Genetic and molecular analysis in the 70CD region of the third chromosome of Drosophila melanogaster

A collection of lethal and semi-lethal P-element insertions in the 70CD reg ion of chromosome 3 of Drosophila melanogaster was used to investigate gene s and gene arrangements by a combination of genetic, cytological, functiona l and molecular methods. The 12 lethal insertions studied fall into seven c omplementation groups of six genes. Lethal phases, expression patterns and other phenotypic aspects of these genes were determined. The genes and addi tional available sequences were placed on cloned genomic DNA fragments and arranged in an EcoRI map of 150 kb that covers approximately the bands 70C7 -8 to 70D1. Determination of deficiency breakpoints links the genetic, phys ical and molecular data. The sequences adjacent to seven independent P-elem ent insertions were established after plasmid rescue or polymerase chain re action. Similarity searches allowed the assignment of the P-element inserti ons to known mutations, expressed sequence tags, sequence tagged sites, or homologous genes of other species. Among these were identified a putative t ransacylase, a putative cell cycle gene, and the gene responsible for the d ominant Polycomb-suppressor phenotype of devenii. The genomic sequence of t he l(3)70Ca/b gene reveals a novel heat shock protein (hsc70Cb). l(3) 70Da was identified as a member of the CDC48/PEX1 ATPase family and its coding s equence was determined. (C) 2000 Elsevier Science B.V. All rights reserved.