Lactose is the major carbohydrate of bovine milk and its concentration may be used as an indicator of udder health in cows. In fact, negative and moderate phenotypic and genetic correlations of lactose content with somatic cells and mastitis have been reported in literature. Besides, lactose content is more heritable than other milk traits, including somatic cells. Despite this, only few studies have explored the genes affecting lactose in cattle so far. Therefore, a genome-wide association study for lactose content was carried out using Austrian Fleckvieh bulls’ deregressed proofs, obtained in MiX99 software basing on 16 million test-day records. Following the conventional quality control, 40,964 SNPs (54k chip) in 2,854 bulls (estimated daughter contribution ≥10) were available for the association analysis in GEMMA software. After false discovery rate correction, 22 SNPs spread across the genome were found as significant. The highest P-value was found within the gene MFSD6 (BTA2, 5.757 Mb), known for its role in macrophages reception and intra/extra cellular transport facilitation. A variant at the end of BTA1 was within SH3BP5, a gene involved in white cells development and activity. One significant SNP was found within EFNA1 (BTA3), reported to regulate inflammatory response in udder of cows; moreover, variants were around 58 Mb on BTA20, region known to affect SCS/mastitis. Other signals were within and/or nearby genes related to transmembrane molecular transport (e.g. KCNK1, TFRC, RASGEF1C, LOC515333 and SLC35F3). The four most significant SNPs (P<5.05×10-07) explained 5% of the genetic variance; these results thus support that lactose content is a polygenic trait with a complex genetic architecture and affected by several genomic regions with small effect size.
Costa A., H. Schwarzenbacher, G. Mészáros, B. Fuerst-Waltl, C. Fuerst, J. Sölkner, et al. (2019). On the genomic regions affecting milk lactose content in dairy cattle. Wageningen Academic Publishers [10.3920/978-90-8686-890-2].
On the genomic regions affecting milk lactose content in dairy cattle
Costa A.
Primo
Membro del Collaboration Group
;
2019
Abstract
Lactose is the major carbohydrate of bovine milk and its concentration may be used as an indicator of udder health in cows. In fact, negative and moderate phenotypic and genetic correlations of lactose content with somatic cells and mastitis have been reported in literature. Besides, lactose content is more heritable than other milk traits, including somatic cells. Despite this, only few studies have explored the genes affecting lactose in cattle so far. Therefore, a genome-wide association study for lactose content was carried out using Austrian Fleckvieh bulls’ deregressed proofs, obtained in MiX99 software basing on 16 million test-day records. Following the conventional quality control, 40,964 SNPs (54k chip) in 2,854 bulls (estimated daughter contribution ≥10) were available for the association analysis in GEMMA software. After false discovery rate correction, 22 SNPs spread across the genome were found as significant. The highest P-value was found within the gene MFSD6 (BTA2, 5.757 Mb), known for its role in macrophages reception and intra/extra cellular transport facilitation. A variant at the end of BTA1 was within SH3BP5, a gene involved in white cells development and activity. One significant SNP was found within EFNA1 (BTA3), reported to regulate inflammatory response in udder of cows; moreover, variants were around 58 Mb on BTA20, region known to affect SCS/mastitis. Other signals were within and/or nearby genes related to transmembrane molecular transport (e.g. KCNK1, TFRC, RASGEF1C, LOC515333 and SLC35F3). The four most significant SNPs (P<5.05×10-07) explained 5% of the genetic variance; these results thus support that lactose content is a polygenic trait with a complex genetic architecture and affected by several genomic regions with small effect size.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.