Fig. 2. Insertion of a springer retrotransposon is responsible for the da^lyh mutation. (A) A wild-type ovariole (upper) and a da^lyh mutant ovariole (lower) stained for Da protein. Arrows indicate the anterior end of each ovariole. Da protein is apparent in nuclei of wild-type somatic cells of the ovariole; no nuclear-localized protein is seen in da^lyh mutant ovarioles. (B) Graphical representation of the da genomic region. The da^lyh chromosome has a 7.5 kb springer element inserted within the single intron. Below the map are the extents of the Frag 5 DNA probe (Cronmiller et al., 1988), used for the northern blot shown in D, and the genomic fragment used in construction of the da.G32 reporter (Wodarz et al., 1995), used in the real-time RT-PCR analysis shown in Fig. 5. (C) Comparison of the conceptual translation products of the springer and gypsy retrotransposons. A complete springer nucleotide sequence was assembled from the ends of the da^lyh insertion and the Drosophila genome project sequences. Orientation of the springer is opposite of that in B. (D) Transcriptional analysis of da^lyh. Poly(A)⁺ RNA from wild-type and mutant da^lyh adults was probed with the da fragment 5 (B) to detect da RNA and the 3' adjacent fragment 6 (Cronmiller et al., 1988) to detect Mdh1 RNA as a loading control. Both da transcripts and the single Mdh1 transcript are indicated. RNA sizes are in kilobases.

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