ANNALES UNIVERSITATIS MARIAE CURIE-SK à ODOWSKA LUBLIN – POLONIA VOL. XXIX (4) SECTIO EE 2011 Department of Genetic and Animal Breeding, West Pomeranian University of Technology in Szczecin, Doktora Judyma 6, 71-460 Szczecin, email: jskorupski@zut.edu.pl JAKUB SKORUPSKI, MAREK KMIEû Detection of PRL/Alw21I polymorphism in ranch American mink (Neovison vison Schreb., 1777) Detekcja polimorfizmu PRL/Alw21I hodowlanej norki amerykaĔskiej (Neovison vison Schreb., 1777) Summary. The aim of the present study was to detect the prolactin gene polymorphism 5978 T/C (PRL/Alw21I) and to determine the genetic structure of the examined flock, in terms of the ana- lysed SNP. For this purpose, six breeds (Standard, Scanblack, Sapphire, Pearl, Black Cross and Sapphire Cross) of the ranch American mink (Neovison vison Schreb., 1777) were examined. Polymorphism 5978 T/C was detected in a fragment of the 3 rd intron, by PCR-ACRS-RFLP analy- sis (Alw21I restrictase was used). It was shown that there are two alleles – PRL T and PRL C and three genotypes – PRL T PRL T , PRL T PRL C , PRL C PRL C , according to recognized SNP. Genotyping of 165 individuals showed higher frequency (0.87) of the PRL T allele (highest in Sapphire minks, and lowest in Standard minks) and lower (0.13) of the PRL C allele. The percentage of individuals with PRL T PRL T genotype was equal 75.2%, with PRL T PRL C genotype – 26.3%, and with PRL C PRL C genotype – 1.2%. The obtained results suggest that the breeding work contributes to the elimination of PRL C allele from the gene pool of ranch minks and that strong selection pressure on 3 rd intron of prolactin gene occurred in Scanblack, Sapphire and Sapphire Cross breeds. Key words: American mink, ACRS-PCR-RFLP, genetic polymorphism, prolactin INTRODUCTION American mink (Neovison vison Schreb., 1777) is a popular fur-bearing animal, bred for its high-quality fur. Mink breeding is a good example of a traditional approach to animal husbandry, focusing on statistical analysis of the observed phenotypic variability. This variability is, in traditional approach, a resultant effect of genotype, environment and genotype-environment interactions, which are the basis for assessing the breeding value of the animal, which in turn is a criterion for selection [Nowicki et al. 1994, àu- kaszewicz 2007]. Although it explains the rules of inheritance of qualitative and quanti- tative traits, omits the genetic material structure and gene expression mechanisms [Walawski et al. 2004, àukaszewicz 2007].