The use of artificial gynogenesis in studies on the immune system of carp (Cyprinus carpio L.).

Gynogenetic carp were obtained by using gamma-irradiated sperm for fertilization followed by a cold shock. The gynogenetic fish and normal siblings of the same parents were analysed for 3 genetic markers: scale pattern, transferrin (Tf) and allograft rejection. Gynogenetic offspring showed only the maternal scale pattern (scattered). In the majority of the gynogenetic fish a heterozygous Tf pattern identical to the mother was observed. Animals homozygous for Tf were rare in this group. A typical paternal Tf band was only seen in normal siblings. An exchange of skin grafts between normal animals was always followed by rejection (median survival time, 12 days at 23 OC). However, the rejection was delayed in the gynogenetic group (MST, 19,6 days). There were even signs of acceptance in some animals. This approach can be used for the identification of 2nd and 3rd generation gynogenetic fish, which are homozygous for certain MHC haplotypes.