Department of Animal Science, Faculty of Animal Science and Fisheries, Sari University of Agricultural Science and Natural Resources, Sari, Iran
Receive Date: 27 October 2012,
Revise Date: 17 January 2013,
Accept Date: 12 February 2013
Melatonin regulates some major physiological processes such as maturation and function of reproductive system, pubertal development, seasonal reproduction and adaptation. The activation of melatonin hormone is mediated by melatonin receptor. Previous studies showed melatonin receptor 1A gene (MTNR1A) is highly polymorphic in seasonally breeding species. The aim of the present study was detection of MTNR1Apolymorphism and its association with production (body weights at birth, 1, 3, 6, 9 and 12 month of age) and reproduction (litter size) traits in Zandi sheep using PCR-RFLP methodology. Hundred blood samples were randomly collected and genomic DNA was isolated using modified salting out method. A large fragment of exon 2 of MTNR1A gene was amplified by PCR using specific primer pairs. After amplification, the PCR product was digested with MnII endonuclease. Restricted digestion allowed the determination of two alleles (M, m) and two genotypes (MM, Mm) with frequencies of 0.91, 0.09 and 0.82, 0.18, respectively. Least square means showed that MM individuals had higher body weight at one month of age (BW1) than Mm individuals (P<0.05). No associations were found between observed genotypes and other studied traits.In the subsequent studies using a large number of samples along with the other important parameters such as sire effect and the lamb health status which may influence lamb body weight is recommended.
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