Deletions of two heat-activated loci in Drosophila melanogaster and their effects on heat-induced protein synthesis.

Deficiencies that delete two heat-induced puffs in Drosophila melanogaster have been isolated. Two deficiencies delete the puff arising from 87C1, and one deletes the two puffs at 87A and 87C1. Homozygotes for these deletions can be recognized by their abnormal, transparent malpighian tubules. The influence on heat-induced protein synthesis of deleting one or both of these puffs has been examined. Unexpectedly, deleting only the 87C1 puff has no apparent effect. Deleting both the 87A and 87C1 puffs eliminates synthesis of a 71,000 dalton protein. We map a coding locus for the 71,000 dalton heat-induced protein to 87A7-B3, a seven band region which also contains a heat-induced puff. The roles of the 87A and 87C1 puffs in coding for heat-induced proteins are discussed in the light of these results.