Genetic structure of the cisco (Coregonus albula L.) from lakes of glacial origin in northern Poland

European cisco (Coregonus albula L.) is one of the most precious species of the European lake ichtyofauna, however, due to progressive eutrophication of water, the range of its occurrence has decreased. Deteriorating ecological conditions are the main cause of this decline in population, and most of the existing populations in lakes are maintained thanks to reintroduction. Thus, it is important to determine the genetic structure of the European cisco. The study involved PCR-RFLP-based genetic analysis of C. albula caught in 15 lakes in northern Poland, including four lakes located in national parks. The analysis covered 3 genes located in the mitochondrial DNA: ND1, ND3/4 and cytochrome b, as well as a control region (D-loop). The PCR product was digested with 4 endonucleases (RsaI, MspI, BsuI and HhaI) and the resulting haplotypes were grouped into combinations. Statistical analysis were then performed on these groups. Based on the genetic distance, a phenogram was constructed in which two groups could be distinguished. One group was represented by C. albula populations from most lakes in north-western Poland, including the three protected lakes. The other group consisted of the European cisco population from Lake Wigry (north-eastern Poland) and commercially exploited lakes from the southern part of the investigated north-western Poland area. The results of the study of C. albula from northern Poland present a valuable molecular characterization of the populations and can be a starting point for further genetic monitoring.