<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Weaning traits, including preweaning daily gain (PWDG) and weaning weight (WW) are important economic traits, especially for meat type mammals, with high impacts on growth performance and survival rate in higher ages. This study was conducted to perform a genome-wide association study (GWAS) on weaning traits in a meat type breed of sheep. Body weight records of 7557 Lori-Bakhtiari sheep with PWDG and WW records were used to estimate breeding values (EBVs) using an animal mixed model. A total of 132 animals were selected by two-tailed selection strategy, based on EBVs for body weight and then were genotyped using Illumina 50k Ovine SNP chip. After quality control, a total of 130 animals and 41323 SNPs were remained for further analyses. De-regressed estimates of breeding values were used as a pseudo-phenotype in GWAS analysis. Based on Bonferroni-adjusted p-values, five SNPs, located on chromosomes 2, 3, 4, 12 and 22 were significantly (p &lt; 0.05) associated with weaning traits and accounted for 5.06% and 0.37% of total genetic variations of PWDG and WW, respectively. Two SNPs on chromosomes 2 and 3 were located near to previously reported QTLs for weaning traits. Three genes, including <italic>ANGPTL7</italic>, <italic>mTOR</italic> and <italic>WDR11</italic>, were found within 50 kbp distances from the significant SNPs and thus could be considered as candidate genes for weaning traits. The detected QTLs and candidate genes could be studied for construction of breeding programs for genetic improvement of growth performance in meat type sheep.</p></abstract>

Weaning traits, including preweaning daily gain (PWDG) and weaning weight (WW) are important economic traits, especially for meat type mammals, with high impacts on growth performance and survival rate in higher ages. This study was conducted to perform a genome-wide association study (GWAS) on weaning traits in a meat type breed of sheep. Body weight records of 7557 Lori-Bakhtiari sheep with PWDG and WW records were used to estimate breeding values (EBVs) using an animal mixed model. A total of 132 animals were selected by two-tailed selection strategy, based on EBVs for body weight and then were genotyped using Illumina 50k Ovine SNP chip. After quality control, a total of 130 animals and 41323 SNPs were remained for further analyses. De-regressed estimates of breeding values were used as a pseudo-phenotype in GWAS analysis. Based on Bonferroni-adjusted p-values, five SNPs, located on chromosomes 2, 3, 4, 12 and 22 were significantly (p < 0.05) associated with weaning traits and accounted for 5.06% and 0.37% of total genetic variations of PWDG and WW, respectively. Two SNPs on chromosomes 2 and 3 were located near to previously reported QTLs for weaning traits. Three genes, including ANGPTL7, mTOR and WDR11, were found within 50 kbp distances from the significant SNPs and thus could be considered as candidate genes for weaning traits. The detected QTLs and candidate genes could be studied for construction of breeding programs for genetic improvement of growth performance in meat type sheep.

Genome-Wide Association Study of Weaning Traits in Lori-Bakhtiari Sheep

Department of Animal Science, Faculty of Agriculture

Annals of Animal Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Genome-Wide Association Study of Weaning Traits in Lori-Bakhtiari Sheep"}

Weaning traits, including preweaning daily gain (PWDG) and weaning weight (WW) are important economic traits, especially for meat type mammals, with high...

Genome-Wide Association Study of Weaning Traits in Lori-Bakhtiari Sheep

Published Online: Aug 01, 2020

Page range: 811 - 824

Received: Sep 08, 2019

Accepted: Jan 09, 2020

DOI: https://doi.org/10.2478/aoas-2020-0014

Keywords
body weight, growth, quantitative trait loci (QTL), single nucleotide polymorphism (SNP), candidate gene

© 2020 Mohammad Almasi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Genome-Wide Association Study of Weaning Traits in Lori-Bakhtiari Sheep

Published Online: Aug 01, 2020

Page range: 811 - 824

Received: Sep 08, 2019

Accepted: Jan 09, 2020

DOI: https://doi.org/10.2478/aoas-2020-0014

Keywordsbody weight, growth, quantitative trait loci (QTL), single nucleotide polymorphism (SNP), candidate gene

© 2020 Mohammad Almasi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
body weight, growth, quantitative trait loci (QTL), single nucleotide polymorphism (SNP), candidate gene