Fig. 5. Fusomal membranes are absent in hts¹ and present in bam⁸⁶ mutants. (A,A') hts¹-mutant germaria that do not contain a cytoskeletal fusome (Lin et al., 1994) do not show any concentration of Rtnl1-GFP (green in A and as a single channel in A') in cysts in the germarium (cysts are labeled by Orb-staining in red in A). (B) Control germarium with the usual concentration of Rtnl1-GFP (green) on the fusome and Orb concentration into the oocyte (red). (C-C") In bam⁸⁶-mutant germaria, which only contain spectrosomes and dump-bell shaped fusomes (McKearin and Ohlstein, 1995) marked by Hts (red in C and as a single channel in C"), Rtnl1-GFP associates with these fusomes (green in C and as a single channel in C'). Inset in C' shows Rtnl1-GFP in a wild-type germarium scanned at identical intensity to C'. The amount of Rnl1-GFP appears reduced. Bars, 10 µm.