Whole-genome sequencing reveals insights into the adaptation of French Charolais cattle to Cuban tropical conditions

In the early 20th century, Cuban farmers imported Charolais cattle (CHFR) directly from France. These animals are now known as Chacuba (CHCU) and have become adapted to the rough environmental tropical conditions in Cuba. These conditions include long periods of drought and food shortage with extreme temperatures that European taurine cattle have difficulty coping with. In this study, we used whole-genome sequence data from 12 CHCU individuals together with 60 whole-genome sequences from six additional taurine, indicus and crossed breeds to estimate the genetic diversity, structure and accurate ancestral origin of the CHCU animals. Although CHCU animals are assumed to form a closed population, the results of our admixture analysis indicate a limited introgression of Bos indicus. We used the extended haplotype homozygosity (EHH) approach to identify regions in the genome that may have had an important role in the adaptation of CHCU to tropical conditions. Putative selection events occurred in genomic regions with a high proportion of Bos indicus, but they were not sufficient to explain adaptation of CHCU to tropical conditions by Bos indicus introgression only. EHH suggested signals of potential adaptation in genomic windows that include genes of taurine origin involved in thermogenesis (ATP9A, GABBR1, PGR, PTPN1 and UCP1) and hair development (CCHCR1 and CDSN). Within these genes, we identified single nucleotide polymorphisms (SNPs) that may have a functional impact and contribute to some of the observed phenotypic differences between CHCU and CHFR animals. Whole-genome data confirm that CHCU cattle are closely related to Charolais from France (CHFR) and Canada, but also reveal a limited introgression of Bos indicus genes in CHCU. We observed possible signals of recent adaptation to tropical conditions between CHCU and CHFR founder populations, which were largely independent of the Bos indicus introgression. Finally, we report candidate genes and variants that may have a functional impact and explain some of the phenotypic differences observed between CHCU and CHFR cattle

Whole-genome sequencing reveals insights into the adaptation of French Charolais cattle to Cuban tropical conditions

Background: In the early 20th century, Cuban farmers imported Charolais cattle (CHFR) directly from France. These animals are now known as Chacuba (CHCU) and have become adapted to the rough environmental tropical condi‑ tions in Cuba. These conditions include long periods of drought and food shortage with extreme temperatures that European taurine cattle have difculty coping with. Results: In this study, we used whole-genome sequence data from 12 CHCU individuals together with 60 wholegenome sequences from six additional taurine, indicus and crossed breeds to estimate the genetic diversity, structure and accurate ancestral origin of the CHCU animals. Although CHCU animals are assumed to form a closed population, the results of our admixture analysis indicate a limited introgression of Bos indicus. We used the extended haplotype homozygosity (EHH) approach to identify regions in the genome that may have had an important role in the adapta‑ tion of CHCU to tropical conditions. Putative selection events occurred in genomic regions with a high proportion of Bos indicus, but they were not sufcient to explain adaptation of CHCU to tropical conditions by Bos indicus introgres‑ sion only. EHH suggested signals of potential adaptation in genomic windows that include genes of taurine origin involved in thermogenesis (ATP9A, GABBR1, PGR, PTPN1 and UCP1) and hair development (CCHCR1 and CDSN). Within these genes, we identifed single nucleotide polymorphisms (SNPs) that may have a functional impact and contribute to some of the observed phenotypic diferences between CHCU and CHFR animals. Conclusions: Whole-genome data confrm that CHCU cattle are closely related to Charolais from France (CHFR) and Canada, but also reveal a limited introgression of Bos indicus genes in CHCU. We observed possible signals of recent adaptation to tropical conditions between CHCU and CHFR founder populations, which were largely independent of the Bos indicus introgression. Finally, we report candidate genes and variants that may have a functional impact and explain some of the phenotypic diferences observed between CHCU and CHFR cattle.info:eu-repo/semantics/publishedVersio

Effect of domestication in the pig genome

Departament responsable de la tesi: Departament de Genètica i de Microbiologia.La domesticación animal es un proceso realmente importante en la historia del hombre en el cual se seleccionaron diferentes rasgos de interés de los animales, como puede ser un crecimiento más rápido o una mayor docilidad. Para estudiar la domesticación a nivel genético es necesario identificar una serie de marcadores relacionados con este proceso evolutivo. Los avances en las tecnologías de secuenciación han mejorado considerablemente la investigación de la genómica de la domesticación, pudiendo determinar los cambios genéticos que causan esa transformación de especie salvaje a doméstica. El objetivo principal de esta tesis es la evaluación del efecto de la domesticación en el genoma del cerdo mediante el análisis de la diversidad genética en poblaciones domésticas y salvajes. En la primera parte se ha realizado un análisis de la diferenciación y del desequilibrio de ligamiento para detectar las diferencias entre cerdos domésticos y salvajes, utilizando la vía metabólica como unidad de análisis. Mediante el estudio de la diferenciación, utilizando el estadístico Fst, obtenemos una serie de rutas significativas relacionadas con el comportamiento y el desarrollo, que fueron algunos de los primeros rasgos seleccionados en cerdo. Sin embargo, al realizar el análisis del desequilibrio, mediante el estadístico nSL, detectamos diferencias en rutas relacionadas con la reproducción del animal, rasgo seleccionado recientemente. Por otro lado, realizamos una red de co-asociación entre todas las vías metabólicas significativamente diferentes entre cerdos domésticos y salvajes, obteniendo 3 clústeres diferenciados, uno relacionado con el crecimiento y la regulación hormonal, otro con el sistema nervioso simpático y el último con la reproducción. En la segunda parte, realizamos un análisis de la fuerza de la selección a nivel genómico en cerdos domésticos y salvajes, utilizando dos poblaciones domésticas, Ibérico y Large White, las cuales son muy diferentes entre ellas. Mientras que Ibérico es una raza autóctona que ha sufrido recientemente una gran reducción del tamaño poblacional, Large White es una raza comercial internacional que ha sido mejorada de manera artificial, además de introgresada con cerdos asiáticos. Para analizar la fuerza de la selección utilizamos el parámetro α, que estima la proporción de sustituciones no-sinónimas que son adaptativas, utilizando cuatro estimadores diferentes de la variabilidad, cada uno enfocado a una parte del espectro de frecuencias: Fu&Li (solo singletons), Watterson (todo el espectro dando más peso a las bajas frecuencias), Tajima (todo el espectro de manera uniforme) y Fay&Wu (incrementa el peso de manera proporcional a la frecuencia). Sin embargo, al analizar los patrones de selección no encontramos más señales comunes entre las razas domesticadas que al compararlas con la salvaje. En cambio, encontramos un mayor efecto de la demografía en la selección, Ibérico tiene una variabilidad muy baja debido a su bajo tamaño poblacional, lo cual se muestra en los patrones de selección obtenidos, que se asemejan a una reducción poblacional; mientras que Large White tiene una mayor variabilidad debido posiblemente a la presencia de alelos asiáticos en su genoma, obteniendo patrones explicados por la presencia tanto de mutaciones deletéreas como beneficiosas, además de una expansión poblacional y/o migración.Por último, hemos desarrollado una aplicación web para poder analizar archivos VCF, la cual puede ayudarnos a identificar posibles errores o sesgos, principalmente relacionados con la cobertura del SNP.Animal domestication is an important process in the human history in which different traits of the animals were selected, such as faster growth or greater docility. To study domestication at the genetic level it is necessary to identify the markers related to this evolutionary process. Advances in sequencing technologies have improved the investigation of the genomics of domestication, which has allowed to determine the genetic changes that cause this transformation from wild to domestic species. The main goal of this thesis is the evaluation of the domestication effect in the pig genome through the analysis of genetic diversity in domestic and wild populations. In the first part, analyses of differentiation and linkage disequilibrium were performed to detect differences between domestic and wild pigs, using the pathway as the unit of analysis. Through the study of differentiation, using the Fst statistic, we obtained significant pathways related to behavior and development, which were some of the first selected traits in pigs. On the other hand, when performing the disequilibrium analysis, using the nSL statistic, we detected differences in pathways related to the reproduction of the animal, a recently selected trait. Besides, we made a co-association network using all pathways that are significantly different between domestic and wild pigs, obtaining three differentiated clusters, one related to growth and hormonal regulation, another with the sympathetic nervous system and the last with the reproduction. In the second part, we performed an analysis of the strength of selection at the genome level in domestic and wild pigs, using two very different domestic populations, Iberian and Large White. Iberian breed is an autochthonous breed that has recently suffered a strong reduction in the effective population size, Large White is an international commercial breed that has been artificially improved and introgressed with Asian pigs. To analyze the strength of the selection we use the parameter α, which estimates the proportion of non-synonymous substitutions that are adaptive, using four different estimators of variability, each focused on a part of the frequency spectrum: Fu&Li (only singletons), Watterson (whole spectrum giving more weight at low frequencies), Tajima (whole spectrum weighted uniformly) and Fay&Wu (increases the weight proportionally with the frequency). However, when analyzing the selection patterns, we did not find more common signals between the two domestic breeds than between domestic and wild ones. Instead, we found a larger effect of demography on the selection, Iberian has a very low variability due to its low population size, which is shown in the obtained selection patterns, which resemble a population reduction; while Large White has a larger variability, possibly due to the presence of Asian alleles in its genome, obtaining patterns that can be explained by the presence of both deleterious and beneficial mutations, together with a population expansion and/or migration. Finally, we have developed a web-based application to analyze VCF files, which can help identify possible errors or biases, mainly related to the SNP coverage

A pathway-centered analysis of pig domestication and breeding in eurasia

Ascertaining the molecular and physiological basis of domestication and breeding is an active area of research. Due to the current wide distribution of its wild ancestor, the wild boar, the pig (Sus scrofa) is an excellent model to study these processes, which occurred independently in East Asia and Europe ca. 9,000 years ago. Analyzing genome variability patterns in terms of metabolic pathways is attractive since it considers the impact of interrelated functions of genes, in contrast to genome-wide scans that treat genes or genome-windows in isolation. To that end, we studied 40 wild boars and 123 domestic pig genomes from Asia and Europe when metabolic pathway was the unit of analysis. We computed statistical significance for differentiation (Fst) and linkage disequilibrium (nSL) statistics at the pathway level. In terms of Fst, we found 21 and 12 pathways significantly differentiated at a q-value < 0.05 in Asia and Europe, respectively; five were shared across continents. In Asia, we found six significant pathways related to behavior, which involved essential neurotransmitters like dopamine and serotonin. Several significant pathways were interrelated, and shared a variable percentage of genes. There were 12 genes present in more than 10 significant pathways (in terms of Fst), comprising genes involved in the transduction of a large number of signals, like phospholipase PCLB1, which is expressed in the brain, or ITPR3, which has an important role in taste transduction. In terms of nSL, significant pathways were mainly related to reproductive performance (ovarian steroidogenesis), an important target trait as well during domestication and modern animal breeding. Different levels of recombination cannot explain these results, since we found no correlation between Fst and recombination rate. However, we did find an increased ratio of deleterious mutations in domestic vs. wild populations, suggesting a relaxed functional constraint associated with the domestication and breeding processes. Purifying selection was, nevertheless, stronger in significantly differentiated pathways than in random pathways, mainly in Europe. We conclude that pathway analysis facilitates the biological interpretation of genome-wide studies. Notably in the case of pig, behavior played an important role, among other physiological and developmental processes

A pathway-centered analysis of pig domestication and breeding in Eurasia

Ascertaining the molecular and physiological basis of domestication and breeding is an active area of research. Due to the current wide distribution of its wild ancestor, the wild boar, the pig (Sus scrofa) is an excellent model to study these processes, which occurred independently in East Asia and Europe ca. 9000 yr ago. Analyzing genome variability patterns in terms of metabolic pathways is attractive since it considers the impact of interrelated functions of genes, in contrast to genome-wide scans that treat genes or genome windows in isolation. To that end, we studied 40 wild boars and 123 domestic pig genomes from Asia and Europe when metabolic pathway was the unit of analysis. We computed statistical significance for differentiation (Fst) and linkage disequilibrium (nSL) statistics at the pathway level. In terms of Fst, we found 21 and 12 pathways significantly differentiated at a q -value 10 significant pathways (in terms of Fst), comprising genes involved in the transduction of a large number of signals, like phospholipase PCLB1, which is expressed in the brain, or ITPR3, which has an important role in taste transduction. In terms of nSL, significant pathways were mainly related to reproductive performance (ovarian steroidogenesis), a similarly important target trait during domestication and modern animal breeding. Different levels of recombination cannot explain these results, since we found no correlation between Fst and recombination rate. However, we did find an increased ratio of deleterious mutations in domestic vs. wild populations, suggesting a relaxed functional constraint associated with the domestication and breeding processes. Purifying selection was, nevertheless, stronger in significantly differentiated pathways than in random pathways, mainly in Europe. We conclude that pathway analysis facilitates the biological interpretation of genome-wide studies. Notably, in the case of pig, behavior played an important role, among other physiological and developmental processes

Whole-genome sequencing reveals insights into the adaptation of French Charolais cattle to Cuban tropical conditions

In the early 20th century, Cuban farmers imported Charolais cattle (CHFR) directly from France. These animals are now known as Chacuba (CHCU) and have become adapted to the rough environmental tropical conditions in Cuba. These conditions include long periods of drought and food shortage with extreme temperatures that European taurine cattle have difficulty coping with. In this study, we used whole-genome sequence data from 12 CHCU individuals together with 60 whole-genome sequences from six additional taurine, indicus and crossed breeds to estimate the genetic diversity, structure and accurate ancestral origin of the CHCU animals. Although CHCU animals are assumed to form a closed population, the results of our admixture analysis indicate a limited introgression of Bos indicus. We used the extended haplotype homozygosity (EHH) approach to identify regions in the genome that may have had an important role in the adaptation of CHCU to tropical conditions. Putative selection events occurred in genomic regions with a high proportion of Bos indicus, but they were not sufficient to explain adaptation of CHCU to tropical conditions by Bos indicus introgression only. EHH suggested signals of potential adaptation in genomic windows that include genes of taurine origin involved in thermogenesis (ATP9A, GABBR1, PGR, PTPN1 and UCP1) and hair development (CCHCR1 and CDSN). Within these genes, we identified single nucleotide polymorphisms (SNPs) that may have a functional impact and contribute to some of the observed phenotypic differences between CHCU and CHFR animals. Whole-genome data confirm that CHCU cattle are closely related to Charolais from France (CHFR) and Canada, but also reveal a limited introgression of Bos indicus genes in CHCU. We observed possible signals of recent adaptation to tropical conditions between CHCU and CHFR founder populations, which were largely independent of the Bos indicus introgression. Finally, we report candidate genes and variants that may have a functional impact and explain some of the phenotypic differences observed between CHCU and CHFR cattle

Clinical and molecular study of patients with thyroid dyshormogenesis and variants in the thyroglobulin gene

Hipotiroïdisme congènit; Tiroglobulina; Dishormonogènesi tiroïdalHipotiroidismo congénito; Tiroglobulina; Dishormonogénesis tiroideaCongenital hypothyroidism; Thyroglobulin; Thyroid dyshormonogenesisIntroduction: Defects in any thyroid hormone synthesis steps cause thyroid dyshormonogenesis (THD). THD due to thyroglobulin (TG) gene variants is a cause of congenital hypothyroidism (CH) with a wide clinical spectrum, ranging from mild to severe permanent hypothyroidism. We present high-throughput sequencing results of patients with TG variants. Methods: A CH high-throughput sequencing-panel of the main genes involved in the regulation of thyroid hormonogenesis was performed to identify those TG variants that may be related to patient THD phenotype. Results: We identified 21 TG gene variants in 19 patients (11.8%) which could explain their phenotype. Ten of those (47.6%) were not previously described. CH was biochemically severe in these 19 patients. Eight of them were reevaluated after one month of discontinuing LT4 treatment and all had severe permanent hypothyroidism. We also identified another 16 patients who presented heterozygous TG variants, of whom, at reevaluation, five had mild permanent and only one had severe permanent hypothyroidisms. Discussions: In this study, 10 novel and 11 previously reported variants in the TG gene have been identified that could explain the phenotype of 19 patients from non-consanguineous families from a large THD cohort. Although not all these TG gene variants can explain all the patients’ THD phenotypes, some of them had severe or mild permanent hypothyroidism at reevaluation.The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Instituto de Salud Carlos III (www.isciii.es/; Madrid, Spain) and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER, http://www.ciberer.es; U-712)