|Olson, Timothy - UNIVERSITY OF FLORIDA|
|Johnson, Dwain - UNIVERSITY OF FLORIDA|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 27, 2004
Publication Date: January 3, 2005
Citation: Casas, E., White, S.N., Riley, D.G., Smith, T.P., Brenneman, R.A., Olson, T.A., Johnson, D.D., Coleman, S.W., Bennett, G.L., Chase, C.C. 2005. Assessment of single nucleotide polymorphisms in genes residing on chromosomes 14 and 29 for association with carcass composition traits in bos indicus cattle. Journal of Animal Science. 83:13-19. Interpretive Summary: Genetic markers developed for cattle from temperate climate (Bos taurus) were assessed in a population of tropically adapted cattle (Bos indicus). These genetic markers have been associated with marbling and meat tenderness. No association was found between the genetic markers or any of the growth and carcass traits evaluated. These results clearly show that association between genetic markers and traits of economical importance observed in Bos taurus cattle should not be extrapolated to Bos indicus cattle without verification. If genetic markers are to be used in Bos indicus cattle, appropriate markers may need to be developed.
Technical Abstract: The objective was to assess the association of single nucleotide polymorphisms at the diacylglycerol O-acyltransferase 1 (DGAT1), Thyroglobulin (TG), and micromolar calcium activated neutral protease (CAPN1) genes with carcass composition and meat quality traits in Bos indicus cattle. A population of Brahman calves (n = 479) was developed in central Florida from 1996 to 2000. Traits analyzed were average daily gain, hip height, slaughter weight, fat thickness, hot carcass weight, marbling score, loin muscle area, estimated kidney, pelvic and heart fat, yield grade, retail yield, sensory panel tenderness score, hump height, and cooked meat tenderness measured as Warner-Bratzler shear force at 7 d, 14 d, and 21 d postmortem. Single nucleotide polymorphisms previously reported in the TG and DGAT1 genes were used as markers on chromosome 14. Two previously reported and two new single nucleotide polymorphisms in the CAPN1 gene were used as markers on chromosome 29. One single nucleotide polymorphism in CAPN1 was uninformative, and another one was associated with tenderness score (P < 0.05), suggesting the presence of variation affecting meat tenderness. All three informative single nucleotide polymorphisms at the CAPN1 gene were associated with hump height (P < 0.02). The TG marker was associated with fat thickness and loin muscle area (P < 0.05), but not with marbling score (P > 0.05). No significant associations (P > 0.05) of the single nucleotide polymorphisms in the DGAT1 gene were observed for any trait. Allele frequencies of the single nucleotide polymorphisms in TG and CAPN1 were different in this Brahman population compared to reported allele frequencies in Bos taurus populations. The results suggest that the application of molecular marker data developed in Bos taurus populations to Bos indicus populations may require development of appropriate additional markers.