Fig. 1. SGPs individually ensheath germ cells during gonad formation. Anterior is leftwards. (A-E) UAS-mCD8-GFP expressed in the germ cells (nos-Gal4; A,B) or the mesoderm (24B-Gal4; C-E) of stage 13 (A,C), stage 15 (B,D) or stage 16 (E) embryos. (A,B) Anti-GFP labels the surface of germ cells, SGPs are labeled with anti-EYA. Note that the germ cells are round during gonad coalescence. (B, inset) Migrating germ cell (stage 11). (C,D) Somatic cell surfaces labeled with anti-GFP and SGP nuclei labeled with anti-EYA. Embryos are male, identified by the presence of EYA-positive msSGPs at the posterior of the gonad. Germ cells (e.g. asterisk) are surrounded by thin, SGP-derived cellular extensions in the uncoalesced (C) and coalesced (D) gonad. (E) Somatic cell surfaces labeled with anti-GFP and germ cells labeled with anti-Vasa. Closely apposed germ cells remain extensively ensheathed in late stages of embryogenesis. (F) Agametic stage 15 embryo (osk). SGPs labeled with anti-ZFH-1; anti-Neurotactin (NRT) labels the surface of many cell types, including the SGPs. Broken line indicates the boundary of the gonad. Arrows indicate SGP extensions around germ cells. Scale bar in A: 10 µm.