Mitochondrial DNA variation in diploid and triploid forms of silver crucian carp Carassius auratus gibelio

Variation of two mtDNA fragments amplified in polymerase chain reaction was compared by the RFLP method in a population of the sympatric bisexual (diploid) and gynogenetic (triploid) forms of silver crucian carp. The mtDNA haplotypes of all individuals was shown to be divided into two phylogenetic groups differing by at least 2.5% of nucleotide substitutions in their sequences. All gynogenetic individuals have haplotypes of a single phylogroup, whereas haplotypes of diploid fish belonged to both mtDNA phylogroups. This testifies to a possibility of transformation of gynogenetic individuals into a bisexual form, whereas the reverse process is either extremely rare or impossible.