Conventional and molecular cytogenetics of the pikeperch (Sander lucioperca L.)



Pikeperch (Sander lucioperca L.) is a percid fish species of high commercial value and potential for being aquacultured in Europe. As such, pikeperch needs to be karyologically studied with special attention dedicated to arrangement of the homologous chromosomes into pairs and chromosomal location of the chosen DNA sequences. The karyotype of the pikeperch consists of 48 small chromosomes: One pair of metacentric chromosomes, 15 pairs of submetacentric chromosomes and eight pairs of subtelo-acrocentric chromosomes (FN = 80). Original data on the chromosomal distribution of early and late replication regions, segments resistant to AluI, DdeI, HinfI and HaeIII restriction endonucleases and identification of the C-banded heterochromatin presented herein have been used to arrange pikeperch chromosomes into the karyotype. After Primed in situ labeling (PRINS) technique with primers enabling amplification of 5S rDNA sequences, hybridization spots observed on the short (p) arms of two the largest pikeperch submetacentric chromosomes (no. 2). Fluorescence in situ hybridization (FISH) with telomeric PNA (Peptide Nucleic Acid) probe enabled recognition of the conservative telomeric DNA sequences on the pikeperch chromosomes. No interstitial signals were observed. The specimens studied did not show any morphologically differentiated sex chromosomes.