|Smith, Timothy - Tim|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2009
Publication Date: 6/1/2009
Citation: Alexander, L.J., Kuehn, L.A., Smith, T.P., Matukumalli, L.K., Mote, B., Koltes, J.E., Reecy, J., Geary, T.W., Rule, D.C., Macneil, M.D. 2009. A Limousin specific myostatin allele affects longissimus muscle area and fatty acid profiles in a Wagyu-Limousin F*2* population. Journal of Animal Science 87:1576-1581. Interpretive Summary: Seventy single nucleotide polymorphism markers (SNPs) were used to scan the centromeric portion of chromosome 2 of 328 F*2* progeny in a Wagyu (Jamanese Black) x Limousin cross for straits associated with rib-eye area, lipid deposition, composition and palability of meat. We have confirmed the results of our previous study for a number of traits. The study presented here may lead to a better understanding of genetic differences between the Wagyu and Limousin breeds.
Technical Abstract: A microsatellite-based genome scan of a Wagyu x Limousin F2 cross population previously demonstrated QTL affecting longissimus muscle area (LMA) and fatty acid composition were present in regions near the centromere of BTA 2. In this study we used 70 SNP markers to examine the centromeric 20 megabases of BTA 2, including the Limousin specific F94L myostatin allele (AB076403.1; 415C>A) located at approximately 6 megabases on the draft genome sequence of BTA2, A significant effect of the F94L marker was observed (F= 60.17) for LMA, which indicated that myostatin is most likely responsible for the effect. This is consistent with previous reports that the substitution of Leu for Phe at amino acid 94 of myostatin (caused by the 415C>A transversion) is associated with increased muscle growth. Surprisingly, several fatty acid trait QTL, which affected the amount of unsaturated fats, also mapped to or very near to the myostatin marker, including the ratio of C16:1 MUFA to C16:0 saturated fat (F = 16.72), C18:1 to C18:0 (F = 18.88) and total content of MUFA (F = 17.12). In addition, QTL for extent of marbling (F = 14.73) approached significance (P = 0.05) and CLA level (F = 9.22) was marginally significant (P = 0.18). We also observed associations of SNP located at 16.3 Mb with kidney, pelvic and heart fat (F = 15.00) and for the amount of SFA (F = 12.01). These results provide insight into genetic differences between the Wagyu and Limousin breeds and may lead to a better tasting and healthier product for consumers through improved selection for lipid content of beef.