic data, which consists of 11 contigs (N50~3.95 Mb) with a ~30.75 Mb total length of assembly. Genome annotation resulted in the prediction of 10,822 putative genes. Functional annotation was accomplished by BLAST searching protein sequences with different public databases. Of the predicted genes, 75% were assigned gene ontology terms. From the 67 BGCs identified, ~60% belong to the NRPS and NRPS-like classes. Putative BGCs for the dioxomorpholines and other metabolites were predicted by extensive genome mining. In addition, metabolomic molecular networking analysis allowed the annotation of all isolated compounds and revealed the biosynthetic potential of this fungus. This work represents the first report of whole-genome sequencing and annotation from a marine-facultative fungal strain isolated from Mexico.

Variable tropical moisture and food availability underlie mixed winter space-use strategies in a migratory songbird.

Identifying environmental correlates driving space-use strategies can be critical for predicting population dynamics; however, such information can be difficult to attain for small mobile species such as migratory songbirds. We combined radio-telemetry and high-resolution GPS tracking to examine space-use strategies under different moisture gradients for wood thrush (Hylocichla mustelina). We explored the role moisture plays in driving food abundance and, in turn, space-use strategies at a wintering site in Belize across 3 years. Individuals occupying drier habitats experienced lower food abundance and poorer body condition. Using data from our radio-tracked study population and GPS tracking from across five breeding populations, we detected low rates of overwinter site persistence across the wood thrush wintering range. Contrary to expectations, individuals in wetter habitats were more likely to engage in permanent mid-winter relocations, up to 148 km. We suggest facultative movements are instead a condition-dependent strategy that enables wintering wood thrush to locate alternative habitat as food availability declines throughout the dry season. Increased aridity is predicted across the wintering range of wood thrush, and future research should delve deeper into understanding how moisture impacts within and between season space-use dynamics and its ultimate impact on the population dynamics of this declining species.

Phages in Anaerobic Systems.

Since the discovery of phages in 1915, these viruses have been studied mostly in aerobic systems, or without considering the availability of oxygen as a variable that may affect the interaction between the virus and its host. However, with such great abundance of anaerobic environments on the planet, the effect that a lack of oxygen can have on the phage-bacteria relationship is an important consideration. There are few studies on obligate anaerobes that investigate the role of anoxia in causing infection. In the case of facultative anaerobes, it is a well-known fact that their shifting from an aerobic environment to an anaerobic one involves metabolic changes in the bacteria. As the phage infection process depends on the metabolic state of the host bacteria, these changes are also expected to affect the phage infection cycle. This review summarizes the available information on phages active on facultative and obligate anaerobes and discusses how anaerobiosis can be an important parameter in phage infection, especially among facultative anaerobes.

C4 and crassulacean acid metabolism within a single leaf: deciphering key components behind a rare photosynthetic adaptation.

Although biochemically related, C4 and crassulacean acid metabolism (CAM) systems are expected to be incompatible. However, Portulaca species, including P. oleracea, operate C4 and CAM within a single leaf, and the mechanisms behind this unique photosynthetic arrangement remain largely unknown. Here, we employed RNA-seq to identify candidate genes involved exclusively or shared by C4 or CAM, and provided an in-depth characterization of their transcript abundance patterns during the drought-induced photosynthetic transitions in P. oleracea. Data revealed fewer candidate CAM-specific genes than those recruited to function in C4 . The putative CAM-specific genes were predominantly involved in night-time primary carboxylation reactions and malate movement across the tonoplast. Analysis of gene transcript-abundance regulation and photosynthetic physiology indicated that C4 and CAM coexist within a single P. oleracea leaf under mild drought conditions. Developmental and environmental cues were shown to regulate CAM expression in stems, whereas the shift from C4 to C4 -CAM hybrid photosynthesis in leaves was strictly under environmental control. Moreover, efficient starch turnover was identified as part of the metabolic adjustments required for CAM operation in both organs. These findings provide insights into C4 /CAM connectivity and compatibility, contributing to a deeper understanding of alternative ways to engineer CAM into C4 crop species.

Identificación de microbiota bucal en caninos en estado de abandono / Identification of Bucal Microbiota in Canines in State of Abandonment

Resumen Objetivo. Describir la microbiota que se encuentra en la cavidad bucal de caninos en condición de abandono de la Fundación Razas Únicas en el municipio de Chía -Cundinamarca. Métodos. Para el estudio se tomaron 29 muestras orales con escobillón a 23 caninos de la Fundación Razas Únicas del municipio de Chía - Cundinamarca. 23 muestras se recolectaron para identificación de bacterias aerobias y anaerobias facultativas, las cuales se transportaron en medio líquido tripticasa soya y 6 muestras para recuperación de bacterias anaerobias estrictas transportadas en medio VMGA-III. El aislamiento de los microorganismos se realizó en medios selectivos y la identificación con el sistema BD BBL™ Crystal™. Resultados. De las 29 muestras analizadas se aislaron 59 bacterias, entre ellas 15 géneros y 15 especies diferentes como; Escherichia coli, Proteus mirabilis, Citrobacter freundii, Enterobacter sakazakii, Enterobacter cloacae, Enterococcus durans, Enterococcus faecalis, Eikenella corrodens, Porphyromonas endodontalis, Fusobacterium spp y Capnocytophaga spp. De acuerdo con la revisión de la literatura, las bacterias anaerobias encontradas están principalmente relacionadas con enfermedad periodontal y las enterobacterias con contaminación oro-fecal.

Abstract Objective. To describe the microbiota found in the oral cavity of canines in condition of abandonment of the Razas Únicas Foundation in the municipality of Chía - Cundinamarca. Methods. For the study, 29 oral samples were taken with a brush from 23 canines from the Razas Únicas Foundation of the municipality of Chía - Cundinamarca. 23 samples were collected for identification of facultative aerobic and anaerobic bacteria, which were transported in soybean tripticase liquid medium and 6 samples for recovery of strict anaerobic bacteria transported in VMGA-III medium. The isolation of the microorganisms was carried out in selective media and identification with the BD BBL™ Crystal™ system. Results. From the 29 samples analyzed, 59 bacteria were isolated, including 15 genera and 15 different species such as Escherichia coli, Proteus mirabilis, Citrobacter freundii, Enterobacter sakazakii, Enterobacter cloacae, Enterococcus durans, Enterococcus faecalis, Eikenella corrodens, Porphyromonas endodontalis, Fusobacterium spp and Capnocytophaga spp. According to the review of the literature, the anaerobic bacteria found are mainly related to periodontal disease and the enterobacteria with oral-fecal contamination.

Evidence for the facultative intracellular behaviour of the fish pathogen Vibrio ordalii.

Vibrio ordalii is an extracellular, Gram-negative bacterium that produces vibriosis in salmonids. While pathogenesis is not fully understood, this bacterium has numerous likely genes for adhesion, colonization, invasion factors and, as recently suggested, intracellular behaviour. Therefore, this study aimed to clarify possible intracellular behaviour for V. ordalii Vo-LM-18 and ATCC 33509T in the fish-cell lines SHK-1 and CHSE-214. Confocal microscopy revealed Vo-LM-18 and ATCC 33509T inside cytoplasm in both fish-cell lines at 4 hr post-inoculation (hpi). At 8 and 16 hpi, the proportion of fish cells invaded by both strains increased. Moreover, intracellular V. ordalii were observed after 8 hpi inside mouse embryonic fibroblasts (MEF), demonstrating that entry was not due to a cellular phagocytosis process. Flow cytometry confirmed immunocytochemistry results, with both V. ordalii evidencing statistically significant differences in the number of infected cells between 8 and 16 hpi. Interestingly, V. ordalii infection did not significantly damage fish cells, as determined by LDH liberation. Viable counts at 8 hpi detected, on average for both lines, 176 ± 47 CFU/ml of culturable intracellular Vo-LM-18 and ATCC 33509T cells. These in vitro findings support the facultative intracellular behaviour of V. ordalii and may be of importance for understanding pathogenicity and survival in aquatic environments.