Isoenzyme Systems and Genotypes in Vendace (Coregonus Albula(Linnaeus, 1758)) from Lithuanian Lakes

Isoenzyme systems of vendace Coregonus albulafrom 18 lakes of Lithuania were studied. Muscle tissue homogenate was used for electrophoretic investigations on polyacrylamide gel. Six isoenzyme systems G3P, LDH, MDH, SOD, ME, EST and non-specific protein (NSP) were analysed. Seven polymorphic loci (Est-2, Est-3, Est-4, Est-5, Me-3, Nsp-2and Nsp-3) were selected for the genotype analysis of different vendace populations. Homozygotic genotypes were found to be dominant and a deficit of heterozygotic genotypes was detected in the majority of vendace populations. In addition, a significant difference between the observed and expected genotype frequencies at various loci was recorded. It has been thus concluded, that genetic instability is a characteristic of vendace populations in most of Lithuanian lakes.