DETECTION OF ECONOMIC TRAIT LOCI IN THE US AND ISRAELI HOLSTEIN POPULATIONS WITH THE AID OF DNA MICROSATELLITES
RON, MICHA(1), Wayne Heyen(2), Moshe Band(1), Ester Feldmesser(1), Yang Da(3), George R. Wiggans(3), Paul M. VanRaden(3), Joel I. Weller(1), Harris A. Lewin(2)
1. Agricultural Research Organization, P.O.B. 6, Bet-Dagan,
Israel 50250, Israel
2. University of Illinois, Urbana, IL, USA
3. Agricultural Research Service, USDA, Beltsville, MD, USA
DNA microsatellites were used to detect loci affecting quantitative traits in the US dairy cattle population. Seventeen US Holstein families each with at least 29 progeny-tested sons were analyzed. The 17 grandsires and 1437 of their sons were genotyped for 32 genetic markers located on 19 of the 29 autosomes. From 16 to 204 sons were genotyped per family, and more than 100 sons were genotyped for six families. The sons' daughter yield deviations for milk, fat, and protein production, fat and protein percent, productive herd life, and somatic cell score were analyzed. The marker allele effect was significant at p<0.01 for four genetic markers. MGTG7 affected somatic cell score, and ILSTS28 affected protein percent. TGLA263 and CSSM66 had significant effects on more than one milk production trait, but the effects on fat percent were greatest for both loci. The effect of CSSM66 on chromosome 14 was significant at p<10-7. The within-family contrast for family 4 was 0.13%. Using both single-marker maximum likelihood and interval mapping with a second linked marker, BM302, the quantitative locus mapped adjacent to CSSM66. The estimated allele substitution effect was 0.46 phenotypic standard deviations, about 20% of the genetic variance or 10% of the phenotypic variance. 1498 daughters of seven Israeli sires were genotyped for CSSM66. The marker allele effect was only significant for fat percent at p<0.001. The within-family contrast was significant only for family 2 at p<0.0001, and the profile of effects and estimated map location was similar to that of US family 4. Thus, the same quantitative trait locus was detected in both populations.