Xenogeneic Transfer of Adult Quail (Coturnix coturnix) Spermatogonial Stem Cells to Embryonic Chicken (Gallus gallus) Hosts: A Model for Avian Conservation1

Abstract

As advanced reproductive technologies have become routine for domesticated species, they have begun to be applied in the field of endangered species conservation. For avian conservation, the most promising technology is the transfer of germ stem cells of exotic species to domestic hosts for the production of gametes. In this study, adult quail (model for exotic species) spermatogonial stem cells were xenogeneically transferred to stages 14-17 chicken host embryos. Fluorescent cellular dyes, quail-specific antibodies, and quail-specific quantitative PCR confirmed donor cell migration to and colonization of the host gonadal ridge. Donor-derived cells were observed by fluorescent microscopy in the caudal area as early as 2 h after injection, in the gonadal ridge at 4 h after injection, as well as in the gonads of stages 35-38 host embryos. Four of eight donor-derived cell flow cytometry-positive host gonads were confirmed by quantitative PCR using quail-specific primers. There was no statistically significant effect of host stage of injection, host gonad isolation stage, or host sex on the number of hosts positive for donor cells or the percent of donor-derived cells per positive gonad. Donor-derived cells isolated from stages 35-38 host gonads costained with the germ stem cell marker SSEA-1, indicating that the donor-derived cells have maintained stem cell-ness. This is the first study to suggest that it is feasible to rescue adult germ stem cells of deceased birds to prolong the reproductive lifespan of critically endangered species or genetically valuable individuals by transferring them to an embryonic chicken host.

Spermatogonial stem cells: Current biotechnological advances in reproduction and regenerative medicine

“…Endangered species could also be benefited with such technologies. For instance, SSCs from the wild species to be preserved could be transferred to a phylogenetically related domestic animal embryo and this way become incorporated into the germline to eventually produce exotic sperm [99,100] , this way saving the endangered germplasm.…”

Transfer and Detection of Freshly Isolated or Cultured Chicken (Gallus gallus) and Exotic Species' Embryonic Gonadal Germ Stem Cells in Host Embryos

“…4A). The total number of cells in a pair of stage 36 embryo testes averaged 2.04 × 10 6 ± 2.2 × 10 5 and 2.00 × 10 6 ± 1.9 × 10 5 for the left ovary (Roe et al, 2013). This yielded a range of approximately 800 to 7600 and 800 to 3000 colonized donor-derived cells in hosts injected with fresh or 3d-cultured cells, respectively.…”

“…In addition, it is likely that some cellular reprogramming of donor cells occurs in the host embryo, as seen following transfer of adult testicular cells to embryonic host gonads (Minematsu et al, 2004; Jung et al, 2010; Roe et al, 2013). However, if reprogramming does not occur within the time the gonadal ridge migration signal is available, donor-derived cells may be unable to migrate and colonize, explaining the lack of larger numbers of donor-derived cells.…”

“…Fresh or cultured cells were injected as previously described (Naito et al, 1994b; Ono et al, 1996; Roe et al, 2013). A standard belt sander was used to make a 1.5 cm 2 opening in the host embryo shell, and 10,000 chicken or exotic donor gonadal cells suspended in 2–10 μL M199 medium (Mediatech, Inc.) were injected into the vitelline vein of unsexed chicken embryos at stages 14–17.…”

Establishment of a pheasant (Phasianus colchicus) spermatogonial stem cell line for the production of interspecies germ line chimeras

“…Germ cell techniques have been used for recent restoration efforts [6]. Studies of restoration in mammals are underway, but progress is slowed by long generation intervals.…”