Successful transplantation of bovine testicular cells to heterologous recipients

Abstract

While heterologous germ cell transplantation was successful in pigs and goats, autologous transplantation alone has been reported to result in donor-derived spermatogenesis in cattle. The objective of this study was to investigate whether the transplantation of heterologous germ cells could result in colonization of recipient testes in cattle of different breeds. Testicular cells were isolated from 8 Bos taurus donor bull calves and then transferred into 15 Bos indicus-cross bull calves. All animals were pre-pubertal, donors were aged 5-7 months and recipients 5-11 months, and scrotal circumferences ranged from 15 to 22 cm. Single cell suspensions of donor testicular cells, prepared by enzymatic digestion, were labelled with fluorescent dyes PKH26 or CFDA-SE, before transfer into the rete testis of recipients under ultrasonographic guidance. To assess the longevity of colonization by donor cells, recipients were castrated 2-30 weeks after cell transfer. Donor cells were observed in 15/25 (60%) of the testes that received PKH26-labelled cells, whereas no CFDA-SE-positive cell was identified in any recipients. The maturity of the donors or recipients (measured by scrotal circumference) did not affect colonization potential. In freshly isolated tubules, clumps of PKH26-positive cells were observed, which indicated either cell division or extensive local colonization of specific areas of the tubules. In frozen sections, PKH26-positive cells were identified on the seminiferous tubule basement membrane, which indicated that these cells had successfully migrated from the tubule lumen and were likely to be spermatogonia. We conclude that PKH26 was more suitable for labelling donor testis cells and donor cells can be identified up to 6 months following transfer. These results indicate that allogeneic transplantation of testicular cells can occur between Bos taurus and Bos indicus cattle. Further studies will investigate functionality of transferred testicular cells.

Propagation of bovine spermatogonial stem cells in vitro

“…However, in bulls, colonization and full spermatogenesis has been achieved only after autologous transplantation of SSCs (Izadyar et al 2003b). After homologous and heterologous transplantations, full spermatogenesis has not been shown (Izadyar et al 2003b, Herrid et al 2006, probably because stem cells might not survive to an immunological reaction against them, so no or few daughter cells are formed.…”

The effect of combining vitamin E and C on the viability improvement of transfected ovine spermatogonial stem cells after cryopreservation and thawing

“…Thus, in farm animals, combining male germ cell transplantation with a large-scale culture of SSCs would provide a renewable source of stem cells for transplantation (3). This system has great potential since it provides proper alternatives to artificial insemination (AI) for the use of elite sires in an extensive production system in which AI is more impractical (4). Moreover, SSCs can be utilized in gene transfer to the next generation and this is proved to be more effective and time-saving than other approaches such as the use of embryonic stem cell or nuclear transfer technologies (5).…”

Spermatogonial stem cells from domestic animals: progress and prospects

“…As reported, SSCs from domestic species could colonize and proliferate in host mouse testes after transplantation, but could not give rise to entire spermatogenesis , Izadyar et al 2002, Oatley et al 2002, Kim et al 2006; Table 2), probably due to the phylogenetic disparity between donors and hosts. Later, allogeneic transplantation of SSCs was tested in boars, bulls, goats, sheep, and dogs (Honaramooz et al 2002a, Izadyar et al 2003, Herrid et al 2006, 2009b, Kim et al 2008, and the development of the donor germ cells was observed in those recipients of homogeneous species ( Fig. 2A and Table 2).…”