Adaptive genetic variation distinguishes Chilean blue mussels (Mytilus chilensis) from different marine environments

Chilean mussel populations have been thought to be panmictic with limited genetic structure. Genotyping-by-sequencing approaches have enabled investigation of genomewide variation that may better distinguish populations that have evolved in different environments. We investigated neutral and adaptive genetic variation in Mytilus from six locations in southern Chile with 1240 SNPs obtained with RAD-seq. Differentiation among locations with 891 neutral SNPs was low (F-ST = 0.005). Higher differentiation was obtained with a panel of 58 putative outlier SNPs (F-ST = 0.114) indicating the potential for local adaptation. This panel identified clusters of genetically related individuals and demonstrated that much of the differentiation (similar to 92%) could be attributed to the three major regions and environments: extreme conditions in Patagonia, inner bay influenced by aquaculture (Reloncavi), and outer bay (Chiloe Island). Patagonia samples were most distinct, but additional analysis carried out excluding this collection also revealed adaptive divergence between inner and outer bay samples. The four locations within Reloncavi area were most similar with all panels of markers, likely due to similar environments, high gene flow by aquaculture practices, and low geographical distance. Our results and the SNP markers developed will be a powerful tool supporting management and programs of this harvested species.CONICYT FONDECYT 113030

Salmonids

The modern salmon industry has had an explosive growth rate since the 1980s (Dunham et al. 2001), especially in Norway and the United Kingdom. Salmon and trout production requires cold waters with high oxygen content and low levels of pollutants, with a preference for protected coastal sectors far from big urban centers. So, even though cultured salmonid species originated in the Northern Hemisphere, close to 40% of the salmon produced in captivity today comes from the Southern Hemisphere, where they have been successfully introduced and cultivated

Sex hormone binding globulin b expression in the rainbow trout ovary prior to sex differentiation

Salmonids have two sex hormone-binding globulin (Shbg) paralogs. Shbga is mainly expressed in the liver, while Shbgb is secreted by the granulosa cells of the rainbow trout ovary. Coexpression of shbgb and the gonadal aromatase cyp19a1a mRNAs been observed in granulosa cells, suggesting a physiological coordination between Shbgb expression and estrogen synthesis. As estrogens are essential for female sex determination in the fish ovary, we propose that Shbgb participates in early ovarian differentiation, either by binding with estrogen or through another mechanism that remains to be discovered. To elucidate this potential role, monosex populations of female trout were studied during the molecular ovarian differentiation period (28-56 dpf). shbgb mRNA expression was measured using qPCR and compared with expression of genes for other ovarian markers (cyp19a1a, fox12, follistatin, and estrogen receptors). shbgb transcript expression was detected during the final stages of embryonic development (21-26 dpf) and during molecular ovarian differentiation (32-52 dpf) after hatching (which occurred at 31 dpf). In situ hybridization localized shbgb transcription to the undifferentiated ovary at 42 dpf, and shbgb and cyp19a1a mRNA showed similar expression patterns. These results suggest that Shbgb is involved in early ovarian differentiation, supporting an important role for the salmonid shbgb gene in sex determination.CONICYT from the Chilean government Facultad de Ciencias, Universidad de la Republica, Urugua

Native and invasive taxa on the Pacific coast of South America: Impacts on aquaculture, traceability and biodiversity of blue mussels (Mytilus spp.)

Gaining new knowledge of the native distributions of species (phylogeography) is more and more difficult in a world affected by anthropogenic disturbance, in particular by species translocations. Increasingly, molecular markers are required to support de-cisions about the taxonomy of native vs. introduced species, and the existence of their hybrids, to answer phylogeographic questions. In many fields, including aquaculture, traceability and food security, taxonomic and phylogeographic knowledge is key to the successful management and conservation of biodiversity. The Pacific coast of Chile is one of the last regions without a clear and agreed understanding of the taxonomy and systematics of smooth- shelled blue mussels of the genus Mytilus. A panel of 49 bi- allelic single nucleotide polymorphisms (SNPs) was genotyped in 338 Mytilus individu-als collected from nine Chilean and five reference populations. All analyses confirmed the hypothesis that the native Chilean blue mussel is genetically distinct from the ref-erence species M. edulis, M. galloprovincialis and M. trossulus. These results support the hypothesis of a unique evolutionary history of the native Chilean blue mussel on the Pacific coast of South America. It is therefore concluded that the native blue mussel from Chile should be recognized as M. chilensis Hupé 1854. We confirmed a recent Mediterranean origin of introduced M. galloprovincialis on the coast of Chile. This knowledge advances the understanding of global phylogeography of blue mussels and their bioinvasions and harmonizes taxonomy in the context of aquaculture production, seafood traceability, labelling and trade.Fondo de Fomento al Desarrollo Científico y Tecnológico, Grant/Award Number: IDeAID16I10013 and N°1130302; Narodowe Centrum Nauki, Grant/Award Number: 2011/01/B/NZ9/0435

Educación y aprendizajes en tiempos del COVID19

La pandemia del COVID19 impactó en todos los aspectos de la vida de los seres humanos y la educación es uno de esos aspectos. Investigadoras e investigadores de diferentes países de habla hispana que hacemos docencia nos preguntamos ¿cómo impactó en educación? ¿cómo afrontaron las partes de la díada educativa el cambio de modalidad educativa? ¿cómo se observa desde ambos lados? Presentamos los primeros resultados, ideas preliminares y preguntas que nos empiezan a plantear los resultados.Fil: Castañeda Sortibran, América Nitxin. Universidad Nacional Autónoma de México; MéxicoFil: Araneda Tolosa, Cristian. Universidad de Chile; ChileFil: Peschi, Samanta. Universidad de Valencia; EspañaFil: Calaforra, Luis Pascual. Universidad Católica de La Plata; ArgentinaFil: Rodríguez Gil, Sergio Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaCONICET La Plata frente a la Pandemia COVID-19La PlataArgentinaCentro de Estudios Parasitológicos y de VectoresUniversidad de ChileUniversidad Católica de La PlataUniversidad de Valenci