Figure 1.

Mutagenesis of the D-p38a locus. (A) Boxes indicate gene structure; shaded boxes indicate coding regions. Triangles indicate P-element insertion sites. EP(3)3637 was mobilized and the local hop EP(3)3637-2 recovered. Next, both P-elements were simultaneously excised, resulting in complete deletion of D-p38a. The black box indicates the size and position of the deletion, as determined by genomic DNA sequencing. Neither neighbouring gene was disrupted. (B) RT–PCR analysis confirms that D-p38a¹ is null for the locus. No D-p38a transcript is detected in mutants. Actin (control) levels are unchanged.