ABSTRACT
The development of methods for the in vitro study of mammalian spermatogenesis faces problems due to tissue specificities that are difficult to attain under culture conditions. These problems arise because spermatogenesis depends strongly on the compartmentalization of cellular associations, for example topographic arrangements that determine spatial and temporal relationships between gene expression and specific signal molecules. Even if stable somatic cell populations such as peritubular cells, Leydig cells and Sertoli cells, and stem/progenitor germ cells such as mitotic dividing spermatogonia, can be maintained, this is very difficult to achieve with differentiated germ cells such as meiosis-driven spermatocytes and spermatids. Hence, at present, the major goal of somatic cell-germ cell coculture systems is to establish a minimum of conditions that can artificially keep alive a more or less functional epithelium for a reasonable period of time (2-3 weeks).
