Universal model for the skin colouration patterns of neotropical catfishes of the genus Pseudoplatystoma

Fish skin colouration has been widely studied because it involves a variety of processes that are important to the broad field of the developmental biology. Mathematical modelling of fish skin patterning first predicted the existence of morphogens and helped to elucidate the mechanisms of pattern formation. The catfishes of the genus Pseudoplatystoma offer a good biological study model, since its species exhibit the most spectacular and amazing variations of colour patterns on the skin. They present labyrinths, closed loops (or cells), alternate spots and stripes, only spots and combinations of these. We have extended a well known mathematical model to study the skin of Pseudoplatystoma. The basic model is a two component, non-linear reaction diffusion system that presents a richness of bifurcations. The extended model assumes that there are two interacting cell/tissue layers in which morphogens diffuse and interact giving rise to the skin colouration pattern. We have found that by varying only two parameters we are able to accurately reproduce the distinct patterns found in all species of Pseudoplatystoma. The histological analysis of skin samples of two species of this genus, with different patterns, revealed differences on the disposition of the colouration cells that are consistent with our theoretical predictions.Fil: Scarabotti, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Govezensky, Tzipe. Universidad Nacional Autónoma de México; MéxicoFil: Bolcatto, Pablo Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Barrio, Rafael Ángel. Universidad Nacional Autónoma de México; Méxic

Gene regulatory factors in the evolutionary history of humans: Gene Regulatory Factors, key genes in the evolutionary history of modern humans: Positive selection on GRF genes as source for regulatory diversity in human populations: Human lineage‐specific transcriptional regulation through GA binding protein transcription factor alpha (GABPa)

Changes in cis- and trans-regulatory elements are among the prime sources of genetic and phenotypical variation at species level. The introduction of cis- and trans- regulatory variation has played important roles in driving diversity, phenotypical differentiation, and evolution of humans. Therefore, variation that occurs on cis- and trans- regulatory elements becomes imperative to better understanding of human genetic diversity and its evolution. In this research, around 3360 gene regulatory factors (GRF) from the human genome were catalogued. This catalog includes genes that code for proteins that perform gene regulatory activities such DNA-depending transcription, RNA polymerase II transcription cofactor and co-repressor activity, chromatin binding and remodeling, among other 218 regulatory functions. This GRF catalog allowed us to initially explore how some GRF genes have evolved in humans, archaic humans (Neandertal and Denisovan) and non-human primate species. We discussed the likely phenotypical and medical effects that evolutionary changes in GRF genes may have introduced into the human genome; for instance, traits associated to speech and language capabilities, genomic recombination hotspots, diseases, among others. By using genome-wide datasets, we additionally looked for GRFs likely to be candidates for positive selection in three human populations: Utah Residents with Northern and Western Ancestry (CEU), Han Chinese in Beijing (CHB), and Yoruba in Ibadan (YRI). As result, we produced a set of candidates that gathers genes that may have contributed in shaping the phenotypical diversity currently observed in these populations; for instance, by introducing regulatory diversity at population-specific level. We additionally identified six GRF classes enriched for genes located in regions that are likely candidates for positive selection at population specific level. We found that out of the 41 DNA-binding GRF classes classified so far, six groups exhibited enrichment for genes located on regions that may have been under positive selection: C2H2 zinc finger, KRAB-ZNF zinc finger, Homeo domain, Tryptophan cluster, Fork head/winged helix and, and High-mobility HMG domain. We additionally identified three KRAB-ZNF gene clusters, in the chromosomes one, three, and 16, for the Asian population that exhibit regions with extended haplotype homozygosity EHH (larger than 100 kb). This EHH suggests that these regions have undergone positive selection in CHB population. Finally, considering that a representative fraction of the phenotypic diversity observed between humans and its closely related species are likely explained by changes in cis-regulatory elements (CREs), we investigated putative binding sites for the transcription factor GABPa. Using ChIP-Seq data generated from a human cell line (HEK293T), 11,619 putative GABPa CREs were found, Out of which 224 are putative human-specific. To experimentally validate the transcriptional activity of these human-specific CREs, reporter gene essays and knock-down experiments were performed. Our results supported the functionality of these human-specific GABPa CREs and suggest that at least 1,215 genes are primary targets of GABPa. Finally, further analyses depict scenarios that put together transcriptional regulation by GABPa and the evolution of particular human traits; for instance, cognitive abilities, breast morphology, lipids and glucose metabolic pathways, among others

Efecto de la temperatura en el colágeno presente en espinas intramusculares de filetes de bocachico (prochilodus magdalenae) sobre las características de textura y microestructurales

El bocachico es el nombre común del pez Prochilodus sp. nativo de las cuencas hidrográficas de varios países suramericanos. En Colombia hace parte de los peces dedicados a la piscicultura y aunque no es alta la producción, es un pez que se destaca en el consumo tradicional. La presencia de espinas intramusculares ha impedido que sean comercializados los filetes del bocachico, sin embargo el desarrollo de nuevas tecnologías ha permitido la posibilidad de obtener filetes de esta especie. Los cortes en las espinas intramusculares permiten exponer los componentes internos de la espina. En este sentido es necesario determinar la clase de colágeno asociado a las espinas intramusculares y el efecto que puede tener los procesos térmicos sobre la degradación del colágeno, para permitir la obtención de filetes de esta especie. La aplicación de procesos físicos en la espina intramuscular antes del tratamiento térmico podría ser una alternativa en la degradación de estas espinas. El objetivo de este trabajo fue analizar microestructuralmente los componentes que pueden ser afectados según la duración del proceso térmico. Las espinas intramusculares de filetes de bocachico fueron analizadas a través de electroforesis en gel de SDS-poliacrilamida (SDS-PAGE), temperatura de desnaturalización del colágeno, microscopia electrónica de trasmisión y fuerza de corte, sometidas a tres tiempos de duración del tratamiento térmico (1.5; 2 y 3 min). Los resultados indican que el colágeno presente en espinas intramusculares es tipo l. el tratamiento térmico que consiguió la mayor degradación del colágeno fueron tres minutos, coincidiendo con los valores menores para la prueba de fuerza de corte. Los resultados permiten concluir que la degradación del colágeno es iniciada desde el interior de las espinas intramusculares hacia la capa externa, sin que esta última se vea afectada por el tratamiento térmico.Abstract. The “bocachico” is the common name of fish Prochilodus sp. native watersheds of several South American countries. In Colombia is part dedicated to fish farming and although not high production is a fish that stands out in the traditional consumption. The presence of intramuscular bones are marketed has prevented bocachico fillet, but the development of new technologies has enabled the possibility of this species fillets. The cuts allow intramuscular bones expose the internal components of pin bones. In this sense it is necessary to determine the type of collagen associated with intramuscular bones and the effect it can have thermal processes on the degradation of collagen, to allow obtaining this species fillets. The application of physical processes in the pin bones intramuscular before heat treatment could be an alternative in the degradation of these spines. The aim of this study was to analyze microstructural components that may be affected by the duration of the thermal process. Intramuscular bone bocachico fillets were analyzed by electrophoresis on SDS-polyacrylamide gel (SDS-PAGE), the collagen denaturation temperature, and transmission electron microscopy strength force, subjected to three times of duration of heat treatment (1.5, 2 and 3 min). The results indicate that intramuscular bone collagen is present in type l. thermal treatment achieved greater collagen degradation were three minutes, coinciding with the lowest values for shear strength test. The results show that collagen degradation is initiated from inside intramuscular bone to the outer layer, although this shows effect of heat treatment.Maestrí

Sewage

Wastewater treatment is crucial for human development. The current state of development of wastewater, the current state of its impact, and the current state of development of wastewater treatment methods are to be closely followed. This book compiles some of the cutting-edge developments related to wastewater treatment