Association of lipid-related genes implicated in conceptus elongation with female fertility traits in dairy cattle

摘要

Elongation of the preimplantation conceptus is arequirement for pregnancy success in ruminants, andfailures in this process are highly associated with subfertilityin dairy cattle. Identifying genetic markersthat are related to early conceptus development andsurvival and utilizing these markers in selective breedingcan improve the reproductive efficiency of dairyherds. Here, we evaluated the association of 1,679 SNPmarkers within or close to 183 candidate genes involvedin lipid metabolism of the elongating conceptus withdifferent fertility traits in US Holstein cattle. A totalof 27,371 bulls with predicted transmitting ability recordsfor daughter pregnancy rate, cow conception rate,and heifer conception rate were used as the discoverypopulation. The associations found in the discoverypopulation were validated using 2 female populations(1,122 heifers and 2,138 lactating cows) each with 4fertility traits, including success to first insemination,number of services per conception, age at first conceptionfor heifers, or days open for cows. Marker effectswere estimated using a linear mixed model with SNPgenotype as a linear covariate and a random polygeniceffect. After multiple testing correction, 39 SNP flagging27 candidate genes were associated with at leastone fertility trait in the discovery population. Of these39 markers, 3 SNP were validated in the heifer populationand 4 SNP were validated in the cow population.The 3 SNP validated in heifers are located within ornear genes CAT, MYOF, and RBP4, and the 4 SNPvalidated in lactating cows are located within or closeto genes CHKA, GNAI1, and HMOX2. These validatedgenes seem to be relevant for reducing pregnancylosses, and the SNP within these genes are excellentcandidates for inclusion in genomic tests to improvereproductive performance in dairy cattle.