Figure 2.

Dispersed cell suspensions from MT-lacZ neonatal rat testes. (A) Unstained and unselected cell suspension. Pseudopod (arrowhead) and round (arrow) gonocytes can be recognized by their large size and distinct morphology. (B) Stained, unselected cell suspension. Pseudopod (arrowhead) and round (arrow) gonocytes express the lacZ transgene and stain blue in the presence of X-Gal. The majority of gonocytes (blue cells) in MT-lacZ neonatal rat testes can be categorized as pseudopod or round and these two phenotypes are equally represented in the gonocyte population (see Table 1). Higher magnification pictures of pseudopod (C) and round (D) gonocytes demonstrating large size and unique morphology. Distinct pseudopod extensions associated with a single gonocyte are indicated by arrowheads in C); note that because β-galactosidase activity is localized in the nucleus, pseudopod extensions do not stain blue. Homogeneous populations of pseudopod (E) and round (F) gonocytes were selected from unstained, live testis cell suspensions, placed in a second Petri dish, and stained with X-Gal to assess selection accuracy. [Bars = 200 μm (A and B) and 50 μm (C–F).]