Unisexual and bisexual types of ginbuna, Carassius auratus langsdorfii in Aichi Prefecture

Article信州大学理学部紀要 19(1): 1-7(1984)departmental bulletin pape

Studies on the Gametogenesis in Polyploid Ginbuna Carassius auratus langsdorfii

The structural changes of the chromosomes during meiosis of gynogenetic triploid female ginbuna Carassius auratus langsdorfii, and naturally produced or sex-reversed male ginbuna were studied cytologically. In triploid female ginbuna, at zygotene stage two homologue-like chromosomes out of three were sometimes adjacent each other in the neighbourhood. At pachytene stage almost all of the chromosomes were univalents, and at diplotene stage almost all of lampbrush chromosomes were also univalents. From these results it seems probable that the two homologue-like chromosomes undergo synapsis at zygotene stage, but they might be separated to univalents on and after pachytene stage. Thereafter, each univalent chromosome might be split to two chromatids and result in separation of one chromatids to one direction and the other to the opposite one. In this way, the egg may maintain the maternal chromosome number and karyotype throughout the oogenesis. On the other hand, in some specimens at diplotene stage at most two to three bivalent lampbrush chromosomes, connected with one chiasma, were observed. These facts seem to explain the hypervariabilities among the gynogenetic triploid ginbuna. On the other hand, male individuals were almost similar to the processes in meiosis, though in some chromosomes it observed a few bivalents and rod-shaped bi-, tri-, and multivalent chromosomes at metaphase.Article信州大学理学部紀要 19(1): 37-52(1984)departmental bulletin pape

Analyses of Histocompability and Isozyme Variations in Triploid Fish, Carassius auratus langsdorfii

Clonal diversity of triploid gynogenetic fish, Carassius auratus langsdorfii, was examined by tissue grafts and electrophoreses of several enzymes and muscle protein. The hypervariabilities of histocompatibility clones and electromorph clones were observed in wild-caught specimens. The ratio of DNA value of each specimen to control diploid fish varied from 1.38 to 2.01. Unidirectional histocompatibility and protein variations in histocompatibility clones were the characteristics of this gynogenetic fish. These facts seem to indicate the divergence of a clone. Tissue-incompatibility was observed betweeen F脀 progeny of triploid ginbuna × Shubunkin. Some of offspring expressed the male-dependent transparent-scaled character. This indicates the fact that fusions of female and male pronuclei must have occured. In the other strain, random reductions of DNA values were observed. The divergence of a clone must have been caused by the gene addition or loss.Article信州大学理学部紀要 19(1): 9-25(1984)departmental bulletin pape