|KURZ, JACQUELINE - Utah State University|
|ZHOU, YANG - Huazhong Agricultural University|
|WEISS, ROBERT - Utah State University|
|WILSON, DAVID - Utah State University|
|ROOD, KERRY - Utah State University|
|Liu, Ge - George|
|WANG, ZHONGDE - Utah State University|
Submitted to: Immunogenetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/25/2018
Publication Date: 9/30/2018
Citation: Kurz, J.P., Zhou, Y., Weiss, R.B., Wilson, D.J., Rood, K.J., Liu, G., Wang, Z. 2018. A genome-wide association study for mastitis resistance in phenotypically well-characterized Holstein dairy cattle using a selective genotyping approach. Immunogenetics. 71(1):35-47. https://doi.org/10.1007/s00251-018-1088-9.
Interpretive Summary: Bovine mastitis casues large losses in the dairy industry. Using a high-density SNP array, we screened single nucleotide polymorphisms (SNPs) associated with mastitis resistance in Holstein dairy cattle. We identified RASGRP1 as a candidate gene and found teat length as an important trait in mastitis resistance. Farmers, scientist, and policy planners who need improve animal health and production based on genome-enable animal selection will benefit from this study.
Technical Abstract: A decrease in the incidence of bovine mastitis, the costliest disease in the dairy industry, can be facilitated through genetic marker-assisted selective breeding programs. Identification of genomic variants associated with mastitis resistance is an ongoing endeavor for which genome-wide association studies (GWAS) using high-density arrays provide a valuable tool. We identified single nucleotide polymorphisms (SNPs) in Holstein dairy cattle associated with mastitis resistance in a GWAS by using a high-density SNP array. Mastitis-resistant (15) and mastitis-susceptible (28) phenotypic extremes were identified from 224 lactating dairy cows on commercial dairy farm located in Utah based on multiple criteria of mastitis resistance over an 8-month period. Twenty-seven quantitative trait loci (QTLs) for mastitis resistance were identified based on 117 SNPs suggestive of genome-wide significance for mastitis resistance (p = 1 x 10-4), including 10 novel QTLs. Seventeen QTLs overlapped previously-reported QTLs of traits relevant to mastitis, including four QTLs for teat length. One QTL includes the RAS guanyl releasing protein 1 (RASGRP1) gene, a candidate gene for mastitis resistance. This GWAS identifies 117 candidate SNPs and 27 QTLs for mastitis resistance using a selective genotyping approach, including ten novel QTLs. Based on overlap with previously-identified QTLs, teat length appears to be an important trait in mastitis resistance. The RASGRP1 gene, overlapped by one QTL, is a candidate gene for mastitis resistance.