Inducible Primordial Germ Cell Removal without Altering Sexuality of Red Crucian Carp

Objective A primordial germ cell (PGC)-removed red crucian carp was obtained to investigate effects of the genetic alternation on the sexual development and reproduction of the fish.

Method A PGC-specific expression of nitroreductase (Ntr)-containing strain of red crucian carp line with PGC removed by a metronidazole (Mtz) immersion-targeted treatment at early development stage was continuously observed, sampled, and dissected for anatomical differentiations under a microscope.

Result A stable and heritable red crucian carp line carrying the specific PGC marker fluorescence was successfully secured. Since Mtz can be converted by Ntr into a cytotoxic metabolite, the induction in the fish did not affect the PGC migration nor the number of fluorescently labeled cells. Thus, the PGC-removed transgenic line showed no pathological changes in the gonads and continued to reproduce offsprings with a sex ratio similar to that of control.

Conclusion The removal of PGCs in red crucian carp at the embryonic stage exhibited no interference to the sexual development of the fish, and the sex differentiation of this fish may depends on the somatic cells of gonads.