Fig. 8. Posterior Vas localization requires vls. Wild type has two copies of vas-eGFP. vls^null vls⁺, vls^PG65 and vls^null have one copy of vas-eGFP. Fixed ovaries are shown here. Live ovaries show a similar pattern although nuage signal is generally stronger than in fixed ovaries. (A-D) Stage 1-5 egg chambers, (A'-D') stage 10 egg chambers. (A,A') Wild-type localization of Vas-eGFP to nuage and to the posterior of the oocyte is observed in Sp/SM1 background. Nuage localization in vls mutants appears normal initially (C,D) and slightly reduced in stage 10 egg chambers (C',D'); however, we did not observe this reduction in live ovaries (data not shown). Posterior localization of Vas-eGFP in the oocyte is undetectable in vls^null mutants (D') and dramatically reduced in vls^PG65 hemizygotes (C'). This defect is rescued by the introduction of the vls⁺ transgene (B'). The levels of posterior Vas-eGFP appear reduced in vls^null vls⁺ oocytes, most probably because of the lower copy number of vas-eGFP. (E-H') Vas-eGFP is not detected at the posterior of young embryos from vls mutant mothers. (E-H) 0- to 1-hour-old embryos, (E'-H') 2- to 3-hour-old embryos. Vas-eGFP accumulates at the posterior of embryos (E,F) and then inside newly formed pole cells (E',F') in wild-type and vls^null vls⁺ background, but not in embryos from vls^PG65 hemizygous (G,G') and vls^null mutant (H,H') mothers.