Differential regulation of closely related members of the hsp16 gene family in Caenorhabditis elegans

DNA. 1989 Sep;8(7):481-90. doi: 10.1089/dna.1.1989.8.481.


The heat-inducible genes encoding 16-kD heat shock polypeptides in Caenorhabditis elegans are found at two separate loci, one containing the 16-1 and 16-48 genes (locus A), and the other, the 16-2 and 16-41 genes (locus B). Despite the highly conserved structures of these genes and their promoters, the B locus produces up to sevenfold more mRNA during heat induction than does the A locus. Since there are two copies of the 16-1 and 16-48 genes at the A locus, the discrepancy in mRNA production is actually as high as 14:1 on a per gene basis. Measurements of the rate of hsp16 mRNA decay during recovery from a heat shock suggest that this difference is not caused by differential mRNA stability; furthermore, nuclear runon experiments yield rates of transcription for the 16-1/48 locus that are approximately threefold higher than those from the 16-2/41 locus. The higher levels of mRNA from the 16-2/41 locus, particularly at longer induction times, seem to be due to a marked difference in the temporal pattern of mRNA production from the two loci. While both loci are transiently activated by a heat shock, the 16-1 and 16-48 genes of the A locus are down-regulated to a lower transcription rate sooner than the genes from the B locus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis / embryology
  • Caenorhabditis / genetics*
  • Genes*
  • Genes, Regulator*
  • Heat-Shock Proteins / genetics*
  • Hot Temperature
  • Kinetics
  • Multigene Family*
  • RNA / genetics
  • RNA / isolation & purification
  • Restriction Mapping
  • Transcription, Genetic*


  • Heat-Shock Proteins
  • RNA