مطالعه ژن‌های کاندیدا مؤثر بر صفات دنبه در محدوده مشخصی از کروموزوم شماره 5 در گوسفندان لری بختیاری و زل با روش PCR-SSCP

     Meat quality and carcass composition are the most important economic traits in sheep. Body fat and fat-tail are key factors affecting carcass quality and meat production in each breed, and mutations in sequences of the genes that control these traits can affect the animal performance and therefore the breeding value. The aim of this study was to investigate the polymorphism in some regions of SAR1B, SEC24A and VDAC1 genes in candidate genomic regions for fat traits on ovine chromosome 5. Blood samples were collected randomly from 300 Lori-Bakhtiari and 100 Mazandaran sheep and DNA was extracted using modified salting out method. Polymerase chain reaction (PCR) was performed for amplification of 478, 579 and 348 bp fragments of studied genes using specific primer pairs and genotyping of samples was done by SSCP technique. The obtained results showed three banding patterns of A, B and C for SAR1B marker site in Lori-Bakhtiari sheep but it was monomorph in Zel sheep. For SEC24 gene, three banding patterns of A, B and C were observed in both sheep breeds, but VDAC1 was monomorph in both sheep breed. The effect of banding patterns of SAR1B gene on fat-tail characteristics were significant (P<0.001), so that the A banding pattern showed highest measurement of the upper and lower, height and weight of fat-tail. The band patterns of SEC24A gene significantly associated with fat-tail characteristics, and banding pattern of B showed highest values. Considering the monomorphic pattern of SAR1B gene in Zel sheep and polymorphic pattern in fat-tailed Lori-Bakhtiary sheep, and also polyomorphic patterns of SEC24A gene in both breeds, these two marker site could be considered as potential candidate genes affecting fat tail characteristic in fat-tailed sheep breeds. More studies on different parts of these genes (exon, intron, regulatory regions) and their association with fat-tail traits is recommended for confirmation if the results.