Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya
Understanding the genetic structure of adaptation and productivity in challenging environments is necessary for designing breeding programs that suit such conditions. Crossbred dairy cattle in East Africa resulting from over 60 years of crossing exotic dairy breeds with indigenous cattle plus inter-...
| Autores principales: | , , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
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Frontiers Media
2020
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| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/109411 |
| _version_ | 1855532015790587904 |
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| author | Aliloo, H. Mrode, Raphael A. Okeyo Mwai, Ally Gibson, John P. |
| author_browse | Aliloo, H. Gibson, John P. Mrode, Raphael A. Okeyo Mwai, Ally |
| author_facet | Aliloo, H. Mrode, Raphael A. Okeyo Mwai, Ally Gibson, John P. |
| author_sort | Aliloo, H. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Understanding the genetic structure of adaptation and productivity in challenging environments is necessary for designing breeding programs that suit such conditions. Crossbred dairy cattle in East Africa resulting from over 60 years of crossing exotic dairy breeds with indigenous cattle plus inter-se matings, form a highly variable admixed population. This population has been subject to natural selection in response to environmental stresses such as harsh climate, low quality feeds, poor management and strong disease challenge. Here, we combine two complementary sets of analyses, genome-wide association (GWA) and signatures of selection (SoS), to identify genomic regions that contribute to variation in milk yield and/or contribute to adaptation in admixed dairy cattle of Kenya. Our GWA separates SNP effects due to ancestral origin of alleles from effects due to within-population linkage disequilibrium. The results indicate that many genomic regions contributed to the high milk production potential of modern dairy breeds, with no region having an exceptional effect. For SoS, we used two haplotype-based tests to compare haplotype length variation within admixed and between admixed and East African Shorthorn Zebu cattle populations. The integrated haplotype score (iHS) analysis identified 16 candidate regions for positive selection in the admixed cattle while the between population Rsb test detected 24 divergently selected regions in the admixed cattle compared to East African Shorthorn Zebu. We compare the results from GWA and SoS to validate the most significant SoS results and show that 4 candidate regions for selection intersect with GWA results. These regions harboured genes in several enriched annotation clusters and overlapped with previously found QTLs and associations for different traits in cattle. If validated, the GWA and SoS results indicate strong potential for SNP-based genomic selection for genetic improvement of smallholder crossbred cattle |
| format | Journal Article |
| id | CGSpace109411 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | Frontiers Media |
| publisherStr | Frontiers Media |
| record_format | dspace |
| spelling | CGSpace1094112024-10-03T07:40:58Z Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya Aliloo, H. Mrode, Raphael A. Okeyo Mwai, Ally Gibson, John P. animal breeding genetics dairies dairying cattle livestock Understanding the genetic structure of adaptation and productivity in challenging environments is necessary for designing breeding programs that suit such conditions. Crossbred dairy cattle in East Africa resulting from over 60 years of crossing exotic dairy breeds with indigenous cattle plus inter-se matings, form a highly variable admixed population. This population has been subject to natural selection in response to environmental stresses such as harsh climate, low quality feeds, poor management and strong disease challenge. Here, we combine two complementary sets of analyses, genome-wide association (GWA) and signatures of selection (SoS), to identify genomic regions that contribute to variation in milk yield and/or contribute to adaptation in admixed dairy cattle of Kenya. Our GWA separates SNP effects due to ancestral origin of alleles from effects due to within-population linkage disequilibrium. The results indicate that many genomic regions contributed to the high milk production potential of modern dairy breeds, with no region having an exceptional effect. For SoS, we used two haplotype-based tests to compare haplotype length variation within admixed and between admixed and East African Shorthorn Zebu cattle populations. The integrated haplotype score (iHS) analysis identified 16 candidate regions for positive selection in the admixed cattle while the between population Rsb test detected 24 divergently selected regions in the admixed cattle compared to East African Shorthorn Zebu. We compare the results from GWA and SoS to validate the most significant SoS results and show that 4 candidate regions for selection intersect with GWA results. These regions harboured genes in several enriched annotation clusters and overlapped with previously found QTLs and associations for different traits in cattle. If validated, the GWA and SoS results indicate strong potential for SNP-based genomic selection for genetic improvement of smallholder crossbred cattle 2020-06-09 2020-09-14T08:24:08Z 2020-09-14T08:24:08Z Journal Article https://hdl.handle.net/10568/109411 en Open Access Frontiers Media Aliloo, H., Mrode, R., Okeyo, A.M. and Gibson, J.P. 2020. Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya. Frontiers in Genetics 11:544. |
| spellingShingle | animal breeding genetics dairies dairying cattle livestock Aliloo, H. Mrode, Raphael A. Okeyo Mwai, Ally Gibson, John P. Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya |
| title | Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya |
| title_full | Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya |
| title_fullStr | Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya |
| title_full_unstemmed | Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya |
| title_short | Ancestral haplotype mapping for GWAS and detection of signatures of selection in admixed dairy cattle of Kenya |
| title_sort | ancestral haplotype mapping for gwas and detection of signatures of selection in admixed dairy cattle of kenya |
| topic | animal breeding genetics dairies dairying cattle livestock |
| url | https://hdl.handle.net/10568/109411 |
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