Genetic verification of induced gynogenesis and microsatellite-centromere mapping in the barfin flounder, Verasper moseri

Primer sets were newly developed for 34 polymorphic microsatellite loci in the barfin flounder Verasper moseri. Mendelian inheritance was confirmed by examining the genotypic segregation in two normal diploid full-sib families. All the 34 loci showed genotypic segregation according to the Mendelian manner of inheritance; in some cases, null alleles were assumed. The genotypes at 27 loci were also examined in four meiotic gynogenetic diploid lines produced by fertilizing eggs with UV-irradiated sperm, followed by inhibition of the second meiotic division by cold shock. The absence of paternal alleles verified the success of gynogenetic development in all four meiotic gynogenetic diploid lines; the proportion of heterozygous progeny of a heterozygous mother, i.e., the frequency of second division segregation (y), was used to estimate the map distance of each microsatellite locus in relation to the centromere. Marker-centromere distances were estimated to be in the range of 0 to approximately 50 centiMorgan (cM) under the assumption of complete interference. Using eight diagnostic loci located at the telomeric region of the chromosome, complete homozygosity was confirmed in 1 mitotic gynogenetic diploid line that was produced by suppressing the first cleavage via hydrostatic pressure shock.