Title Germ cell transplantation in fish: A novel approach for conservation of genetic resources
Authers Goro YOSHIZAKI
Keywords spermatogonia, primordial germ cell, vasa, endangered species, surrogate broodstock
Citation Bull. Fish. Res. Agen. No.26, 99-105, 2008
To date, we do not have any cryopreservation method for fish eggs and embryos. Therefore, there is no available system to preserve fish genetic resources other than raising live individuals in captivity. To overcome this obstacle, we recently established a system to cryopreserve trout spermatogonia using slow-freezing method. In order to convert isolated spermatogonia into functional gametes, we established a novel spermatogonial transplantation method. Spermatogonia from male trout were transplanted into the peritoneal cavity of newly hatched sterile triploid salmon. The transplanted trout spermatogonia migrated towards the recipient salmon genital ridges, and were subsequently incorporated into them. In male recipients, transplanted spermatogonia underwent spermatogenesis. Further, in female recipients, transplanted spermatogonia underwent oogenesis. At 2 years after transplantation, sterile salmon recipients only produced donor-derived trout sperm and eggs. By artificial insemination with the sperm and eggs obtained from the triploid salmon recipients, only the donor-derived trout offspring was successfully produced. Thus, the transplanted trout germ cells proliferated and matured normally in a xenogeneic microenvironment. Combined with cryopreservation of spermatogonia, the xeno-transplantation technique would make it possible to preserve fish genetic resources and to revive extinct species using closely related species as a surrogate when necessary.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull26/yoshi.pdf