ARS | Publication request: GENOME SIGNATURES OF ARTIFICIAL SELECTION IN HOLSTEIN CATTLE

Submitted to: Cold Spring Harbor Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 25, 2009
Publication Date: May 7, 2009
Citation: Sonstegard, T.S., Ma, L., Cole, J.B., Van Tassell, C.P., Wiggans, G.R., Crooker, B.A., Garbe, J.R., Fahrenkrug, S.C., Mariani, B.D., Liu, G., Da, Y. 2009. GENOME SIGNATURES OF ARTIFICIAL SELECTION IN HOLSTEIN CATTLE. Cold Spring Harbor Meeting.

Technical Abstract: Artificial selection has been practiced for generations to enhance animal or plant species for specific desirable traits. However, very little is known at the molecular level about how intensive or prolonged selection affects genome sub-structure. Such investigations are typically limited by the availability of historic DNA to accurately measure allele frequency differences between marker genotypes in founder and contemporary populations. We compared genomic structure between selected and unselected cattle populations. The appeal of this model to identify signatures was potentiated by the unselected population being derived from Holstein cattle that had remained under neutral selection for 44 years. During this time, the breed has nearly doubled annual milk yield per cow through artificial selection. Analysis of approximately 50,000 SNP marker genotypes suggested an estimated 30% of the Holstein genome was affected by selection. To better discriminate these changes from random drift, selective sweep regions and SNP-phenotype associations were compared to identify six selection signatures associated with milk yield. Analysis of regions containing signatures for genes affecting both production and reproduction suggests selection for improved milk production at all of these loci has resulted in the enrichment for alleles that also reduce fertility. These results provide a framework to dissect the genetic networks underlying the phenotypic antagonism between production and fertility.