Maintenance of adult mouse type A spermatogonia in vitro: influence of serum and growth factors and comparison with prepubertal spermatogonial cell culture.
The culture of spermatogonial cells under well-defined conditions would be an important method for elucidating the mechanisms involved in spermatogenesis and in establishing tissue regeneration in vivo. In this study, a serum-free culture system was established, with type A spermatogonia isolated from adult vitamin A-deficient mice. At days 1, 3 and 7 of culture, the viability and proliferation of cells were monitored. The viability of the cells decreased by day 7 to 10% of the cells present. Proliferation occurred mainly during day 1, when 1% of the germ cells was proliferating. Co-labelling for a germ cell marker (heat shock protein-90alpha, Hsp90alpha), and a marker used to detect dividing cells (bromodeoxyuridine, BrdU), showed that this proliferation was restricted to germ cells. In an attempt to improve these parameters, medium containing fetal calf serum (FCS) was used. Viability was not influenced by serum, but proliferation was markedly enhanced. However, after day 7 of incubation with FCS, co-immunolocalization for Hsp90alpha and BrdU showed a preferential proliferation of somatic cells. Comparison of cultures of adult cells with cultures of prepubertal germ cells, commonly used in studies of spermatogenesis, showed that prepubertal germ cells are twice as viable. In addition, a different proliferation profile was observed, with a peak at day 3. Here, a distinct proliferation of somatic cells was also noted. The results from the present study indicate that the origin of isolated germ cells partly determines culture outcome and that cultures of prepubertal germ cells may not be representative for adult spermatogenesis. Moreover, adding FCS to the culture medium invokes the risk of profound and undesirable effects on cell composition, also underlining the need for identification of germ cells during culture.
Creemers
L B
LB
Department of Endocrinology, Faculty of Biology, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands. l.b.creemers@bio.uu.nl
den Ouden
K
K
van Pelt
A M M
AM
de Rooij
D G
DG
D000818:Animals; D001973:Bromodeoxyuridine / Q000032:analysis; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division; D002470:Cell Survival; D016895:Culture Media, Serum-Free; D006133:Growth Substances; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012741:Sexual Maturation; D013093:Spermatogonia; D013997:Time Factors; D014802:Vitamin A Deficiency
D016895:Culture Media, Serum-Free; D006133:Growth Substances; D018841:HSP90 Heat-Shock Proteins; D001973:Bromodeoxyuridine