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Fig. 2. Gene structure and expression. (A) achi and vis are
tandem duplications. The intron/exon structure is shown together with the
alternative splice products determined from completely sequencing the
following cDNAs: achi-class 1 LD25085,GM01582; achi-class 2 LP02076; vis-class
1 SD08875, SD01238. vis-class 2 intron/exon structure was determined by
sequencing a subclone of the ORF RT-PCR shown in D. Translation is initiated
in exon3 (arrow) and terminates in exon10 (asterisk). (B) RT-PCR analysis with
primers (f1 and r3) common to both achi and vis indicates
expression throughout development. A similar result was obtained with primers
specific for achi. The RP49 control gave approximately equal levels
with RNAs from all the different developmental time points. (C) Sex-specific
splice differences of achi/vis. Class 2 products predominate
in testes (lane 1) whilst class 1 products (lane 2) predominate in ovaries
(primers: f3 and r2). Similar results are seen comparing male and female whole
fly RNA (not shown). (D) Class 2 transcripts are testes specific. Lane 1:
testes; lane 2: male gonadectomised carcass and lane 3: adult females
(achi/vis ORF primers).