Phylogenetic Relationships of Avian Cestodes from Brine Shrimp and Congruence with Larval Morphology.

Determining molecular markers for parasites provides a useful tool for their identification, particularly for larval stages with few distinguishable diagnostic characters. Avian cestodes play a key role in the food webs and biodiversity of hypersaline wetlands, yet they remain understudied. Using naturally infected Artemia, we identified cestode larvae (cysticercoids), assessed their genetic diversity, and explored phylogenetic relationships in relation to larval morphology and waterbird final hosts. We obtained partial 18S rDNA sequences for 60 cysticercoids of the family Hymenolepidae infecting Artemia spp. from seven localities and three countries (Spain, the USA, and Chile). We present the first DNA sequences for six taxa: Confluaria podicipina, Fimbriarioides sp., Flamingolepis liguloides, Flamingolepis sp. 1, Flamingolepis sp. 2, and Hymenolepis californicus. Intraspecific sequence variation (0.00-0.19% diversity) was lower than intergroup genetic distance (0.7-14.75%). Phylogenetic analysis revealed three main clades: 1-Flamingolepis, 2-Fimbriarioides, 3-Confluaria and Hymenolepis, all of which separated from hymenolepidids from mammals and terrestrial birds. This clear separation among taxa is congruent with previous morphological identification, validating the 18S gene as a useful marker to discriminate at generic/species level. Working with intermediate hosts allows the expansion of knowledge of taxonomic and genetic diversity of cestodes in wildlife, as well as elucidation of their life cycles.

Epigenetic variation mediated by lncRNAs accounts for adaptive genomic differentiation of the endemic blue mussel Mytiluschilensis.

Epigenetic variation affects gene expression without altering the underlying DNA sequence of genes controlling ecologically relevant phenotypes through different mechanisms, one of which is long non-coding RNAs (lncRNAs). This study identified and evaluated the gene expression of lncRNAs in the gill and mantle tissues of Mytilus chilensis individuals from two ecologically different sites: Cochamó (41°S) and Yaldad (43°S), southern Chile, both impacted by climatic-related conditions and by mussel farming given their use as seedbeds. Sequences identified as lncRNAs exhibited tissue-specific differences, mapping to 3.54 % of the gill transcriptome and 1.96 % of the mantle transcriptome, representing an average of 2.76 % of the whole transcriptome. Using a high fold change value (≥|100|), we identified 43 and 47 differentially expressed lncRNAs (DE-lncRNAs) in the gill and mantle tissue of individuals sampled from Cochamó and 21 and 17 in the gill and mantle tissue of individuals sampled from Yaldad. Location-specific DE-lncRNAs were also detected in Cochamó (65) and Yaldad (94) samples. Via analysis of the differential expression of neighboring protein-coding genes, we identified enriched GO terms related to metabolic, genetic, and environmental information processing and immune system functions, reflecting how the impact of local ecological conditions may influence the M. chilensis (epi)genome expression. These DE-lncRNAs represent complementary biomarkers to DNA sequence variation for maintaining adaptive differences and phenotypic plasticity to cope with natural and human-driven perturbations.

Chromosome-Level Genome Assembly of the Blue Mussel Mytilus chilensis Reveals Molecular Signatures Facing the Marine Environment.

The blue mussel Mytilus chilensis is an endemic and key socioeconomic species inhabiting the southern coast of Chile. This bivalve species supports a booming aquaculture industry, which entirely relies on artificially collected seeds from natural beds that are translocated to diverse physical-chemical ocean farming conditions. Furthermore, mussel production is threatened by a broad range of microorganisms, pollution, and environmental stressors that eventually impact its survival and growth. Herein, understanding the genomic basis of the local adaption is pivotal to developing sustainable shellfish aquaculture. We present a high-quality reference genome of M. chilensis, which is the first chromosome-level genome for a Mytilidae member in South America. The assembled genome size was 1.93 Gb, with a contig N50 of 134 Mb. Through Hi-C proximity ligation, 11,868 contigs were clustered, ordered, and assembled into 14 chromosomes in congruence with the karyological evidence. The M. chilensis genome comprises 34,530 genes and 4795 non-coding RNAs. A total of 57% of the genome contains repetitive sequences with predominancy of LTR-retrotransposons and unknown elements. Comparative genome analysis of M. chilensis and M. coruscus was conducted, revealing genic rearrangements distributed into the whole genome. Notably, transposable Steamer-like elements associated with horizontal transmissible cancer were explored in reference genomes, suggesting putative relationships at the chromosome level in Bivalvia. Genome expression analysis was also conducted, showing putative genomic differences between two ecologically different mussel populations. The evidence suggests that local genome adaptation and physiological plasticity can be analyzed to develop sustainable mussel production. The genome of M. chilensis provides pivotal molecular knowledge for the Mytilus complex.

Administration of Beta-Nerve Growth Factor during the Preovulatory Stage Improves Endocrine and Luteal Function in Dairy Heifers.

The neurotrophin beta-nerve growth factor (NGF), which is present in the semen of different mammals, elicits potent ovulatory and luteotrophic actions in llamas following systemic administration. Here, we determine if purified NGF given intramuscularly (IM) during the preovulatory stage affects the corpus luteum (CL), hormone production, endometrial gene expression, and pregnancy rate of dairy heifers. Holstein-Friesian heifers were estrus-synchronized using estradiol benzoate (EB) plus an intravaginal progesterone (P4) device (DIB). After eight days, the device was removed and cloprostenol was given IM; the next day (day 9), heifers received EB IM plus one of the following: (i) 1 mg of NGF (NGF D9 group), (ii) 1 mg of NGF 32 h after EB (NGF D10 group), or (iii) phosphate buffer saline (control group). To measure pregnancy rates, heifers were treated similarly, then artificially inseminated with sexed semen 48-52 h after DIB removal, then an ultrasound was conducted 30 days after insemination. The females given NGF along with EB (NGF D9) showed significantly higher luteinizing hormone (LH) concentrations, larger CL vascular areas, and higher plasma P4 concentrations than the NGF D10 and control animals. Downregulation of the P4 receptor (PGR), and upregulation of both lipoprotein lipase (LPL) and Solute Carrier Family 6 member 14 (SLC6A14) endometrial genes, were detected in NGF D9 heifers. Furthermore, these heifers had a 10% higher pregnancy rate than the control group. We conclude that the higher P4 output, in response to the early NGF administration, led to the enhanced gene expression of transcripts related to uterine receptivity that may result in enhanced pregnancy rates.

Ovulation Induced by Intrauterine Seminal Plasma Increases Total Protein, PGE2, IL-8, and IL-1ß in Uterine Fluid of Llamas (Lama glama).

The establishment of a state of immunotolerance in the female reproductive tract is important for embryo development, implantation and placentation. Llamas are induced ovulators and more than 98% of pregnancies occur in the left uterine horn. The objective of this study was to determine the uterine immune response of llamas in different stages of the reproductive cycle. Adult llamas (n = 20) were examined daily by transrectal ultrasonography to determine follicular growth and then randomly assigned to four groups: Follicular phase (n = 5); Luteal phase induced by an intramuscular administration of 50 ug of GnRH analogue (n = 5); Luteal phase induced by intrauterine infusion of seminal plasma (n = 5); and Luteal phase induced by mating (n = 5). Uterine fluid was collected separately from both uterine horns by non-surgical flushing to determine the presence of cells, total proteins and concentration of IL-1ß, IL-6, IL-8, IFN γ, TNF-α and PGE2. Inflammatory cells were not observed in the uterine fluid and total protein pattern and inflammatory mediators did not differ between the left and the right horn amongst groups. Llamas treated with an intrauterine infusion of seminal plasma showed the highest concentration of total proteins, inflammatory cytokines PGE2, IL-8 and IL-1ß in the uterine fluid. In conclusion, seminal plasma is made up of significant numbers of signaling molecules that are able to modify the uterine immune response in llamas.

Intraspecies variation of the mitochondrial genome: An evaluation for phylogenetic approaches based on the conventional choices of genes and segments on mitogenome.

Intraspecies nucleotide sequence variation is a key to understanding the evolutionary history of a species, such as the geographic distribution and population structure. To date, numerous phylogenetic and population genetics studies have been conducted based on the sequences of a gene or an intergenic region on the mitochondrial genome (mtDNA), such as cytochrome c oxidase subunits or the D-loop. To evaluate the credibility of the usage of such 'classic' markers, we compared the phylogenetic inferences based on the analyses of the partial and entire mtDNA sequences. Importantly, the phylogenetic reconstruction based on the short marker sequences did not necessarily reproduce the tree topologies based on the analyses of the entire mtDNA. In addition, analyses on the datasets of various organisms revealed that the analyses based on the classic markers yielded phylogenetic trees with poor confidence in all tested cases compared to the results based on full-length mtDNA. These results demonstrated that phylogenetic analyses based on complete mtDNA sequences yield more insightful results compared to those based on mitochondrial genes and segments. To ameliorate the shortcomings of the classic markers, we identified a segment of mtDNA that may be used as an 'approximate marker' to closely reproduce the phylogenetic inference obtained from the entire mtDNA in the case of mammalian species, which can be utilized to design amplicon-seq-based studies. Our study demonstrates the importance of the choice of mitochondrial markers for phylogenetic analyses and proposes a novel approach to choosing appropriate markers for mammalian mtDNA that reproduces the phylogenetic inferences obtained from full-length mtDNA.

Evaluation of peripheral blood polymorphonuclear cell functions after an oral carbohydrate overload in obese and insulin dysregulated horses.

Obesity and insulin dysregulation (ID) are increasingly prevalent conditions in equid populations worldwide. Immune impairment is well described in humans with metabolic dysfunction and is reported but still incompletely understood in horses. This study evaluated the effect of acute induced transient hyperglycemia on apoptosis, phagocytosis and oxidative burst activity of peripheral blood polymorphonuclear cells (PMN) of lean and obese adult horses with or without insulin dysregulation. Seventeen adult horses were allocated into three groups based on their body condition score (BCS) and metabolic status: lean-insulin sensitive (lean-IS), obese-insulin sensitive (obese-IS) and obese-insulin dysregulated (obese-ID). ID was determined by insulin tolerance testing (ITT). Blood glucose elevation was induced through an infeed-oral glucose test (in-feed OGT), and all assessments of PMN functions (apoptosis, phagocytosis and oxidative burst) were done in vitro after isolation from peripheral blood before and 120 min after carbohydrate overload. Results were analyzed using a repeated measures linear mixed model with significance defined at P < 0.05. No differences in apoptosis were observed between experimental groups at any time point. Phagocytic capacity was significantly lower at baseline in the obese-ID group but increased in response to glucose administration when compared to the other two groups. Basal reactive oxygen species production in the obese-IS group differed significantly from the lean-IS and obese-ID groups and decreased significantly in response to glucose administration. Results from this study showed that both metabolic status itself, and oral glucose administration, seem to be factors that alter PMN functionality in horses, specifically phagocytosis and oxidative burst.

Adaptive mitochondrial genome functioning in ecologically different farm-impacted natural seedbeds of the endemic blue mussel Mytilus chilensis.

We assessed the adaptive contribution of the mitochondrial genes involved with the respiratory chain and oxidative phosphorylation of the blue mussel Mytilus chilensis, a native and heavily exploited species in the inner sea of Chiloé Island, southern Chile. The assembled mitochondrial transcriptome of individuals from two ecologically different farm-impacted natural seedbeds, Cochamó (41°S) and Yaldad (42°S), represented about 4.5% of the whole de novo transcriptome of the species and showed location and tissue (gills, mantle) specific expression differences in 13 protein-coding mitochondrial genes. The RNA-Seq analysis detected differences in the number of up-regulated mitogenes between individuals from Cochamó (7) and Yaldad (11), some being tissue-specific (ND4L and COX2). However, the analysis did not detect transcripts-per-million (TPM = 0) of ND2 and ND5 in gills and ATP6 in mantle samples from Cochamó. Likewise, for ND6 and ATP8 in any sample. Several monomorphic location-specific mitochondrial genetic variants were detected in samples from Cochamó (78) and Yaldad (207), representing standing genetic variability to optimize mitochondrial functioning under local habitats. Overall, these mitochondrial transcriptomic differences reflect the impact of environmental conditions on the mitochondrial genome functioning and offer new markers to assess the effects on mussel fitness of habitat translocations, a routine industry practice. Likewise, these mitochondrial markers should help monitor and maintain adaptive population differences in this keystone and heavily exploited native species.

A Standardized Procedure for Monitoring Harmful Algal Blooms in Chile by Metabarcoding Analysis.

Harmful algae blooms (HABs) monitoring has been implemented worldwide, and Chile, a country famous for its fisheries and aquaculture, has intensively used microscopic and toxin analyses for decades for this purpose. Molecular biological methods, such as high-throughput DNA sequencing and bacterial assemblage-based approaches, are just beginning to be introduced in Chilean HAB monitoring, and the procedures have not yet been standardized. Here, 16S rRNA and 18S rRNA metabarcoding analyses for monitoring Chilean HABs are introduced stepwise. According to a recent hypothesis, algal-bacterial mutualistic association plays a critical synergetic or antagonistic relationship accounting for bloom initiation, maintenance, and regression. Thus, monitoring HAB from algal-bacterial perspectives may provide a broader understanding of HAB mechanisms and the basis for early warning. Metabarcoding analysis is one of the best suited molecular-based tools for this purpose because it can detect massive algal-bacterial taxonomic information in a sample. The visual procedures of sampling to metabarcoding analysis herein provide specific instructions, aiming to reduce errors and collection of reliable data.

Novel N-Arylsulfonylindoles Targeted as Ligands of the 5-HT6 Receptor. Insights on the Influence of C-5 Substitution on Ligand Affinity.

A new series of twenty-two C-5 substituted N-arylsulfonylindoles was prepared with the aim of exploring the influence of C-5 substitution on 5-HT6 receptor affinity. Eleven compounds showed moderate to high affinity at the receptor (Ki = 58-403 nM), with compound 4d being identified as the most potent ligand. However, regarding C-5 substitution, both methoxy and fluorine were detrimental for receptor affinity compared to our previously published unsubstituted compounds. In order to shed light on these observations, we performed docking and molecular dynamics simulations with the most potent compounds of each series (4d and 4l) and PUC-10, a highly active ligand previously reported by our group. The comparison brings about deeper insight about the influence of the C-5 substitution on the binding mode of the ligands, suggesting that these replacements are detrimental to the affinity due to precluding a ligand from reaching deeper inside the binding site. Additionally, CoMFA/CoMSIA studies were performed to systematize the information of the main structural and physicochemical characteristics of the ligands, which are responsible for their biological activity. The CoMFA and CoMSIA models presented high values of q2 (0.653; 0.692) and r2 (0.879; 0.970), respectively. Although the biological activity of the ligands can be explained in terms of the steric and electronic properties, it depends mainly on the electronic nature.

Charting a course for genetic diversity in the UN Decade of Ocean Science.

The health of the world's oceans is intrinsically linked to the biodiversity of the ecosystems they sustain. The importance of protecting and maintaining ocean biodiversity has been affirmed through the setting of the UN Sustainable Development Goal 14 to conserve and sustainably use the ocean for society's continuing needs. The decade beginning 2021-2030 has additionally been declared as the UN Decade of Ocean Science for Sustainable Development. This program aims to maximize the benefits of ocean science to the management, conservation, and sustainable development of the marine environment by facilitating communication and cooperation at the science-policy interface. A central principle of the program is the conservation of species and ecosystem components of biodiversity. However, a significant omission from the draft version of the Decade of Ocean Science Implementation Plan is the acknowledgment of the importance of monitoring and maintaining genetic biodiversity within species. In this paper, we emphasize the importance of genetic diversity to adaptive capacity, evolutionary potential, community function, and resilience within populations, as well as highlighting some of the major threats to genetic diversity in the marine environment from direct human impacts and the effects of global climate change. We then highlight the significance of ocean genetic diversity to a diverse range of socioeconomic factors in the marine environment, including marine industries, welfare and leisure pursuits, coastal communities, and wider society. Genetic biodiversity in the ocean, and its monitoring and maintenance, is then discussed with respect to its integral role in the successful realization of the 2030 vision for the Decade of Ocean Science. Finally, we suggest how ocean genetic diversity might be better integrated into biodiversity management practices through the continued interaction between environmental managers and scientists, as well as through key leverage points in industry requirements for Blue Capital financing and social responsibility.

Adaptive Differences in Gene Expression in Farm-Impacted Seedbeds of the Native Blue Mussel Mytilus chilensis.

The study of adaptive population differences is relevant for evolutionary biology, as it evidences the power of selective local forces relative to gene flow in maintaining adaptive phenotypes and their underlying genetic determinants. However, human-mediated hybridization through habitat translocations, a common and recurrent aquaculture practice where hybrids could eventually replace local genotypes, risk populations' ability to cope with perturbations. The endemic marine mussel Mytilus chilensis supports a booming farming industry in the inner sea of Chiloé Island, southern Chile, which entirely relies on artificially collected seeds from natural beds that are translocated to ecologically different fattening centers. A matter of concern is how farm-impacted seedbeds will potentially cope with environmental shifts and anthropogenic perturbations. This study provides the first de novo transcriptome of M. chilensis; assembled from tissue samples of mantles and gills of individuals collected in ecologically different farm-impacted seedbeds, Cochamó (41°S) and Yaldad (43°S). Both locations and tissue samples differentially expressed transcripts (DETs) in candidate adaptive genes controlling multiple fitness traits, involved with metabolism, genetic and environmental information processing, and cellular processes. From 189,743 consensus contigs assembled: 1,716 (Bonferroni p value ≤ 0.05) were DETs detected in different tissues of samples from different locations, 210 of them (fold change ≥ | 100|) in the same tissue of samples from a different location, and 665 (fold change ≥ | 4|) regardless of the tissue in samples from a different location. Site-specific DETs in Cochamó (169) and Yaldad (150) in candidate genes controlling tolerance to temperature and salinity shifts, and biomineralization exhibit a high number of nucleotide genetic variants with regular occurrence (frequency > 99%). This novel M. chilensis transcriptome should help assessing and monitoring the impact of translocations in wild and farm-impacted mussel beds in Chiloé Island. At the same time, it would help designing effective managing practices for conservation, and translocation traceability.

Molecular and physiological analysis of indole-3-acetic acid degradation in Bradyrhizobium japonicum E109.

Bradyrhizobium japonicum E109 is a bacterium widely used for inoculants production in Argentina. It is known for its ability to produce several phytohormones and degrade indole-3-acetic acid (IAA). The genome sequence of B. japonicum E109 was recently analyzed and it showed the presence of genes related to the synthesis of IAA by indole-3-acetonitrile, indole-3-acetamide and tryptamine pathways. Nevertheless, B. japonicum E109 is not able to produce IAA and instead has the ability to degrade this hormone under saprophytic culture conditions. This work aimed to study the molecular and physiological features of IAA degradation and identify the genes responsible of this activity. In B. japonicum E109 we identified two sequences coding for a putative 3-phenylpropionate dioxygenase (subunits α and ß) responsible for the IAA degradation that were homologous to the canonical cluster of iacC and iacD of Pseudomonas putida 1290. These genes form a separate cluster together with three additional genes with unknown functions. The degradation activity was found to be constitutively expressed in B. japonicum E109. As products of IAA degradation, we identified two compounds, 3-indoleacetic acid 2,3-oxide and 2-(2-hydroperoxy-3-hydroxyindolin-3-yl) acetic acid. Our report proposes, for the first time, a model for IAA degradation in Bradyrhizobium.

Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea)

BACKGROUND: Vibrio species display variable and plastic fitness strategies to survive and interact with multiple hosts, including marine aquaculture species that are severely affected by pathogenic Vibrios. The culturable Vibrio sp. strain ArtGut-C1, the focus of this study, provides new evidence of such phenotypic plasticity as it accumulates polyhydroxybutyrate (PHB), a biodegradable polymer with anti-pathogen activity, particularly in the marine larviculture phase. The strain was isolated from the gut of laboratory-reared Artemia individuals, the live diet and PHB carrier used in larviculture. Its main phenotypic properties, taxonomic status and genomic properties are reported based on the whole-genome sequencing. RESULTS: Vibrio sp. ArtGut-C1 yielded 72.6% PHB of cells' dry weight at 25 C. The genomic average nucleotide identity (ANI) shows it is closely related to V. diabolicus (ANI: 88.6%). Its genome contains 5,236,997- bp with 44.8% GC content, 3,710 protein-coding sequences, 96 RNA, 9 PHB genes functionally related to PHB metabolic pathways, and several genes linked to competing and colonizing abilities. CONCLUSIONS: This culturable PHB-accumulating Vibrio strain shows high genomic and phenotypic variability. It may be used as a natural pathogen biocontrol in the marine hatchery and as a potential cell factory for PHB production.

Suitcase Lab: new, portable, and deployable equipment for rapid detection of specific harmful algae in Chilean coastal waters.

Phytoplankton blooms, including harmful algal blooms (HABs), have serious impacts on ecosystems, public health, and productivity activities. Rapid detection and monitoring of marine microalgae are important in predicting and managing HABs. We developed a toolkit, the Suitcase Lab, to detect harmful algae species in the field. We demonstrated the Suitcase Lab's capabilities for sampling, filtration, DNA extraction, and loop-mediated isothermal amplification (LAMP) detection in cultured Alexandrium catenella cells as well as Chilean coastal waters from four sites: Repollal, Isla García, Puerto Montt, and Metri. A LAMP assay using the Suitcase Lab in the field confirmed microscopic observations of A. catenella in samples from Repollal and Isla García. The Suitcase Lab allowed the rapid detection of A. catenella, within 2 h from the time of sampling, even at a single cell per milliliter concentrations, demonstrating its usefulness for quick and qualitative on-site diagnosis of target toxic algae species. This method is applicable not only to detecting harmful algae but also to other field studies that seek a rapid molecular diagnostic test.

Protocols for Monitoring Harmful Algal Blooms for Sustainable Aquaculture and Coastal Fisheries in Chile.

Harmful algae blooms (HABs) cause acute effects on marine ecosystems due to their production of endogenous toxins or their enormous biomass, leading to significant impacts on local economies and public health. Although HAB monitoring has been intensively performed at spatiotemporal scales in coastal areas of the world over the last decades, procedures have not yet been standardized. HAB monitoring procedures are complicated and consist of many methodologies, including physical, chemical, and biological water sample measurements. Each monitoring program currently uses different combinations of methodologies depending on site specific purposes, and many prior programs refer to the procedures in quotations. HAB monitoring programs in Chile have adopted the traditional microscopic and toxin analyses but not molecular biology and bacterial assemblage approaches. Here we select and optimize the HAB monitoring methodologies suitable for Chilean geography, emphasizing on metabarcoding analyses accompanied by the classical tools with considerations including cost, materials and instrument availability, and easiness and efficiency of performance. We present results from a pilot study using the standardized stepwise protocols, demonstrating feasibility and plausibility for sampling and analysis for the HAB monitoring. Such specific instructions in the standardized protocol are critical obtaining quality data under various research environments involving multiple stations, different analysts, various time-points, and long HAB monitoring duration.

Semen quality and freezability analysis during breeding and non-breeding seasons in heavy draft stallions in southern Chile.

The aim of this study was to evaluate seasonal changes in basic parameters of sperm quality and freezability behaviour of ejaculates from 10 fertile heavy draft stallions. A total of 140 ejaculates were collected, processed and evaluated during both the breeding (September-November) and non-breeding seasons (April-June). Fresh semen was evaluated for volume, concentration, total spermatozoa per ejaculate, plasma membrane integrity and total sperm motility. Cryopreserved samples were evaluated for plasma membrane integrity and sperm motility by the CASA system, and for the freezability index (FI), which was defined as the decreased ratio of viability after freezing-thawing. In fresh ejaculates, only viability showed significantly higher values in the breeding than in the non-breeding season (64.0% ± 15.0% vs. 58.6% ± 12.0%, respectively; p < .05). The sperm post-thawing analysis of viability and total motility parameters showed no significant changes linked to the season. However, the FI analysis showed that the ejaculates collected in the non-breeding season had higher cryoresistance characteristics than those collected in the breeding season. Results suggest that the presence of some cryoprotective factor/s in heavy draft horse ejaculates could be modulated by seasonality, with higher protective effects in the non-breeding season.

Exploring parasites in extreme environments of high conservational importance: Artemia franciscana (Crustacea: Branchiopoda) as intermediate host of avian cestodes in Andean hypersaline lagoons from Salar de Atacama, Chile.

The hypersaline lagoons located in evaporation basins or salars (salt flats) in the Atacama Desert are extreme environments harbouring a specialised biota able to survive harsh conditions for life. The knowledge of the parasitic biodiversity of these extreme habitats is still scarce despite their functional importance in regulating relevant non-economic services like habitats of waterbirds. The present study is the first report on the cestode infection of Artemia franciscana Kellogg in Salar de Atacama lagoons in northern Chile. A total of 23 parasite larvae were isolated and identified as belonging to five cestode taxa of the order Cyclophyllidea: two species of the family Hymenolepididae, i.e. Flamingolepis sp. 1 and Flamingolepis sp. 2 (adults parasitic in flamingos); two species of Dilepididae, i.e. Fuhrmannolepis averini (adults parasitic in phalaropes) and Eurycestus avoceti (adult parasitic in charadriforms birds); and one species of Progynotaeniidae, i.e. Gynandrotaenia (?) stammeri (adult parasitic in flamingos). The cysticercoids of each species are described and figured. The study represents the first geographical record of the genera Eurycestus, Gynandrotaenia and Fuhrmannolepis in South America and the first report of Gynandrotaenia and Flamingolepis in A. franciscana in its native range. This survey also contributes to the knowledge of cestodes of Phoenicopteriformes and Charadriiformes and their life cycles in the Neotropical Region. A review of cestodes recorded in brine shrimps of the genus Artemia in the world is provided. Further studies on cestode fauna of aquatic birds and their intermediate hosts in hypersaline habitats of the Neotropical Region are needed to understand their functional role in such extreme and unique ecosystems.

Pre-conditioning of Equine Bone Marrow-Derived Mesenchymal Stromal Cells Increases Their Immunomodulatory Capacity.

Mesenchymal stem/stromal cells (MSCs) are increasingly explored for the treatment of degenerative and inflammatory diseases in human and veterinary medicine. One of the key characteristics of MSCs is that they modulate inflammation mainly through the secretion of soluble mediators. However, despite widespread clinical use, knowledge regarding the effector mechanisms of equine MSCs, and consequently their effectiveness in the treatment of diseases, is still unknown. The objectives of this study were to determine the mechanisms underlying inhibition of lymphocyte proliferation by equine bone marrow-derived MSCs, and to evaluate the effect of pre-conditioning of equine MSCs with different pro-inflammatory cytokines on inhibition of lymphocyte proliferation. We determined that inhibition of lymphocyte proliferation by equine MSCs depends on activity of prostaglandin-endoperoxide synthase 2 and indoleamine 2,3-dioxygenase. Additionally, pre-conditioning of MSCs with TNF-α, IFN-γ or their combination significantly increased the expression of prostaglandin-endoperoxide synthase 2, indoleamine 2,3-dioxygenase, iNOS and IL-6. This upregulation correlated with an increased inhibitory effect of MSCs on lymphocyte proliferation. In conclusion, pre-conditioning of bone marrow-derived MSC increases their inhibitory effect on lymphocyte proliferation in horses.

Assessment of peripheral blood neutrophil respiratory burst, phagocytosis and apoptosis in obese non-insulin dysregulated horses.

Obesity is a highly prevalent condition in horses. Dysfunctional neutrophil activity has been reported in metabolically healthy obese humans, but minimal data exist regarding horses. The present study evaluated the effect of obesity on apoptosis, phagocytosis and oxidative burst activity of peripheral blood neutrophils from lean and obese non-insulin dysregulated horses. Seven lean (BCS, body condition score 4-6/9) and five obese (BCS 8-9) horses were enrolled in the study. All animals underwent two metabolic tests (OGT, oral glucose test; IRT, insulin response test) before their selection to ensure their metabolic status (non-insulin dysregulated). A single blood sample was obtained from each horse, and a discontinuous density gradient was carried out to isolate neutrophils. Phagocytosis, apoptosis and reactive oxygen species (ROS) production assays were performed for each animal. All statistical analyses were performed with unpaired two-tailed t-tests. Results indicate that neutrophils from obese non-insulin dysregulated horses have a significantly increased ROS production (P < .0001), with no changes observed on phagocytosis (P > .05) or apoptosis (P > .05) when compared to the control group. In conclusion, our results demonstrate that obesity per se, in absence of other endocrine disorders, alters neutrophil reactive oxygen species production. More research is needed to understand the role of obesity on the equine immune system of horses, and its role in the development of endocrine disorders.