Recent advances of in vitro culture systems for spermatogonial stem cells in mammals

Abstract

BackgroundSpermatogonial stem cells (SSCs) in the mammalian testis are unipotent stem cells for spermatozoa. They show unique cell characteristics as stem cells and germ cells after being isolated from the testis and cultured in vitro. This review introduces recent progress in the development of culture systems for the establishment of SSC lines in mammalian species, including humans.MethodsBased on the published reports, the isolation and purification of SSCs, identification and characteristics of SSCs, and culture system for mice, humans, and domestic animals have been summarized.ResultsIn mice, cell lines from SSCs are established and can be reprogrammed to show pluripotent stem cell potency that is similar to embryonic stem cells. However, it is difficult to establish cell lines for animals other than mice because of the dearth of understanding about species‐specific requirements for growth factors and mechanisms supporting the self‐renewal of cultured SSCs. Among the factors that are associated with the development of culture systems, the enrichment of SSCs that are isolated from the testis and the combination of growth factors are essential.ConclusionProviding an example of SSC culture in cattle, a rational consideration was made about how it can be possible to establish cell lines from neonatal and immature testes.

Gametes from stem cells: Status and applications in animal reproduction

“…Extended and efficient proliferation of SSC in culture has been achieved in mouse and human (Kanatsu‐Shinohara et al, ; Sadri‐Ardekani et al, ). In most livestock species, only short‐term culture has been reported (reviewed by Sahare, Suyatno, & Imai, ), with better results in cattle (Oatley, Kaucher, Yang, Waqas, & Oatley, ) and pigs (Zhang et al, ).…”

PAX7 promotes CD49f‐positive dairy goat spermatogonial stem cells' self‐renewal

“…The processes in spermatogenesis last 35 days in mice (Oakberg, 1971), 74 days in humans (Y. J. A. Clermont, 2009), 63 days in cattle (Sahare, Suyatno, & Imai, 2018), and 40–60 days in goats (Cardoso & Queiroz, 1988; Franca, Becker‐Silva, & Chiarini‐Garcia, 1999). The existing self‐renewal models of SSCs in mice were Asingle (As), Apair (Apr), and Aalign (Aal) spermatogonia cells that act as stem cells during spermatogenesis (Phillips et al, 2010; Sahare et al, 2018).…”

“…A. Clermont, 2009), 63 days in cattle (Sahare, Suyatno, & Imai, 2018), and 40–60 days in goats (Cardoso & Queiroz, 1988; Franca, Becker‐Silva, & Chiarini‐Garcia, 1999). The existing self‐renewal models of SSCs in mice were Asingle (As), Apair (Apr), and Aalign (Aal) spermatogonia cells that act as stem cells during spermatogenesis (Phillips et al, 2010; Sahare et al, 2018). In humans, the spermatogonial renewal model postulates that the Adark and Apale spermatogonia cells are similar to Apr and Aal in rodents (Y. Clermont, 1966; Sahare et al, 2018).…”

“…The existing self‐renewal models of SSCs in mice were Asingle (As), Apair (Apr), and Aalign (Aal) spermatogonia cells that act as stem cells during spermatogenesis (Phillips et al, 2010; Sahare et al, 2018). In humans, the spermatogonial renewal model postulates that the Adark and Apale spermatogonia cells are similar to Apr and Aal in rodents (Y. Clermont, 1966; Sahare et al, 2018). It is still fuzzy in goat.…”

“…In humans, the spermatogonial renewal model postulates that the Adark and Apale spermatogonia cells are similar to Apr and Aal in rodents (Y. Clermont, 1966;Sahare et al, 2018). It is still fuzzy in goat.…”