Investigationof the Wnt10a and Wnt10b gene polymorphism in Afshari × Booroola Merino crossbred sheep

Selection of live animals with minimum carcass fat in animal breeding programs will lead to increase in meat production at national level. The ligands of Wnt genes are of the effective factors in adipocyte cell differentiation. This study was aimed to assess the association between polymorphisms in Wnt10a and Wnt10b genes and carcass traits in 96 Afshari – Booroola Merino male lambs. In this study, DNA was extracted from blood samples using phenol-chloroform extraction method and polymerase chain reaction was performed for amplification a 663 bp fragment of exon III and a part of the second intron of Wnt10a gene and a 512 bp fragment of exon III Wnt10b gene. The results showed a polymorphism and three monomorphisms (a different allele compared to reference sequence of the gene) in the Wnt10a gene but all the sequences of the Wnt10b fragment were the same in studied region of the gene. Results of the sequencing lead to identification of four single nucleotide changes in Wnt10a gene in the studied area when compared to the reference sequence. One of the monomorphisms was in the intron and among other three nucleotide changes identified in exon III one was a missense in codon 139. After digestion with restriction enzymes HpaII at this codon, it was observed that all sampled lambs had mutant homozygous genotype compared to the reference sequence. This site was also evaluated in a number of Afshari (fat- tailed) and Zell (with the least fat tail) but again the same results were observed. Therefore, it seems that in this position the G is the wild type allele in the studied population.