Genetic structure of ovoprotein loci in the process of creation of a dimorphic population of geese

Abstract

The work was carried out in the breeding plant DPPP “Rozdolne” of Kharkov region for breeding geese of Large Gray and Rhine breeds. As a result of direct and reverse crossings of birds of these breeds, geese of dimorphic population with double autosexuality were bred at the age of one day and at one age. A study of the genetic structure of polymorphic loci of egg white geese of the original parental forms, descendants of the first and third generations and the created dimorphic population. After starch gel electrophoresis, the fractional composition of ovoproteins was divided into the following intensely colored zones: ovoalbumin (OV), ovomucoid (OM), transferrin (TF), ovomacroglobulin (OMG). In the experimental bird, the OV, TF, and OMG loci were found to be monomorphic – all individuals had a homozygous AA phenotype, so the frequency of the *A allele in each of these loci was 1,000. Significant differences between the studied groups of geese were found at the locus of ovomucoid OM, which turned out to be strongly polymorphic and represented by a three-allele codominant system *A, *B, *C. The differences are primarily related to the nature of the distribution of phenotypes and the degree of coincidence of the actual and theoretically expected number. In all studied groups of birds, the basis of the population gene pool consisted mainly of carriers of the OM*A allele in the homo- or heterozygous state. In this case, less heterozygous individuals of AB were actually detected, and homozygous AA - more than theoretically expected. In the locus that determines the ovomucoid polymorphism, the frequency of the more common allele *A in geese of the studied groups was in the range of 0.531-0.750. It should be noted that significant differences in the frequency of alleles in this locus between the geese of the studied populations were not achieved. According to the level of heterozygosity, no probable difference was found between the studied groups of birds. The lowest rate of heterozygosity was found in Large Gray geese (7.19%), in the Rhine slightly more - 12.19%. In geese of the first generation, the level of heterozygosity occupies an intermediate position (11.56%) between the original parent breeds. In geese F₂-F₃ and dimorphic population, the level of heterozygosity increases to 13.75-15.00%.