Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/6/2004
Publication Date: 12/1/2004
Citation: Kneeland, J., Li, C., Basarab, J., Snelling, W.M., Benkel, B., Murdoch, B., Hansen, C., Moore, S.S. 2004. Identification and fine mapping of quantitative trait loci for growth traits on bovine chromosomes 2, 6, 14, 19, 21, and 23 within one commercial line of Bos taurus. Journal of Animal Science 82:3405-3414. Interpretive Summary: We report the identification and localization of chromosomal regions influencing birth weight, preweaning gain and postweaning gain in an Angus-based beef cattle seedstock line. One hundred seventy-six calves of twelve bulls were genotyped using 71 genetic markers from chromosomes 2, 6, 14, 19, 21, and 23. Sixteen combinations of adjacent markers were found to have significant associations with BWT, covering thirteen segments of the cattle genome. These segments were distributed across chromosomes 2 (two segments), 6 (three segments), 14 (three segments), 19 (one segment), 21 (two segments) and 23 (two segments). Thirteen marker combinations in seven segments, located on chromosomes 6 (two segments), 14 (one segment), 19 (one segment), 21 (one segment) and 23 (two segments) were associated with preweaning gain. Eleven marker combinations were associated with postweaning gain, located on chromosomes 2 (one segment), 6 (two segments), 14 (two segments), 19 (two segments), and 21 (one segment). By defining segments of the genome associated with cattle growth, we provide a resource for further investigation to identify genes within each region that affect growth, and develop DNA tests for genetic growth potential.
Technical Abstract: We report the identification and fine mapping of QTL for birth weight (BWT), preweaning ADG (PWADG), and postweaning ADG on feed (ADGF) in a commercial line of Bos taurus using an identical-by-descent haplotype sharing method. One hundred seventy-six calves of 12 bulls (9 to 30 male calves from each sire) of the Beefbooster, Inc., M1 line were typed using 71 genetic markers from bovine chromosomes (BTA) 2, 6, 14, 19, 21, and 23 (8 to 16 markers from each chromosome). Sixteen haplotypes were found to have significant (P < 0.05) associations with BWT at the comparison-wise threshold. The 16 haplotypes span 13 chromosomal regions, two on BTA 2 (9.1 to 22.5 cM and 95.0 to 100.3 cM), three on BTA 6 (8.2 to 11.8 cM, 35.5 to 49.7 cM, and 83.0 to 86.2 cM), three on BTA 14 (26.0 to 26.7 cM, 36.2 to 46.2 cM, and 52.0 to 67.7 cM), one on BTA 19 (52.0 to 52.7 cM), two on BTA 21 (9.9 to 20.4 cM and 28.2 to 46.1 cM), and two on BTA 23 (23.9 to 36.0 cM and 45.1 to 50.9 cM). Thirteen haplotypes spanning seven chromosomal regions significantly affected (P < 0.05) PWADG at the comparison-wise threshold. The seven chromosomal regions include two regions on BTA 6 (11.8 to 44.2 cM and 83.0 to 86.2 cM), one on BTA 14 (26.7 to 50.8 cM), one on BTA 19 (4.8 to 15.9 cM), one on BTA 21 (9.9 to 20.4 cM), and two on BTA 23 (17.3 to 36.0 cM and 45.1 to 50.9 cM). For ADGF, 11 haplotypes were identified to have significant associations (P < 0.05) at the comparison-wise threshold. The 11 haplotypes represented eight chromosomal regions, one on BTA 2 (9.1 to 22.5 cM), two on BTA 6 (49.7 to 50.1 cM and 59.6 to 63.6 cM), two on BTA 14 (17.0 to 24.0 cM and 36.2 to 46.2 cM), two on BTA 19 (52.0 to 52.7 cM and 65.1 to 65.7 cM), and one on BTA 21 (46.1 to 53.1 cM). The QTL regions identified and fine mapped in this study will provide a reference for future positional candidate gene research and marker-assisted selection of various growth traits.