Colonization, proliferation, and survival of intraperitoneally transplanted yellowtail Seriola quinqueradiata spermatogonia in nibe croaker Nibea mitsukurii recipient

Recently, we developed an intraspecies spermatogonial transplantation technique in a pelagic egg spawning marine teleost, nibe croaker Nibea mitsukurii. Nibe croaker is an ideal candidate recipient for spermatogonial transplantation since it has a short generation time and small body size. In the present study, yellowtail Seriola quinqueradiata spermatogonia were transplanted into nibe croaker larvae, and the behavior of transplanted spermatogonia in recipient gonads was observed. Three weeks post-transplantation, yellowtail spermatogonia were incorporated into the gonads of 72 out of 88 recipients. An antiproliferating cell nuclear antigen was detected in incorporated yellowtail spermatogonia, suggesting that the xenogenic germ cells were proliferating in recipient gonads. Yellowtail vasa-positive spermatogonia survived for 11 months after transplantation in the gonads of recipient fish. Thus, we showed that the microenvironment in nibe croaker gonads can support the colonization, proliferation, and survival of germ cells derived from a different taxonomic family.