Chromosomal deletion catalogue in dairy cattle facilitates the identification of lethal mutations

Genetic mutations are responsible for a substantial yearly-economic loss in the dairy industry. Mapping of such variants is essential for effective breeding planning and performance improvement.

2017.09.11 | Jette Odgaard Villemoes

Large genomic deletions are potential candidate for loss-of-function, which could be lethal as homozygote. Such genetic mutations are responsible for a substantial yearly-economic loss in the dairy industry. Mapping of such variants is essential for effective breeding planning and performance improvement. In this study, we have used a systematic approach for high-resolution structural variant mapping, genotyping, and validation from whole-genome sequence data in cattle, which is also of broader interest in livestock research. In the study, we identified about 8,500 large deletions; 82% of them are novel. These will be valuable information for the large scientific community working in gene mapping and genomic prediction in cattle. Our approach can identify the deletion breakpoints accurately; verified by both known deletions and new discovery. We have identified and confirmed a ~525 KB deletion on chromosome 23, causing stillbirth in cattle.

The highlights of the study are

  1. deletion-genotype could recapitulate genetic structure of populations,
  2. there are some highly differentiated genic and intergenic deletions among the populations,
  3. deletions in essential genes could only be observed in heterozygotes, while for nonessential genes, live homozygote individuals could be observed,
  4. natural gene knockouts are enriched for immune-related and olfactory receptor genes,
  5. deletions are highly enriched for health and fertility related QTL, while highly depleted for production traits and
  6. the knowledge of deletion breakpoints facilitates understanding of deletion formation mechanism.

The article has been published in the international journal DNA Research with the title Genome-wide mapping of large deletions and their population-genetic properties in dairy cattle


For more information, please contact

Md Mesbah Uddin
mesbah@mbg.au.dk - +4587157821

Goutam Sahana
goutam.sahana@mbg.au.dk - +4587157501

Department of Molecular Biology and Genetics
Aarhus University

Research