Assessment of genetic diversity and Signatures of Selection in Korean Cattle Populations

2019 ◽  
Vol 3 (4) ◽  
2021 ◽  
Author(s):  
Adéla Nosková ◽  
Meenu Bhati ◽  
Naveen Kumar Kadri ◽  
Danang Crysnanto ◽  
Stefan Neuenschwander ◽  
...  

Abstract Background The key-ancestor approach has been frequently applied to prioritize individuals for whole-genome sequencing based on their marginal genetic contribution to current populations. Using this approach, we selected 70 key ancestors from two lines of the Swiss Large White breed that have been selected divergently for fertility and fattening traits and sequenced their genomes with short paired-end reads. Results Using pedigree records, we estimated the effective population size of the dam and sire line to 72 and 44, respectively. In order to assess sequence variation in both lines, we sequenced the genomes of 70 boars at an average coverage of 16.69-fold. The boars explained 87.95 and 95.35% of the genetic diversity of the breeding populations of the dam and sire line, respectively. Reference-guided variant discovery using the GATK revealed 26,862,369 polymorphic sites. Principal component, admixture and FST analyses indicated considerable genetic differentiation between the lines. Genomic inbreeding quantified using runs of homozygosity was higher in the sire than dam line (0.28 vs 0.26). Using two complementary approaches (CLR and iHS), we detected 51 signatures of selection. However, only six signatures of selection overlapped between both lines. We used the sequenced haplotypes of the 70 key ancestors as a reference panel to call 22,618,811 genotypes in 175 pigs that had been sequenced at very low coverage (1.11-fold) using GLIMPSE. The genotype concordance, non-reference sensitivity and non-reference discrepancy between thus inferred and Illumina PorcineSNP60 BeadChip-called genotypes was 97.60, 98.73 and 3.24%, respectively. The low-pass sequencing-derived genomic relationship coefficients were highly correlated (r > 0.99) with those obtained from microarray genotyping. Conclusions We assessed genetic diversity within and between two lines of the Swiss Large White pig breed. Our analyses revealed considerable differentiation, even though the split into two populations occurred only few generations ago. The sequenced haplotypes of the key ancestor animals enabled us to implement genotyping by low-pass sequencing which offers an intriguing cost-effective approach to increase the variant density over current array-based genotyping by more than 350-fold.


2015 ◽  
Vol 49 (2) ◽  
pp. 37-46 ◽  
Author(s):  
Tae-Jeong Choi ◽  
◽  
Seung-Soo Lee ◽  
Kwang-Hyeon Cho ◽  
Duhak Yoon ◽  
...  

2013 ◽  
Vol 12 (1) ◽  
pp. 114 ◽  
Author(s):  
Cristina Mendes ◽  
Patrícia Salgueiro ◽  
Vicenta Gonzalez ◽  
Pedro Berzosa ◽  
Agustin Benito ◽  
...  

2016 ◽  
Author(s):  
Simon Henry Martin ◽  
Markus Moest ◽  
Wiliam J Palmer ◽  
Camilo Salazar ◽  
W. Owen McMillan ◽  
...  

A combination of selective and neutral evolutionary forces shape patterns of genetic diversity in nature. Among the insects, most previous analyses of the roles of drift and selection in shaping variation across the genome have focused on the genus Drosophila. A more complete understanding of these forces will come from analysing other taxa that differ in population demography and other aspects of biology. We have analysed diversity and signatures of selection in the neotropical Heliconius butterflies using resequenced genomes from 58 wild-caught individuals of H. melpomene, and another 21 resequenced genomes representing 11 related species. By comparing intra-specific diversity and inter-specific divergence, we estimate that 31% of amino acid substitutions between Heliconius species are adaptive. Diversity at putatively neutral sites is negatively correlated with gene density and positively correlated with recombination rate, indicating widespread linked selection. This process also manifests in significantly reduced diversity on longer chromosomes, consistent with lower recombination rates. Genetic hitchhiking around beneficial non-synonymous mutations has also had a significant impact on genetic variation in this species, but evidence for strong selective sweeps was limited overall. We did however identify two regions where distinct haplotypes have swept in different populations, leading to increased population differentiation. On the whole, our study suggests that positive selection is less pervasive in these butterflies as compared to fruit flies; a fact that curiously results in very similar levels of neutral diversity in these very different insects.


2021 ◽  
Author(s):  
Josue Chinchilla-Vargas ◽  
Jonathan R. Meerbeek ◽  
Max F. Rothschild ◽  
Francesca Bertolini

Abstract Background Muskellunge (Esox masquinongy) is the largest and most prized game fish for anglers in North America. However, little is known about Muskellunge genetic diversity in Iowa’s propagation program. We used whole genome sequence from 12 brooding individuals from Iowa and publicly available RAD-seq of 625 individuals from Saint-Lawrence river in Canada to study the genetic differences between populations, analyze signatures of selection that might shed light on environmental adaptations, and evaluate the levels of genetic diversity in both populations. Given that there is no reference genome available for Muskellunge, reads were aligned to the genome of Pike (Esox lucius), a closely-related species.Results Variant calling produced 7,886,471 biallelic variants for the Iowa population and 16,867 high-quality SNPs that overlap with the Canadian samples. The Ti/Tv values were 1.09 and 1.29 for samples from Iowa and Canada, respectively. PCA and Admixture analyses showed a large genetic difference between Canadian and Iowan populations. Moreover, PCA showed clustering by sex in the Iowan population although widow-based Fst did not find outlier regions. Window-based pooled heterozygosity found 6 highly heterozygous windows containing 244 genes in the Iowa population and Fst comparing the Iowa and Canadian populations found 14 windows with Fst values larger than 0.9 containing 641 genes. One enriched GO term (sensory perception of pain) was found through pooled heterozygosity analyzes. Although not significant, several enriched GO terms associated to growth and development were found through Fst analyses.Inbreeding calculated as Froh was 0.03 on average for the Iowa population and 0.32 on average for the Canadian samples. The Canadian inbreeding rate appears to be higher, presumably due to isolation of subpopulations, than the inbreeding rate of the Iowa population.Conclusions This study was the first to document that brood stock Muskellunge from Iowa showed marked genetic differences with the Canadian population. Additionally, despite genetic differentiation based on sex has been observed, no major locus has been detected. Inbreeding does not seem to be an immediate concern for Muskellunge in Iowa, but apparent isolation of subpopulations has caused levels of homozygosity to increase in the Canadian Muskellunge population. Finally, these results prove the validity of using genomes of closely related species to perform genomic analyses when no reference genome assembly is available.


2021 ◽  
Author(s):  
Josue Chinchilla-Vargas ◽  
Max F. Rothschild ◽  
Francesca Bertolini

Abstract Background Muskellunge (Esox masquinongy) is the largest and most prized game fish for anglers in North America. However, little is known about Muskellunge genetic diversity in Iowa’s propagation program. We used whole genome sequence from 12 brooding individuals from Iowa and publicly available RAD-seq of 625 individuals from Saint-Lawrence river in Canada to study the genetic differences between populations, analyze signatures of selection that might shed light on environmental adaptations, and evaluate the levels of genetic diversity in both populations. Given that there is no reference genome available for Muskellunge, reads were aligned to the genome of Pike (Esox lucius), a closely-related species. Results Variant calling produced 7,886,471 biallelic variants for the Iowa population and 16,867 high quality SNPs that overlap with the Canadian samples. The Ti/Tv values were 1.09 and 1.29 for samples from Iowa and Canada, respectively. PCA and Admixture analyses showed a large genetic difference between Canadian and Iowan populations. Moreover, PCA showed a clustering by sex in the Iowan population although widow-based Fst did not find outlier regions. Window based pooled heterozygosity found 6 highly heterozygous windows containing 244 genes in the Iowa population and Fst comparing the Iowa and Canadian populations found 14 windows with Fst values larger than 0.9 containing 641 genes. One enriched GO term (sensory perception of pain) was found through pooled heterozygosity analyzes. Although not significant, several enriched GO terms associated to growth and development were found through Fst analyses. Inbreeding calculated as Froh was 0.03 on average for the Iowa population and 0.32 on average for the Canadian samples. The inbreeding rate appears is presumably due to isolation of subpopulations. Conclusions This study is the first of its kind in Muskellunge from Iowa in which captured brood stock showed marked genetic differences with the Canadian population. Additionally, despite genetic differentiation based on sex has been observed, no major locus has been detected . Inbreeding does not seem to be an immediate concern for Muskellunge in Iowa, isolation of subpopulations has caused levels of homozygosity to increase in the Canadian Muskellunge population. These results prove the validity of using genomes of closely related species to perform genomic analyses when no reference genome assembly is available.


2016 ◽  
Vol 47 (6) ◽  
pp. 647-657 ◽  
Author(s):  
T. Iso-Touru ◽  
M. Tapio ◽  
J. Vilkki ◽  
T. Kiseleva ◽  
I. Ammosov ◽  
...  

2018 ◽  
Vol 216 ◽  
pp. 100-108 ◽  
Author(s):  
L. Xu ◽  
W.G. Zhang ◽  
H.X. Shen ◽  
Y. Zhang ◽  
Y.M. Zhao ◽  
...  

2021 ◽  
Author(s):  
Josue Chinchilla-Vargas ◽  
Jonathan Meerbeek ◽  
Max F. Rothschild ◽  
Francesca Bertolini

Abstract Background Muskellunge (Esox masquinongy) is the largest and most prized game fish for anglers in North America. However, little is known about Muskellunge genetic diversity in Iowa’s propagation program. We used whole genome sequence from 12 brooding individuals from Iowa and publicly available RAD-seq of 625 individuals from Saint-Lawrence river in Canada to study the genetic differences between populations, analyze signatures of selection that might shed light on environmental adaptations, and evaluate the levels of genetic diversity in both populations. Given that there is no reference genome available for Muskellunge, reads were aligned to the genome of Pike (Esox lucius), a closely-related species.ResultsVariant calling produced 7,886,471 biallelic variants for the Iowa population and 16,867 high quality SNPs that overlap with the Canadian samples. The Ti/Tv values were 1.09 and 1.29 for samples from Iowa and Canada, respectively. PCA and Admixture analyses showed a large genetic difference between Canadian and Iowan populations. Moreover, PCA showed a clustering by sex in the Iowan population although widow-based Fst did not find outlier regions. Window based pooled heterozygosity found 6 highly heterozygous windows containing 244 genes in the Iowa population and Fst comparing the Iowa and Canadian populations found 14 windows with Fst values larger than 0.9 containing 641 genes. One enriched GO term (sensory perception of pain) was found through pooled heterozygosity analyzes. Although not significant, several enriched GO terms associated to growth and development were found through Fst analyses.Inbreeding calculated as Froh was 0.03 on average for the Iowa population and 0.32 on average for the Canadian samples. The Canadian inbreeding rate appears is presumably due to isolation of subpopulations.ConclusionsThis study is the first of its kind in Muskellunge from Iowa in which captured brood stock showed marked genetic differences with the Canadian population. Additionally, despite genetic differentiation based on sex has been observed, no major locus has been detected. Inbreeding does not seem to be an immediate concern for Muskellunge in Iowa, but apparent isolation of subpopulations has caused levels of homozygosity to increase in the Canadian Muskellunge population.These results prove the validity of using genomes of closely related species to perform genomic analyses when no reference genome assembly is available.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pedro H. F. Freitas ◽  
Yachun Wang ◽  
Ping Yan ◽  
Hinayah R. Oliveira ◽  
Flavio S. Schenkel ◽  
...  

Understanding the biological mechanisms of climatic adaptation is of paramount importance for the optimization of breeding programs and conservation of genetic resources. The aim of this study was to investigate genetic diversity and unravel genomic regions potentially under selection for heat and/or cold tolerance in thirty-two worldwide cattle breeds, with a focus on Chinese local cattle breeds adapted to divergent climatic conditions, Datong yak (Bos grunniens; YAK), and Bali (Bos javanicus) based on dense SNP data. In general, moderate genetic diversity levels were observed in most cattle populations. The proportion of polymorphic SNP ranged from 0.197 (YAK) to 0.992 (Mongolian cattle). Observed and expected heterozygosity ranged from 0.023 (YAK) to 0.366 (Sanhe cattle; SH), and from 0.021 (YAK) to 0.358 (SH), respectively. The overall average inbreeding (±SD) was: 0.118 ± 0.028, 0.228 ± 0.059, 0.194 ± 0.041, and 0.021 ± 0.004 based on the observed versus expected number of homozygous genotypes, excess of homozygosity, correlation between uniting gametes, and runs of homozygosity (ROH), respectively. Signatures of selection based on multiple scenarios and methods (FST, HapFLK, and ROH) revealed important genomic regions and candidate genes. The candidate genes identified are related to various biological processes and pathways such as heat-shock proteins, oxygen transport, anatomical traits, mitochondrial DNA maintenance, metabolic activity, feed intake, carcass conformation, fertility, and reproduction. This highlights the large number of biological processes involved in thermal tolerance and thus, the polygenic nature of climatic resilience. A comprehensive description of genetic diversity measures in Chinese cattle and YAK was carried out and compared to 24 worldwide cattle breeds to avoid potential biases. Numerous genomic regions under positive selection were detected using three signature of selection methods and candidate genes potentially under positive selection were identified. Enriched function analyses pinpointed important biological pathways, molecular function and cellular components, which contribute to a better understanding of the biological mechanisms underlying thermal tolerance in cattle. Based on the large number of genomic regions identified, thermal tolerance has a complex polygenic inheritance nature, which was expected considering the various mechanisms involved in thermal stress response.


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