British Sheep Breeds as a Part of World Sheep Gene Pool Landscape: Looking into Genomic Applications.
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ABSTRACT:
SUBMITTER: Romanov MN
PROVIDER: S-EPMC8103502 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Sheep farming is a major source of meat in Morocco and plays a key role in the country's agriculture. This study aims at characterizing the whole-genome diversity and demographic history of the main Moroccan sheep breeds, as well as to identify selection signatures within and between breeds. Whole genome data from 87 individuals representing the five predominant local breeds were used to estimate their level of neutral genetic diversity and to infer the variation of their effective population size over time. In addition, we used two methods to detect selection signatures: either for detecting selective sweeps within each breed separately or by detecting differentially selected regions by contrasting different breeds. We identified hundreds of genomic regions putatively under selection, which related to several biological terms involved in local adaptation or the expression of zootechnical performances such as Growth, UV protection, Cell maturation or Feeding behavior. The results of this study revealed selection signatures in genes that have an important role in traits of interest and increased our understanding of how genetic diversity is distributed in these local breeds. Thus, Moroccan local sheep breeds exhibit both a high genetic diversity and a large set of adaptive variations, and therefore, represent a valuable genetic resource for the conservation of sheep in the context of climate change.
| S-EPMC8675355 | biostudies-literature
Project description:BackgroundFat tail is a unique trait in sheep acquired during domestication. Several genomic analyses have been conducted in sheep breeds from limited geographic origins to identify the genetic factors underlying this trait. Nevertheless, these studies obtained different candidates. The results of these regional studies were easily biased by the breed structures.ResultsTo minimize the bias and distinguish the true candidates, we used an extended data set of 968 sheep representing 18 fat-tailed breeds and 14 thin-tailed breeds from around the world, and integrated two statistical tests to detect selection signatures, including Genetic Fixation Index (FST) and difference of derived allele frequency (ΔDAF). The results showed that platelet derived growth factor D (PDGFD) exhibited the highest genetic differentiation between fat- and thin-tailed sheep breeds. Analysis of sequence variation identified that a 6.8-kb region within the first intron of PDGFD is likely the target of positive selection and contains regulatory mutation(s) in fat-tailed sheep. Histological and gene expression analyses demonstrated that PDGFD expression is associated with maturation and hemostasis of adipocytes. Further retrospective analysis of public transcriptomic datasets revealed that PDGFD expression is down-regulated during adipogenesis in both human and mouse, and is higher in fat tissues of obese individuals than that in lean individuals.ConclusionsThese results reveal that PDGFD is the predominant factor for the fat tail phenotype in sheep by contributing to adiopogenesis and maintaining the hemostasis of mature adipocytes. This study provides insights into the selection of fat-tailed sheep and has important application to animal breeding, as well as obesity-related human diseases.
| S-EPMC7670677 | biostudies-literature
Project description: Not available
| S-EPMC11240672 | biostudies-literature
Project description:BackgroundThe importance of sheep breeding in the Mediterranean part of the eastern Adriatic has a long tradition since its arrival during the Neolithic migrations. Sheep production system is extensive and generally carried out in traditional systems without intensive systematic breeding programmes for high uniform trait production (carcass, wool and milk yield). Therefore, eight indigenous Croatian sheep breeds from eastern Adriatic treated here as metapopulation (EAS), are generally considered as multipurpose breeds (milk, meat and wool), not specialised for a particular type of production, but known for their robustness and resistance to certain environmental conditions. Our objective was to identify genomic regions and genes that exhibit patterns of positive selection signatures, decipher their biological and productive functionality, and provide a "genomic" characterization of EAS adaptation and determine its production type.ResultsWe identified positive selection signatures in EAS using several methods based on reduced local variation, linkage disequilibrium and site frequency spectrum (eROHi, iHS, nSL and CLR). Our analyses identified numerous genomic regions and genes (e.g., desmosomal cadherin and desmoglein gene families) associated with environmental adaptation and economically important traits. Most candidate genes were related to meat/production and health/immune response traits, while some of the candidate genes discovered were important for domestication and evolutionary processes (e.g., HOXa gene family and FSIP2). These results were also confirmed by GO and QTL enrichment analysis.ConclusionsOur results contribute to a better understanding of the unique adaptive genetic architecture of EAS and define its productive type, ultimately providing a new opportunity for future breeding programmes. At the same time, the numerous genes identified will improve our understanding of ruminant (sheep) robustness and resistance in the harsh and specific Mediterranean environment.
| S-EPMC10626677 | biostudies-literature
Project description:Understanding the relationships among geography, climate, and genetics is increasingly important for animal farming and breeding. In this study, we examine these inter-relationships in the context of local cattle and sheep breeds distributed along the Italian territory. To this aim, we used redundancy analysis on genomic data from previous projects combined with geographical coordinates and corresponding climatic data. The effect of geographic factors (latitude and longitude) was more important in sheep (26.4%) than that in cattle (13.8%). Once geography had been partialled out of analysis, 10.1% of cattle genomic diversity and 13.3% of that of sheep could be ascribed to climatic effects. Stronger geographic effects in sheep can be related to a combination of higher pre-domestication genetic variability together with biological and productive specificities. Climate alone seems to have had less impact on current genetic diversity in both species, even if climate and geography are greatly confounded. Results confirm that both species are the result of complex evolutionary histories triggered by interactions between human needs and environmental conditions.
| S-EPMC9454691 | biostudies-literature
Project description:BackgroundA run of homozygosity (ROH) is a consecutive tract of homozygous genotypes in an individual that indicates it has inherited the same ancestral haplotype from both parents. Genomic inbreeding can be quantified based on ROH. Genomic regions enriched with ROH may be indicative of selection sweeps and are known as ROH islands. We carried out ROH analyses in five Chinese indigenous sheep breeds; Altay sheep (n = 50 individuals), Large-tailed Han sheep (n = 50), Hulun Buir sheep (n = 150), Short-tailed grassland sheep (n = 150), and Tibetan sheep (n = 50), using genotypes from an Ovine Infinium HD SNP BeadChip.ResultsA total of 18,288 ROH were identified. The average number of ROH per individual across the five sheep breeds ranged from 39 (Hulun Buir sheep) to 78 (Large-tailed Han sheep) and the average length of ROH ranged from 0.929 Mb (Hulun Buir sheep) to 2.544 Mb (Large-tailed Han sheep). The effective population size (Ne) of Altay sheep, Large-tailed Han sheep, Hulun Buir sheep, Short-tailed grassland sheep and Tibetan sheep were estimated to be 81, 78, 253, 238 and 70 five generations ago. The highest ROH-based inbreeding estimate (FROH) was 0.0808 in Large-tailed Han sheep, whereas the lowest FROH was 0.0148 in Hulun Buir sheep. Furthermore, the highest proportion of long ROH fragments (> 5 Mb) was observed in the Large-tailed Han sheep breed which indicated recent inbreeding. In total, 49 ROH islands (the top 0.1% of the SNPs most commonly observed in ROH) were identified in the five sheep breeds. Three ROH islands were common to all the five sheep breeds, and were located on OAR2: 12.2-12.3 Mb, OAR12: 78.4-79.1 Mb and OAR13: 53.0-53.6 Mb. Three breed-specific ROH islands were observed in Altay sheep (OAR15: 3.4-3.8 Mb), Large-tailed Han sheep (ORA17: 53.5-53.8 Mb) and Tibetan sheep (ORA5:19.8-20.2 Mb). Collectively, the ROH islands harbored 78 unique genes, including 19 genes that have been documented as having associations with tail types, adaptation, growth, body size, reproduction or immune response.ConclusionDifferent ROH patterns were observed in five Chinese indigenous sheep breeds, which reflected their different population histories. Large-tailed Han sheep had the highest genomic inbreeding coefficients and the highest proportion of long ROH fragments indicating recent inbreeding. Candidate genes in ROH islands could be used to illustrate the genetic characteristics of these five sheep breeds. Our findings contribute to the understanding of genetic diversity and population demography, and help design and implement breeding and conservation strategies for Chinese sheep.
| S-EPMC8340518 | biostudies-literature
Project description:Through long term natural and artificial selection, domestic sheep (Ovis aries) have become adapted to a diverse range of agro-ecological environments and display multiple phenotypic traits. Characterization of diversity and selection signature is essential for genetic improvement, understanding of environmental adaptation, as well as utilization and conservation of sheep genetic resources. Here, we aimed to assess genomic diversity, population structure, and genomic selection among five Chinese native sheep breeds using 600K high density SNP genotypes. A total of 96 animals of the five breeds were selected from different geographical locations with extremely dry or humid conditions. We found a high proportion of informative SNPs, ranging from 93.3% in Yabuyi to 95.5% in Wadi, Hu, and Hetian sheep. The average pairwise population differentiation (FST) between the breeds was 0.048%, ranging from 0.022% to 0.054%, indicating their low to moderate differentiation. PCA, ADMIXTURE, and phylogenetic tree analyses revealed a clustering pattern of the five Chinese sheep breeds according to their geographical distribution, tail type, coat color, body size, and breeding history. The genomic regions under putative selection identified by FST and XP-EHH approaches frequently overlapped across the breeds, and spanned genes associated with adaptation to extremely dry or humid environments, innate and adaptive immune responses, and growth, wool, milk, and reproduction traits. The present study offers novel insight into genomic adaptation to dry and humid climates in sheep among other domestic animals and provides a valuable resource for further investigation. Moreover, it contributes useful information to sustainable utilization and conservation of sheep genetic resources.
| S-EPMC7290715 | biostudies-literature
Project description:It is commonly believed that race is perceived through another's facial features, such as skin color. In the present research, we demonstrate that cues to social status that often surround a face systematically change the perception of its race. Participants categorized the race of faces that varied along White-Black morph continua and that were presented with high-status or low-status attire. Low-status attire increased the likelihood of categorization as Black, whereas high-status attire increased the likelihood of categorization as White; and this influence grew stronger as race became more ambiguous (Experiment 1). When faces with high-status attire were categorized as Black or faces with low-status attire were categorized as White, participants' hand movements nevertheless revealed a simultaneous attraction to select the other race-category response (stereotypically tied to the status cue) before arriving at a final categorization. Further, this attraction effect grew as race became more ambiguous (Experiment 2). Computational simulations then demonstrated that these effects may be accounted for by a neurally plausible person categorization system, in which contextual cues come to trigger stereotypes that in turn influence race perception. Together, the findings show how stereotypes interact with physical cues to shape person categorization, and suggest that social and contextual factors guide the perception of race.
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Project description:Technological advances have led to an explosive growth of high-throughput functional genomic data. Exploiting the correlation among different data types, it is possible to predict one functional genomic data type from other data types. Prediction tools are valuable in understanding the relationship among different functional genomic signals. They also provide a cost-efficient solution to inferring the unknown functional genomic profiles when experimental data are unavailable due to resource or technological constraints. The predicted data may be used for generating hypotheses, prioritizing targets, interpreting disease variants, facilitating data integration, quality control, and many other purposes. This article reviews various applications of prediction methods in functional genomics, discusses analytical challenges, and highlights some common and effective strategies used to develop prediction methods for functional genomic data.
| S-EPMC5599299 | biostudies-literature
Project description:In recent times, community-based breeding programs (CBBPs) have been advocated as the best strategy for genetic improvement of local breeds in smallholder farms in developing countries. Since 2009, CBBPs have been implemented for Ethiopian Bonga and Menz sheep to improve growth rates resulting in significant genetic gains in 6-month weights. With the hypothesis that selection could be impacting their genomes, we systematically screened for possible genome changes in the two breeds by analyzing 600K BeadChip genotype data of 151 individuals (with the highest breeding values for 6-month weights) from CBBP flocks against 98 individuals from non-CBBP flocks. We observed no differences in genetic diversity and demographic dynamics between CBBP and non-CBBP flocks. Selection signature analysis employing ROH, logistic regression genome-wide association study , FST , XP-EHH and iHS revealed 5 (Bonga) and 11 (Menz) overlapping regions under selection, that co-localized with QTLs for production (body size/weight, growth, milk yield), meat/milk quality, and health/parasite resistance, suggesting that the decade-long selection has likely started to impact their genomes. However, genome-wide genetic differentiation between the CBBP and non-CBBP flocks is not yet clearly evident.
| S-EPMC10138745 | biostudies-literature