Polymorphisms of candidate genes associated with meat quality and disease resistance in indigenous and exotic pig breeds of Vietnam
The objectives of this study were to analyse genotype distribution and sequence variations of candidate genes putatively associated with meat quality and disease resistance in exotic and indigenous Vietnamese pig breeds. For this purpose, 340 pigs from four indigenous and two exotic breeds were included in the analysis of the polymorphisms of the heart fatty-acid-binding protein (H-FABP), alpha 1 fucosyltransferase (FUT1), and bactericidal/permeability-increasing protein (BPI) genes by the sequencing and PCR-RFLP methods. For H-FABP, 17 single nucleotide polymorphisms (SNPs) were detected in indigenous pig breeds by direct sequencing of a fragment at intron 2 of the H-FABP gene. The mutation T1556C created a new restriction site for the enzyme MspI, which gave rise to new allelic variants in three indigenous pig breeds. In indigenous breeds, the frequency of the favourable alleles a and d at MspI and HaeIII sites of the H-FABP gene were low. Meanwhile, the frequency of the d allele at the HaeIII site in exotic breeds was significantly higher than those of indigenous pig breeds. No mutation was found in the RFLP-fragment of the FUT1 gene of four indigenous pig breeds by sequencing, while in the BPI gene two mutations were detected in the Tap Na breed. The resistant alleles of the FUT1 and BPI genes in the exotic breeds were significantly higher than those of indigenous pig breeds. Among the indigenous pig breeds, the Tap Na breed possessed a higher frequency of the resistant allele G of BPI gene than the remaining breeds. The T1556C mutation at H-FABP may be important for the genetic improvement of intramuscular fat content and breed. Tap Na may be a source of resistant alleles for local ecologies.
Keywords: H-FABP gene, FUT1 gene, BPI gene, IMF, PCR-RFLP