Polymorphism of the Gonadotropin‐Releasing Hormone Receptor Gene and Its Association With Production Traits in Isfahani Native Hens

BACKGROUND: Gonadotropins are glycoprotein hormones that are often secreted from the gonadotrope cells of the pituitary gland. These hormones play an essential role in growth, reproduction and sexual function. AIMS: Therefore, this research was conducted to identify genetic polymorphisms of the Gonadotropin-Releasing Hormone Receptor (GnRHR) gene on Isfahan native hen traits and their relationship with production traits. MATERIALS & METHODS: For this purpose, blood was taken from 100 Isfahan native hens that were randomly selected from the Isfahan native hen centre. DNA was extracted by the phenol-chloroform method. Then, using the designed primers, the target fragment was amplified and directly sequenced. The sequences were blasted with the reference gene in NCBI. After analysing the sequences, the relationship between genotypes and traits was investigated. RESULTS: The results showed that five single-nucleotide polymorphisms in gene GNRHR were observed. These polymorphisms were located in nucleotides numbers 117, 123, 157, 453 and 550 of the amplified fragments and caused the change of nucleotide T to C, C to T, C to T, C to T and A to G, respectively. According to the results, the GnRHR gene has an acceptable effect on the productive traits of Isfahan native hens. Of course, its effect cannot be considered important for the entire production traits, but in the sexual maturity sections, the number of eggs plays an important role and has a significant effect on the mentioned production traits. CONCLUSION: These results show that the observed nucleotide changes if confirmed in other relevant studies can be used in the trait selection programme with the help of markers.