International Science Index


Identification of 332G>A Polymorphism in Exon 3 of the Leptin Gene and Partially Effects on Body Size and Tail Dimension in Sanjabi Sheep


The objective of the present study was to determine the polymorphism in the leptin (332G>A) and its association with biometric traits in Sanjabi sheep. For this purpose, blood samples from 96 rams were taken, and tail length, width tail, circumference tail, body length, body width, and height were simultaneously recorded. PCR was performed using specific primer to amplify 463 bp fragment including exon 3 of leptin gene, and PCR products were digested by Cail restriction enzymes. The 332G>A (at 332th nucleotide of exon 3 leptin gene) that caused an amino acid change from Arg to Gln was detected by Cail (CAGNNNCTG) endonuclease, as the endonuclease cannot cut this region if G nucleotide is located in this position. Three genotypes including GG (463), GA (463, 360and 103 bp) and GG (360 bp and 103 bp) were identified after digestion by enzyme. The estimated frequencies of three genotypes including GG, GA, and AA for 332G>A locus were 0.68, 0.29 and 0.03 and those were 0.18 and 0.82 for A and G alleles, respectively. In the current study, chi-square test indicated that 332G>A positions did not deviate from the Hardy–Weinberg (HW) equilibrium. The most important reason to show HW equation was that samples used in this study belong to three large local herds with a traditional breeding system having random mating and without selection. Shannon index amount was calculated which represent an average genetic variation in Sanjabi rams. Also, heterozygosity estimated by Nei index indicated that genetic diversity of mutation in the leptin gene is moderate. Leptin gene polymorphism in the 332G>A had significant effect on body length (P<0.05) trait, and individuals with GA genotype had significantly the higher body length compared to other individuals. Although animals with GA genotype had higher body width, this difference was not statistically significant (P>0.05). This non-synonymous SNP resulted in different amino acid changes at codon positions111(R/Q). As leptin activity is localized, at least in part, in domains between amino acid residues 106-1406, it is speculated that the detected SNP at position 332 may affect the activity of leptin and may lead to different biological functions. Based to our results, due to significant effect of leptin gene polymorphism on body size traits, this gene may be used a candidate gene for improving these traits.

[1] W. Sousa, E. Brito, A. Medeiros, F. Q. Cartaxo, M. F. Cezar, M. d. G.G. Cunha, ،،Características morfométricas e de carcaça de cabritos e cordeiros terminados em confinamento,,, Revista Brasileira de Zootecnia, vol .38. pp 1340-6, 2009
[2] A. Mandal, R. Roy, P. Rout, ،،Direct and maternal effects for body measurements at birth and weaning in Muzaffarnagari sheep of India,,, Small Ruminant Research, vol. 75, pp.123-7, 2008.
[3] A. Salako, ،،Application of morphological indices in the assessment of type and function in sheep, ,,Int J Morphol. vol .24 pp .13-8. 2006.
[4] I. Mohammed, J. Amin, ،،Estimating body weight from morphometric measurements of Sahel (Borno White) goats, ,,Small Ruminant Research.
[5] S. Bote, S. Basu ،،Relationship between body measurements and meat production in Beetal goats,,, Indian veterinary journal. 1984.
[6] N. Okeudo, B. Moss, ،، Interrelationships amongst carcass and meat quality characteristics of sheep,,, Meat science. vol .69. pp .1-8. 2005.
[7] T. Field, ،،The marketing system. Beef production and management,,, decisions 5th ed Prentice Hall, New York, NY. pp. 245-99. 2007.
[8] A. H. Radhi, H. M. A. Al-Tayy, M. B. S. Al-Shuhaib, A. L. Dagher, ،،Correlation between Leptin Encoding Gene and Some Haematological and Biochemical Parameters in Awassi Sheep,,,
[9] R. Barzehkar, A. Salehi, F. Mahjoubi, ،،Polymorphisms of the ovine leptin gene and its association with growth and carcass traits in three Iranian sheep breeds,,, Iranian Journal of Biotechnology. vol. 7. pp .241-6. 2009.
[10] D. Yang, H. Chen, X. Wang, Z. Tian, L. Tang, Z. Zhang et al. ،،Association of polymorphisms of leptin gene with body weight and body sizes indexes in Chinese indigenous cattle,,, Journal of Genetics and Genomics. vol. 34. pp .400-5. 2007.
[11] A. H. Mahmoud, A. A. S, F. M A-t, T. M S, M. A. A. ،،Nucleotide sequence polymorphism within exon 3 region of leptin and prolactin genes in Herri sheep,,, Research Journal of Biotechnology. vol .9. pp. 69-72. 2014.
[12] J. Tavakolian, ،،An introduction to genetic resources of native farm animals in Iran,,, Animal Science Genetic Research Institute Press, Tehran, Iran. 2000.
[13] B. Solimani, B. Chaharaein, R. Rahbar, V. Hemmati,،،Genetic Diversity of Sanjabi Sheep Inferred from Microsatellite Markers and Their Association with Fecundity and Body Weight Traits,,, Research Journal of Animal Sciences. pp .34-9. 2011.
[14] M. Tahmoorespur, A. Taheri, M.V. Valeh, D. A. Saghi, M. Ansary, ،،Assessment relationship between leptin and ghrelin genes polymorphisms and estimated breeding values (EBVs) of growth traits in Baluchi sheep,, Journal of Animal and veterinary Advances. vol. 9. pp. 2460-5. 2010
[15] A. Hashemi, K. Mardani, M. Farhadian, I. Ashrafi, M. Ranjbari, ،،Allelic polymorphism of Makoei sheep leptin gene identified by polymerase chain reaction and single strand conformation polymorphism,,, African Journal of Biotechnology, vol .10. pp .17903-6. 2011.
[16] A. Hajihosseinlo, A. Hashemi, S. Sadeghi, ،، Association between polymorphism in exon 3 of leptin gene and growth traits in the Makooei sheep of Iran,,, Livestock Research for Rural Development, vol 24. pp .543-6. 2012
[17] S. Gizaw, H. Komen, J.A. van Arendonk, ،،Selection on linear size traits to improve live weight in Menz sheep under nucleus and village breeding programs,,, Livestock science, vol. 118. pp. 92-8. 2008.
[18] A. Yilmaz, M. Davis, H. Hines, ،، A PCR-SSCP polymorphism detected in the 5 flanking regions of the ovine IGF1 gene,,, Research and reviews: beef and sheep. Special Circular. vol .5. pp .170-99. 2000.
[19] S. Moore, C. Li, J. Basarab, W. Snelling, J. Kneeland, B. Murdoch, et al. ،،Fine mapping of quantitative trait loci and assessment of positional candidate genes for backfat on bovine chromosome 14 in a commercial line of,,,. Journal of animal science. vol .81. pp. 1919-25. 2003
[20] G. Thaller, C. Kühn, A. Winter, G. Ewald, O. Bellmann, J. Wegner, et al. ،،DGAT1, a new positional and functional candidate gene for intramuscular fat deposition in cattle,,, Animal genetics, vol. 34. pp .354-7. 2003.
[21] J. M. Akey, ،،Constructing genomic maps of positive selection in humans,,, Genome research, vol .19. pp .711-22. 2009.
[22] Y. Ohshiro, K. Ueda, M. Nishi, M. Ishigame, H. Wakasaki, H. Kawashima, et al. ،،A polymorphic marker in the leptin gene associated with Japanese morbid obesity,,, Journal of molecular medicine. vol .78 pp .516-20. 2000
[23] M. Shojaei, M. M. Abadi, M. A. Fozi, O. Dayani, A. Khezri, ،،Association of growth trait and Leptin gene polymorphism in Kermani sheep,,, Journal of Cell and Molecular Research, Citeseer. 2010.
[24] L. Zwierzchowski, J. Oprzadek, E. Dymnicki, P. Dzierzbicki,،، An association of growth hormone, kappa-casein, beta-lactoglobulin, leptin and Pit-1 loci polymorphism with growth rate and carcass traits in beef cattle,,, Animal Science Papers and Reports, vol. 19. pp. 65-77. 2001.
[25] C. J. Fitzsimmons, S. M. Schmutz, R. D. Bergen, J. J. McKinnon. ،،A potential association between the BM 1500 microsatellite and fat deposition in beef cattle,,, Mammalian Genome. vol .9. pp. 432-4. 1998.
[26] R. Lagonigro, P. Wiener, F. Pilla, J. Woolliams, J. Williams, ،،A new mutation in the coding region of the bovine leptin gene associated with feed intake,,, Animal Genetics. vol .34 pp .371-4. 2003
[27] Z.H. Jiang, J. P. Gibson, ،،Genetic polymorphisms in the leptin gene and their association with fatness in four pig breeds. Mammalian Genome,,, vol. 10. pp .191-3. 1999
[28] F. Xi, N. Li, G. Cao, Y. Zhao, C. Wu,،، RFLPS polymorphic analysis on Obese (ob) gene locus in swine,,, Journal of agricultural biotechnology. vol. 8. pp. 123-4. 1999.
[29] M. Negahdary, S. Majdi, P. Biabani, A. Hajihosseinlo, ،،Relationship of TNF-αGene Polymorphism with fat-tail Measurements (fat-tail dimensions (and wool weights in fat-tail Makooei breed of Iranian sheep,,, 2014.