Fig. 1. mael^M391 is a null allele. (A) Organization of the maelstrom gene. Exons are indicated by boxes in which coding regions are black and UTRs are white. The P [w+lacZ]11A4 insertion is indicated by a lavender arrow, and the region deleted () in mael^M391 is ochre. (B) Wild-type genomic DNA sequence at the junctions of the deletion. The P element is inserted between basepairs corresponding to nucleotides 123/124 of the mRNA. The DNA encoding nucleotides encoding 129-1266 of the mRNA is indicated by (dots). (C) The imprecise P-element excision in mael^M391 results in the deletion of 1319 basepairs of genomic DNA corresponding to nucleotides 124-1270 (including the initiation codon) of the mRNA. The residual P-element sequence is indicated by the purple background. (D) Maelstrom staining in a wild-type ovariole. Immunoreactive signal is predominant in cells throughout the germline. (E) Maelstrom or (F) Maelstrom (green) and Adducin (red) staining of a mael^M391/Df(3L)79E-F ovariole. Virtually all anti-Maelstrom immunoreactive signal is lost in the mutant. In the Western blot (G) probed with anti-Maelstrom antiserum, neither the full-length wild-type (left, at 50 kDa) nor potential truncated forms (not shown) of Maelstrom is detected in mael^M391/Df(3L)79E-F ovaries lane (right).