We have isolated genomic clones representing six distinct members of the Caenorhabditis elegans 70-kDa heat-shock protein gene (
hsp70) family. Each member exists as a single copy element in the C. elegans genome. Transcripts of four of the
hsp70 genes have been detected by Northern-blot analysis. One member,
hsp70C, appears to be a heat- shock-cognate
hsp70 gene (
hsc70) since its transcription is developmentally regulated and is not increased in response to heat shock. Transcripts of another gene,
hsp70A, are abundant in control worms and are also increased (two- to six-fold) upon heat shock. Nucleotide sequencing of genomic and cDNA clones of
hsp70A reveals that it is highly homologous to Drosophila and yeast heat-shock- inducible and heat-shock-cognate
hsp70 genes. Three DNA elements homologous to the heat-shock promoter, 5'-C--GAA--TTC--G-3' are located upstream from the Hsp70A-coding region. We find that
hsp70A contains three introns, one of which is in a similar position with an intron in the Drosophila
hsc1 and
hsc2 genes. Finally, utilizing strain-specific restriction fragment length differences, we have mapped the chromosomal position of
hsp70A to the far right of chromosome IV.