The Drosophila homolog of the immunoglobulin recombination signal-binding protein regulates peripheral nervous system development

Abstract The J κ RBP binds to the immunoglobulin recombination signal sequence flanking the κ-type J segment. We previously Isolated the highly conserved homolog of the J κ RBP gene from D. melanogaster, which is not thought to have immunoglobulin molecules. Using many deficiency mutants and in situ hybridization, we mapped the Drosophila J κ RBP gene in a region containing two recessive lethal mutations, i.e., br26 and br7 , which shows the dominant Suppressor of Hairless (Su(H) ) phenotype in heterozygotes. All six Su(H) alleles analyzed at the DNA level contained mutations in the Drosophila J κ RBP gene. Since the Su(H) mutation affects peripheral nervous system development, the Drosophila J κ RBP gene product is involved in gene regulation of peripheral nervous system development. The results also imply that the immunoglobulin recombination signal sequence and the target sequence of the Drosophila J κ RBP protein might have a common evolutionary origin.