Caenorhabditis elegans has scores of homoeobox-containing genes
Abstract
HOMOEOBOX-containing genes control cell identities in par-ticular spatial domains, cell lineages, or cell types during the development of Drosophila1,2 and Caenorhabditis elegans3-5, and they probably control similar processes in vertebrates6-9. More than 80 genes with homoeoboxes that have sequence similarities ranging from 25 to 100% have been isolated by genetic means or by DNA hybridization to previously isolated genes10. We synthesized 500-2,000-fold degenerate oligonucleotides corre-sponding to a set of well-conserved eight amino acid sequences from the helix-3 region of the homoeodomain11. We screened C. elegans genomic libraries with these probes and identified 49 putative homoeobox-containing loci. DNA sequencing confirmed that eight out of ten selected loci had sequences corresponding to the conserved helix-3 region11 plus additional flanking sequence similarity. One of these genes contained a sequence corresponding to a complete pou-domain12 and another was closely related to the homoeobox-containing genes caudal/cdx-113,14. The putative homoeobox loci were mapped to the physical contig map of C. elegans15,16, allowing the identification of potentially correspond-ing genes from the correlated genetic map. We estimate that the number of homoeobox-containing genes in C. elegans is at least 60, constituting ~1% of the estimated total number of genes17.
- Publication:
-
Nature
- Pub Date:
- September 1989
- DOI:
- 10.1038/341239a0
- Bibcode:
- 1989Natur.341..239B