EN
The aim of this work was to search for a sequence polymorphism in the amelogenin gene (AMEL-X) in the region of exon 6. The material covered 653 cows and bulls of variable breeds, typical for their karyotype. The cows used in this study belong to Polish Red (150), Polish Whiteback (72), Red-and-White (72), Black-and-White with Holstein-Friesian blood share (69). The male material used in this study covered 269 sires (Black-and-White with Holstein-Friesian blood share - 125, Polish Red - 12, pure breed Holstein-Friesian - 67, Red-and-White - 30, Simmental - 27 and different meat breeds - 7). Six young bulls of Polish Whiteback and 15 young bulls of Polish Red were also tested. The polymerase chain reaction (PCR) primers used in this study were given by Ennis and Gallagher. The PCR products were separated on ABI PRISM 377 DNA sequencer (AB). For the AMEL-X gene copy the specific PCR product of 278bp was amplified and for the AMEL-Y gene copy the specific PCR product was 215bp long. This typical pattern was observed in cows and bulls of all tested cattle breeds except for the Polish Red. In addition to the typical signal for the chromosome X in 24 cows and 2 bulls of Polish Red a signal for the PCR product of 269bp was detected. This result shows that in an amplified region of AMEL gene in copy on chromosome X the sequence polymorphism is present and its molecular origin is a deletion of 9bp.