Rapid sequence divergence in a heat shock locus of Drosophila

In situ hybridization of cRNA transcribed from cloned D. melanogaster heat shock sequences to D. hydei chromosomes has shown that the D. hydei locus 2--32 A corresponds to the D. melanogaster locus 87 A/C and the D. hydei locus 2--36 A to the D. melanogaster locus 95 D, while the D. hydei locus 4--81 B corresponds to the D. melanogaster locus 63 BC. No hybridization to D. hydei chromosomes was found with cRNA transcribed from a clone containing the alpha beta sequences encoded by the D. melanogaster locus 87 C. Neither D. melanogaster heat shock RNA nor D virilis heat shock RNA hybridized significantly to the D. hydei heat shock locus 2--48 B. Furthermore, D. hydei heat shock RNA did not hybridize to the cytological homologs of locus 2--48 B found in D. repleta or in D. virilis. D. hydei heat shock. RNA did hybridize to the cytological homologs of locus 2--48 B in D. neohydei and D. eohydei, both of which belong to the hydei subgroup.