A directed search around caprine candidate loci provided evidence for microsatellites linkage to growth and cashmere yield in Rayini goats

Four genomic regions located on goat chromosomes 1, 2, 5 and 13 previously reported as significant DNA regions harboring quantitative trait loci (QTL) for growth and fleece traits in goat were considered as candidate genomic regions. The objective of conducting this study was to determine whether there is evidence for association of growth traits and cashmere yield in native Iranian Rayini goats with markers flanking these candidate regions. One hundred and twenty kids from 6 Rayini bucks (20 half-sib offspring per buck) were used in the present study. The six bucks and their offspring were genotyped for eight microsatellite markers flanking the candidate intervals. Body weights recorded on the kids were birth weight (BW0), weaning weight (BW3) and weight at 6 months of age (BW6). Average daily gains from birth to weaning and weaning to 6 months of age were computed based on the values obtained for BWO, BW3 and BW6. Cashmere yield was also recorded for the kids at the first, second and third year of age. QTL analysis in the candidate intervals was conducted using the least squared regression interval mapping approach. Linkage analysis indicated significant QTL for growth traits on goat chromosomes 1, 2 and 5 (chromosome-wide significance of P<0.01). Three of the candidate regions located on chromosomes 2, 5 and 13 were linked to cashmere yield. QTL effect ranged from 0.8 to 4.3 in units of residual standard deviation for different traits and families. (C) 2008 Elsevier B.V. All rights reserved.