Detection of three major chromosome regions involved in the arrival to puberty in bulls through genome-wide association

FERNÁNDEZ ME; LIRÓN JP; PRANDO AJ; ROGBERG MUÑOZ A; BALDO A; GIOVAMBATTISTA G

Cairns

Congreso; 33 Conference for Animal Genetics; 2012

International Society for Animal Genetics

In bovine, there are significant differences, among and within breeds, in time when bulls reach puberty. The objective of this work was to perform a genome-wide association study using a selective DNA approach for identification of genetic markers associated with age at puberty. Two-hundred-seventy-six Angus males were weighted and scrotal circumference measured every month. When first bull calves reached 26 cm of SC, sperm quality was added to the monthly measurements for the next three months. Based on sperm quality, two groups, corresponding to the top and bottom 6.5% of the phenotypic distribution, were chosen. These samples were genotyping with the Illumina BovineHD Genotyping BeadChip. The number of associated SNP at 0.001 significance thresholds was 265, among which six were significant at 0.0001. These significant associated markers were located majorly in five chromosome regions: BTA3 (30.57% of associated SNPs), BTA24 (29.43%), and BTA1, 16 and 20 (23.77%). Fifteen additional chromosomes only had few associated SNPs, while the remaining ten chromosomes did not exhibit significant associated markers. SNPs located into the BTA3, 20 and 24 associated regions were validated in the whole sample using pyrosequencing methods. The results obtained here will be useful for further identification of causative mutations and functional studies.