Associação genômica ampla aplicada a variáveis de carcaça em ovinos Santa Inês.

Abstract

Primal carcass cuts such as loin, leg, shoulder, and rib directly affect the commercial value of the sheep carcass. Thus, this study aimed to carry out a genome wide association study (GWAS) for primal cuts yields in Santa Inês sheep. A total of 491 lambs were genotyped with the Illumina Ovine SNP50 BeadChip and recorded for the shoulder, rib, loin, and leg yields. After the quality control, 490 individuals and 44,996 markers were used in GWAS analysis, using the WssGBLUB method. The estimates of heritability were 0.28 ± 0.004 (Loin), 0.32 ± 0.003 (Shoulder), 0.41 ± 0.001 (Rib), and 0.46 ± 0.006 (Leg). A total of 38 genomic windows explained >1% of additive genetic variance (VA) of primal cuts, which were located in the chromosomes OAR1, 2, 3, 4, 6, 7, 8, 9, 18, 20, 22, 24, and 26 were found. The VA explained were 13.1% (Leg), 18.8% (Shoulder), 19.2% (Loin), and 20.1% (Rib). The four main GW peaks were found on OAR1_36252750:37221480, explaining 6.4% of VA for rib yield, OAR8_ 14238752:15227417, explaining 5.1% of VA for shoulder yield, OAR18 _60775598:61772991, explaining 5.8% of VA for loin yield, and OAR20_ 18853816:19834355 explaining 2.6% of VA for leg yield. 307 protein coding genes were found, being 69, 61, 89, and 88 genes in the GWS for loin, rib, shoulder, and leg yields, respectively. Functional annotation analysis was carried out for these protein-coding genes, which found the neuroactive ligand-receptor interaction pathway as the only one significant pathway (P-value = 2.0E-7). Top five candidate genes were as follows: VEGFA, FGFR1, SLC2A1, TRND, and MIR29A, which has a key role in muscle growth. Further studies involving sequencing of these genes may be performed to identify the causal variants for the primal cut yields.