Morphometric characteristics and reproductive capacity of nuclear transplants derived from embryonic cells of loach, Misgurnus anguillicaudatus

Abstract

Nuclear transplants of loach were produced by transplantating blastula cell nuclei into nonenucleated unfertilized eggs, using recipient eggs and donor cells distinguished by different polymorphic microsatellites. Of the total of 2,847 operated eggs, 143 hatched and 119 developed to the feeding larval stage. For 15 nuclear transplants (i.e., 11.1-year-old fish and 4.2-year-old fish) that survived up to the adulthood, DNA analysis and karyotype analysis were performed. Results showed that, of the 15 fish, 14 had only a nucleus derived from the donor; moreover, 12 were diploids, 1 was a triploid, 1 was a tetraploid, and 1 was a diploid-tetraploid mosaic with both donor and recipient nuclei. For the 12 fish with only a 2n donor nucleus, morphometric analysis was performed, and two female fish and two male fish were mated with normal fish. The fish with only a 2n donor nucleus were determined to be morphometrically identical to normal fish: they had normal gametogenesis and were able to reproduce. Currently, nuclear transplantation technology is beginning to be adopted in fisheries. Biological information on nuclear transplants obtained in this study can be used in the development of nuclear transplantation technology.