Molecular Evaluation of the Myostatin Gene in Four Iranian Native Goat Breeds Did not Demonstrate any Association with Twining Rate

The objective of this study was to evaluate myostatin (MSTN) gene by polymerase chain reaction -restriction fragment length polymorphism (PCR-RFLP) and sequencing methods in four goat breeds including Mohabadi, Markhoz, Lori and Bital breeds. A573 bp fragment of MSTN gene was amplified by PCR. A new 5 bp deletion in 5`UTR (206TTTTA) of the MSTN gene was directly identified by sequencing. The AA and AB genotypes were observed in all above breeds, while the BB genotype was found only in Mohabadi breed. The AA genotype had the highest genotypic frequency in all breeds. On the other hand, the BB genotype in Mohabadi goat breed had the lowest genotypic frequency. The A allele frequency was higher than that of the B allele in the four breeds investigated in this study. The A allele frequency significantly differed between two (litter size) subgroups in Mohabadi breed. This difference in the allele frequency was not significant in Lori and Mohabadi breeds. Therefore, odds ratios statistics (ORs) showed no significant differences between genotypes for twining rate. Evaluation of MSTN gene 5`UTR region demonstrated the presence of two TATA boxes (important putative regulatory elements) which are located in the promoter region (position 32-36, 56-60) and one E-box (position 42-48) motifs. In conclusion, our results showed that the 5`UTR region polymorphism cannot be a key factor in the occurrence of twining in the above native goat breeds. It seems that more studies in large populations are needed to investigate the effect of MSTN gene on twining with more focus on other mutations in MSTN gene or other genes.