Worm Breeder's Gazette 11(4): 48
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
We have previously reported isolation of several C. elegans 'homeobox' clones from an EMBL4 genomic library probed with a unique oligonucleotide probe to the 'recognition helix' of Antp class homeodomain (Hawkins and McGhee, WBG 10(2)). One of these, ceh-10, has been partially characterized. A 0.9 kb genomic fragment of the lambda clone was sequenced and found indeed to contain a homeobox. Based on worm consensus sequences for donor and acceptor splice sites, a relatively large intron (367 bp), is predicted to fall between amino acids 46 and 47 of the deduced amino acid sequence. The sequence is most similar to that of the paired gene of Drosophila (60% identity at the a.a. Ievel; 70% if conservative changes are allowed) : [See Figure 1] Genes in the 'paired-class' share homology over an 'extended- homeobox', a gly-ser rich region, and a 'paired-box'. ceh-10 has good homology to prd in the extended homeobox and also has 75% gly/ser in the 20 a.a. 5' of this region but we have not yet found a paired-box. The ceh-10 gene maps to left C of chromosome III (mapping and cosmids kindly provided by Alan Coulson and John Sulston). A northern blot of embryonic polyA+ RNA shows a 1.25 kb message along with a minor band of 1.85 kb. These bands are much weaker in later stages suggesting that ceh-10 might be a developmentally interesting gene. We are now continuing the characterization of this homeobox gene. We have not yet found a ceh-10 gene in several cDNA libraries so we are now reconstructing a cDNA by PCR.