The phenotypic traits of high prolificacy, low fat on the rib eye muscle and high tolerance to internal parasites make the Barbados Blackbelly （BBB） sheep a valuable economic resource for small subsistence farmers o...The phenotypic traits of high prolificacy, low fat on the rib eye muscle and high tolerance to internal parasites make the Barbados Blackbelly （BBB） sheep a valuable economic resource for small subsistence farmers on some Caribbean islands. However, the determination of what is a purebred BBB sheep has long been a contentious issue because of the subjectivity. It is therefore necessary to have a more reliable means of identifying what is a purebred BBB sheep for purposes of conservation and breed improvement. Three geographically isolated populations of BBB sheep were genetically analysed at 19 microsatellite loci. Eighteen of the microsatellites were found to be useful for genetic analysis of the BBB sheep, based on polymorphic information content （PIC） values （0.5 〈 PIC 〉 0.25）. One microsatellite was not useful for genetic analysis based on PIC （0.111）, however it is considered to be a locus of interest because it is fully inbred （f = 1） and homozygous in all of the populations analysed. The analysis also showed that the purebred population of BBB sheep can be distinguished from other populations by formation of distinct clusters when subjected to analysis of molecular variance （AMOVA） and the construction of a rooted consensus tree using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships.展开更多
文摘The phenotypic traits of high prolificacy, low fat on the rib eye muscle and high tolerance to internal parasites make the Barbados Blackbelly （BBB） sheep a valuable economic resource for small subsistence farmers on some Caribbean islands. However, the determination of what is a purebred BBB sheep has long been a contentious issue because of the subjectivity. It is therefore necessary to have a more reliable means of identifying what is a purebred BBB sheep for purposes of conservation and breed improvement. Three geographically isolated populations of BBB sheep were genetically analysed at 19 microsatellite loci. Eighteen of the microsatellites were found to be useful for genetic analysis of the BBB sheep, based on polymorphic information content （PIC） values （0.5 〈 PIC 〉 0.25）. One microsatellite was not useful for genetic analysis based on PIC （0.111）, however it is considered to be a locus of interest because it is fully inbred （f = 1） and homozygous in all of the populations analysed. The analysis also showed that the purebred population of BBB sheep can be distinguished from other populations by formation of distinct clusters when subjected to analysis of molecular variance （AMOVA） and the construction of a rooted consensus tree using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships.
