Search bioRxiv⌕ Search

Biology subjects

Richardson, I. W.

Publications and source records attributed to Richardson, I. W..

2 recordsLinked to original sources

A Population Genomics Analysis of the Native Irish Galway Sheep Breed

The Galway sheep population is the only native Irish sheep breed and represents an important livestock genetic resource, which is currently categorised as \"at-risk\". In the present study, comparative population genomics analyses of Galway sheep and other sheep populations of European origin were used to investigate the microevolution and recent genetic history of the breed. These analyses support the hypothesis that British Leicester sheep were used in the formation of the Galway breed and suggest more recent gene flow from the Suffolk sheep breed. When compared to conventional and endangered breeds, the Galway breed was intermediate in effective population size, genomic inbreeding and runs of homozygosity. This indicates that, although the Galway breed is declining, it is still relatively genetically diverse and that conservation and management plans informed by genomic information may aid its recovery. The Galway breed also exhibited distinct genomic signatures of artificial or natural selection when compared to other breeds, which highlighted candidate genes that may be involved in meat and wool production.

genomics↗

Genomic characterisation and conservation genetics of the indigenous Irish Kerry cattle breed

Kerry cattle are an endangered landrace heritage breed of cultural importance to Ireland. In the present study we have used genome-wide SNP data (Illumina(R) BovineSNP50 array) to evaluate genomic diversity within the Kerry cattle population and between Kerry cattle and other European cattle breeds. Visualisation of patterns of genetic differentiation and gene flow among cattle breeds using phylogenetic trees with ancestry graphs highlighted, in particular, historical gene flow from the British Shorthorn breed into the ancestral population of modern Kerry cattle. Principal component analysis (PCA) and genetic clustering emphasised the genetic distinctiveness of Kerry cattle relative to comparator British and European cattle breeds. Modelling of genetic effective population size (Ne) revealed a demographic trend of diminishing Ne over time and that recent estimated Ne values for the Kerry breed may be less than the threshold for sustainable genetic conservation. In addition, analysis of genome-wide autozygosity (FROH) showed that genomic inbreeding has increased significantly during the 20 years between 1992 and 2012. Finally, signatures of selection revealed genomic regions subject to natural and artificial selection as Kerry cattle adapted to the climate, physical geography and agro-ecology of southwest Ireland.\n\nNote 1: This is an Associate Editor (D.E.M) Inaugural Article submission to Frontiers in Genetics: Livestock Genomics\n\nNote 2: British English language style preferred for publication of this article.

genomics↗