Effect of TGFB3 loci on phenotypic data and breeding value of body weight traits in Mazandaran native fowls

The transforming growth factor B (TGFB) subfamily is one of the most important groups of genes that are involved in development of growth and cell differentiation. In order to detect polymorphism in TGFB3 loci, blood samples were collected randomly from 160 breeder hens of Mazandarn native fowls breeding station. DNA was extracted using modified salting out method and a DNA fragment of 295 bp from TGFB3 loci was amplified (part of intron 3, exon 4 and small part of intron 4) using a specific primer pairs. The digested amplified fragment with BsiYI enzyme revealed two + and – alleles with the frequency of 0.8037 and 0.1961, respectively. The frequencies of "+/+", "+/-" and "-/-" genotypes were estimated at 0.6645, 0.2784 and 0.0569, respectively in studied population. The statistical analysis showed that the existence of one + allele in the genotypes significantly (P ≤ 0.05) increased the means of body weight at one day and eight week of age in comparison with "-/-" genotype which indicates the importance of this allele in body weight gain in chickens. It can be concluded that the studied marker site, together with the other documented variants in TGFB3 locus, can be very useful to obtain a better understanding of the genetic control of growth rate in chickens.