The Polyclonal Structure of Unisexual Prussian Carp (Carassius gibelio (Bloch, 1782)) Settlements in Northern Ukraine: Comparison Analysis of Allozyme Markers and Chromosome Numbers

Abstract

An allozyme analysis of five sets of polymorphic loci of the gynogenetic Prussian carp C. gibelio from Northern Ukraine made it possible to identify within this species 29 genetic forms of clonal and recombinant nature, which can be divided into two categories. The first one is represented by the clonal C. gibelio-1 biotype with the modal number of 156 chromosomes and several unique alleles, which distinctly differentiate this biotype from the diploid goldfish C. auratus. The second category is represented by the group of 28 biotypes designated as C. gibelio-2 of a clonal and recombinant nature. Specimens of this group have no allozymes that distinguish them from C. auratus. Within this group, 158 and 160 modal chromosome groups were discovered; each one has special genotypic combination for locus Aat-1. Apparently, the series of biotypes, which are differentiated by the modal chromosome number, emerged independently as a result of hybridization of different pairs of parental species way back in Eastern Asia. At the same time, the emergence of recombinant individuals with unique combinations of genotypes of five protein loci and their own chromosome number within the C. gibelio-2 clone is a secondary event related to the implementation of the inheritance mechanism, which combines cloning and Mendelian inheritance. There are reasons to believe that this mechanism is implemented in pseudogamous crosses of genetically close C. gibelio-2 females with C. auratus males, while the cloning takes place in crosses of C. gibelio-2 females with more distant C. carassius males.