Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2007.4291.4294RohallahAlinaghizadeh MohammadrezaMohammad AbadiShahinMoradnasab Badrabadi1220071023In cattle, caseins are subdivided into four main groups: αS1-, αS2-, β- and k-caseins. k-caseins (CSN2) considerably differ from other caseins in structure and other properties. Testing the A and B alleles is of practical importance, because the milk of cows that carry the B allele of CSN3 has a better thermal resistance and shorter coagulation time, better curdles and contains micelles of different sizes. Iranian Sistani cattle (Bos indicus) are a heavy built breed and used as dual-purpose cattle breed in Eastern Iran. This breed is a genetic resource that shows special features of adaptation to rustic environments. One of the most distinctive features of Sistani cattle is its great capability to resist diseases which makes it a potential reservoir of germplasm useful for future crosses. Our main goal was to study DNA-polymorphism of the CSN3 gene in the Iranian Sistani native cattle (Bos indicus) and analyze the information value of CSN3 gene polymorphism as a genetic marker. We genotyped and analyzed 65 animals of this breed using PCR-RFLP. The frequencies of A and B alleles were 0.6385 and 0.3615 and those of AA, AB and BB genotypes were 0.4000, 0.4769 and 0.1231, respectively. In the Sistani Zebu breed, frequency of B allele is higher than other Zebu breeds, indicating that intensive selection for dairy production have been done and indirectly influenced CSN3 allele frequencies.]]>Alipanah, M., L. Klashnikova and G. Rodionov,20073191194Boom, R., C.J. Sol, M.M. Salimans, C.L. Jansen, P.M. Wertheim-van Dillen and J. van der Noordaa,199028495503Bovenhuis, H., J.A.M. Van Arendonk and S. Korver,19927525492559Denicourt, D., M.P. Sabourand and A. McAllister,19901215216Fernando, H.B., A.D.V. Garnero, L.A.F. Bezarra, A.J.M. Rosa, R.B. Lobb and L. Martelli,2005288487Ferretti, L., P. Leone and V. Sgaramella,19901868296833Gladyr, E.A., N.A. Zinoveva, N.S. Marzanov and G. Brem,20002000pp: 8688Kalashnikova, L.A., N.A. Strelkova and E.P. Golubina,20022002pp: 137138Kaminski, S.,199637179196Kemenes, P.A., L.C.A. Regitano, A.J.M. Rosa, I.U. Paker and A.G. Razook et al.,199922539541Levene, H.,1949209194Nei, M.,19737033213323Pedersen, J.,1991108434445Prinzenberg, E.M., I. Krause and G. Erhardt,1999CSN3 locus discriminates six alleles corresponding to known protein variants (A, B, C, E, F and G) and three new DNA polymorphisms (H, I, A(1)).]]>104962Pudovkin, A.I., D.V. Zaykin and D. Hedgecock,1996144383387Schlieben, S., G. Erhardt and B. Senft,199122333342StatSoft,19961996Sulimova, G.E., S.S. Sokolova and O.P. Semikozova,1992261826Sulimova, G.E., N.Y. Badagueva and I.G. Udina,19963213711377Sulimova, G.E.,199834465467Sulimova, G.E., M. Ahani-Azari, J. Rostamzadeh, M.R. Mohammad Abadi and O.E. Lazebny,2007437379Yeh, F.C., R.C. Yang and T. Boyle,19991999Zakizadeh, S., A. Nejati-Javaremi, M. Reissmann, G. Rahimi and A. Jahan Bakhshi,200710941945