Figure 3.

DNA sequences of N^nd-p and its hybrid-dysgenesis-induced revertants. (A) Nucleotide sequence of the P-element insertion site in N^nd-p. The first 900 bp of the first N exon are shown. The protein-coding region is in uppercase letters. The 8-bp site duplication created by the insertion of the P element is double underlined. The positions of the two primers used to amplify the revertant fragments for DNA sequencing are underlined. (B) Partial sequence of the two revertants of N^nd-p. A partial sequence of the wild-type sequence of N reported in FlyBase (CG3936, FBgn0004647) is given as a reference. It contains a seven-base-pair sequence that is not found in N^nd-p or the two revertants and a C/A polymorphism. These sequences are unde-lined. The eight-base-pair sequence that was duplicated during the insertion of the P element in N^nd-p is double underlined in all of the sequences. The first revertant is a precise excision of the P element. The second revertant is an imprecise excision. A forty-eight base-pair sequence derived from the P element is located between the site duplications in this revertant.