New horizons for in vitro spermatogenesis? An update on novel three-dimensional culture systems as tools for meiotic and post-meiotic differentiation of testicular germ cells.
Culture and differentiation of male germ cells has been performed for various purposes in the past. To date, none of the studies aimed at in vitro spermatogenesis has resulted in a sufficient number of mature gametes. Numerous studies have revealed worthy pieces of information, building up a body of information on conditions that are required to maintain and mature male germ cells in vitro. In this review, we report on previously published and unpublished experiments addressing murine germ cell differentiation in three-dimensional (3D) in vitro culture systems. In a systematic set of experiments, we examined the influence of two different matrices (soft agar and methylcellulose) as well as the need for gonadotrophin support. For the first time, we demonstrate that pre-meiotic male germ cells [revealed by the absence of meiotic marker expression (e.g. Boule)] obtained from immature mice pass through meiosis in vitro. After several weeks of culture, we obtained morphologically normal spermatozoa embedded in the matrix substance. Complete maturation relied on support from somatic testicular cells and the presence of gonadotrophins but appeared independent from the matrix in a 3D culture environment. Further research efforts are required to reveal the applicability of this culture technique for human germ cells and the functionality of the spermatozoa for generating offspring.
Stukenborg
Jan-Bernd
JB
Institute of Reproductive and Regenerative Biology of the Centre of Reproductive Medicine and Andrology, University Münster, Domagkstrasse 11 48129, Münster, Germany.
Schlatt
Stefan
S
Simoni
Manuela
M
Yeung
Ching-Hei
CH
Elhija
Mahmoud Abu
MA
Luetjens
Craig Marc
CM
Huleihel
Mahmoud
M
Wistuba
Joachim
J
D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation; D006801:Humans; D008297:Male; D008540:Meiosis / Q000502:physiology; D051379:Mice; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology; D013737:Testis / Q000166:cytology*