The autosomal genes
him-5 and
him-8 affect X-chromosome disjunction and recombination.
him-5 mutants also have detectable, but less severe, effects on autosomal disjunction. Each of the genes has been localized to specific chromosomal regions by mapping and transformation rescue experiments. Further molecular analysis will be described. For
him-8, two different but overlapping cDNAs have been identified, each of which has given a Him phenotype by RNAi. One transcript from the putative gene has a very long (200 nt) 5' UTR which appears to be highly conserved in C. briggsae. The 3' end of the gene has not yet been identified. For the
him-5 rescuing region, three different candidate genes were predicted by Genefinder or by the Intronerator. Despite extensive effort, we have been unable to verify that two of these predicted genes are transcribed, and
him-5 mutants do not have lesions in these candidate genes. The third gene is not only transcribed but also alternatively spliced. This is our best candidate for
him-5, and several different cDNAs have been isolated from this gene. RNAi is being attempted with these cDNAs. We hope to be able to report those results.