Smitchger Jamin A, Taylor J Bret, Mousel Michelle R, Schaub Daniel, Thorne Jacob W, Becker Gabrielle M, Murdoch Brenda M
Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID, United States.
USDA, Agriculture Research Service, Range Sheep Production Efficiency Research Unit, U.S. Sheep Experiment Station, Dubois, ID, United States.
Front Genet. 2024 May 27;15:1398123. doi: 10.3389/fgene.2024.1398123. eCollection 2024.
Improving ewe longevity is an important breeding and management goal, as death loss and early culling of mature ewes are economic burdens in the sheep industry. Ewe longevity can be improved by selecting for positive reproductive outcomes. However, the breeding approaches for accomplishing this come with the challenge of recording a lifetime trait. Characterizing genetic factors underpinning ewe longevity and related traits could result in the development of genomic selection strategies to improve the stayability of sheep through early, informed selection of replacement ewes. Towards this aim, a genome-wide association study (GWAS) was performed to identify genetic markers associated with ewe longevity, reproductive, and production traits. Traits evaluated included longevity (i.e., length of time in the flock), parity and the lifetime number of lambs born, lambs born alive, lambs weaned, and weight of lambs weaned. Ewe records from previous studies were used. Specifically, Rambouillet (n = 480), Polypay (n = 404), Suffolk (n = 182), and Columbia (n = 64) breed ewes (N = 1,130) were analyzed against 503,617 SNPs in across-breed and within-breed GWAS conducted with the Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK) model in R. The across-breed GWAS identified 25 significant SNPs and the within-breed GWAS for Rambouillet, Polypay, and Suffolk ewes identified an additional 19 significant SNPs. The most significant markers were rs411309094 (13:22,467,143) associated with longevity in across-breed GWAS (-value = 8.3E-13) and rs429525276 (2:148,398,336) associated with both longevity (-value = 6.4E-15) and parity (-value = 4.8E-15) in Rambouillet GWAS. Significant SNPs were identified within or in proximity (±50 kb) of genes with known or proposed roles in reproduction, dentition, and the immune system. These genes include and . This study proposes multiple SNPs as candidates for use in selection indices and suggests genes for further research towards improving understanding of the genetic factors contributing to longevity, reproductive, and production traits of ewes.
提高母羊寿命是一项重要的育种和管理目标，因为成年母羊的死亡损失和过早淘汰是养羊业的经济负担。通过选择积极的繁殖结果可以提高母羊寿命。然而，实现这一目标的育种方法面临着记录终身性状的挑战。确定影响母羊寿命及相关性状的遗传因素，可能会促使基因组选择策略的发展，以便通过早期、明智地选择后备母羊来提高绵羊的留种率。为实现这一目标，开展了一项全基因组关联研究（GWAS），以确定与母羊寿命、繁殖和生产性状相关的遗传标记。评估的性状包括寿命（即羊群中的时间长度）、胎次以及终身产羔数、产活羔数、断奶羔羊数和断奶羔羊体重。使用了先前研究中的母羊记录。具体而言，对兰布耶（n = 480）、波吕佩（n = 404）、萨福克（n = 182）和哥伦比亚（n = 64）品种的母羊（N = 1,130）进行分析，在R软件中采用贝叶斯信息和连锁不平衡迭代嵌套关键路径（BLINK）模型进行跨品种和品种内的GWAS分析，涉及503,617个单核苷酸多态性（SNP）。跨品种GWAS鉴定出25个显著的SNP，兰布耶、波吕佩和萨福克母羊的品种内GWAS又鉴定出19个显著的SNP。最显著的标记是跨品种GWAS中与寿命相关的rs411309094（13:22,467,143）（P值 = 8.3E - 13），以及兰布耶GWAS中与寿命（P值 = 6.4E - 15）和平胎次（P值 = 4.8E - 15）均相关的rs429525276（2:148,398,336）。在已知或推测在繁殖、牙齿发育和免疫系统中起作用的基因内部或附近（±50 kb）鉴定出了显著的SNP。这些基因包括…… 本研究提出多个SNP作为选择指数的候选标记，并建议对相关基因进行进一步研究，以加深对影响母羊寿命、繁殖和生产性状的遗传因素的理解。
