Fig. 2. Maelstrom is a spindle-class gene. (A) Distribution of synaptonemal complex component C(3)G (green) in a wild-type ovariole labeled with DAPI (blue) and for Adducin (red), which marks fusomes and cell membranes. C(3)G is normally acquired by germline chromosomes in region 1 of the germarium (top left) and is restricted to the oocyte nucleus by stage 1 (lower right). (B) The localization of C(3)G on chromosomes is unperturbed in most maelstrom null ovaries. (C) Magnified views of oocyte nuclei from wild-type and maelstrom oocytes. Top row (WT), wild type; bottom row (M), maelstrom (left to right): stage 1 C(3)G (green channel) and DNA (blue channel); stage 1 DNA channel; and stage 5/6 DNA. Wild-type (D) and maelstrom (E) stage 5/6 oocytes labeled with DAPI (green) and for nuclear lamin (red). Chromosomes within the wild-type oocyte nucleus (D) have condensed to form the karyosome. A maelstrom stage 5/6 oocyte (E), in which the karyosome never forms. (F) Distribution of BicD (green) in a wild-type stage 5/6 oocyte. Follicle cells are labeled with -Spectrin (red). BicD appears in a distinct gradient emanating from the posterior oocyte cortex. In maelstrom oocytes at this stage, BicD appears in a randomly localized focus (G) or unlocalized (not shown). Several RNAs, such as gurken, which localize to the posterior cortex of the wild-type stage 5/6 oocyte (H), are present at normal levels, but fail to localize in the maelstrom mutant (I) (oocytes indicated by broken blue lines). (J) Distribution of Gurken protein (green) in a wild-type stage 5/6 oocyte with follicle cells labeled for -Spectrin (red). Gurken is present at either low (K) or undetectable (not shown) levels in both maelstrom (K) and mei-W68¹; mael^M391/Df(3L)79E-F (L) oocytes. (M) Western blot of Vasa in wild-type (WT), mael^M391/Df(3L)79E-F(M) and spn-B¹⁵³/Df(3R)trxE12^* (B) backgrounds. In wild-type ovaries, Vasa runs as a 72.4 kDa singlet. In maelstrom, Vasa runs as a doublet, the slower migrating band of which has a larger apparent mass (74.4 kDa) than that of spn-B mutant. (MW markers are indicated on the right of the panel, the upper dot is at 83.6 kDa, and the lower dot is at 72 kDa). Nurse cell to the oocyte transport of oskar mRNA in maelstrom (O) ovarioles is comparable with wild-type (N). Scale bars: in L, 10 µm for A-D,F-L; in O, 50 µm for N,O.

Return to article