Figure 3.

Physical map of the mei-W68 region. (A) The restriction map came from two sources: our own restriction mapping of DS00571, and the Genome Project sequencing of the overlapping P1 DS07982. The molecular structures of three mei-W68 deletion mutants are shown. The brackets above the genetic map are to indicate that the LL4, LL5, and LD3 chromosomes are deletions with one endpoint at the original P{lacW}l(2)k06323 insertion site. (B) Depiction of the mei-W68 transcript showing the intron/exon structure and the location of the insertions in mei-W68¹ and mei-W68^k05603. To show that the mei-W68¹ insertion was not in the first or second introns, we probed HindIII and XhoI digests with labeled EcoRI fragment pWE31 (B). The appearance of the larger insertion band in the HindIII digest and the wild-type bands in the XhoI digest (data not shown) showed that the insertion site was between the first and second introns. The position of the k05603 insertion was determined from sequence obtained by the genome project off the 5′ end of the P element (Berkeley Drosphila Genome Project).