Study of genetic variability in pigs after the traditional breeding program

Molecular markers are tools used to improve genetic gains. The objective of this study was to analyze the security of alleles of molecular marker genes for characteristics of economic interest in a pure population of pigs. After the extraction of DNA from the hair of 272 Large White matrices, the allele and genotype frequency of single nucleotide polymorphism was performed using the ARMS-PCR Multiplex technique in the DGAT1, LEPR, H-FABP, MC4R, and SREBF1 genes using RFLP-PCR for the GH gene. After capillary electrophoresis in an automated DNA sequencing of the DGAT1, LEPR, H-FABP, and SREBF1 genes, no polymorphisms were found. Only the MC4R marker presented 100% heterozygosity. For the GH gene, 209 of the initial population samples were genotyped. The PCR product (605 bp) was digested with the restriction enzyme DdeI, with fragments being of 335, 148, and 122 bp for the D₁ allele and 457 and 148 bp for the D₂ allele. The genotypic frequency obtained of D₁D₂ was 88% and of D₂D₂ was 22%. The D₁ allele presented a frequency of 11% and the D₂ allele of 89%. The high intensity of selection for commercial breeds justifies the absence or the low number of polymorphisms for the genes studied.