MITOCHONDRIAL-DNA VARIATION IN 2 SAMPLES OF NORTHERN PIKE, ESOX-LUCIUS L

The mitochondrial genotype of northern pike, Esox lucius L., was chara cterized by restriction analysis performed over the entire mtDNA molec ule (33 fish) and over a approximate to 1.4-kb PCR-amplified segment o f a mitochondrial non-coding control region (six fish). Out of eight r estriction endonucleases used in the present study of the entire mitoc hondrial genome, the Nco I and Pst I enzymes produced variant fragment patterns which allowed identification of three mitochondrial genotype s, Low mtDNA diversity was shown by estimates of pairwise nucleotide s ubstitution values (d; mean +/- SE = 0.49 +/- 0.43%), haplotype divers ity (h = 0.16) and the nucleotide diversity index (pi = 0.06%). The pr esent authors developed a PCR protocol for mitochondrial DNA non-codin g control region to search for more variation. Whereas the PCR assays revealed distinct length variation in this mtDNA segment, restriction analysis performed with three additional restriction enzymes showed no variability which could be attributed to a gain or loss of a particul ar restriction site, Although the mtDNA analysis proved ineffective in genetic discrimination between the two northern pike samples studied, fish with rare mtDNA genotypes could be used for conducting experimen tal genome engineering or stocking studies with this species.