EXTENSIVE REGIONS OF HOMOLOGY IN FRONT OF THE 2 HSP 70 HEAT-SHOCK VARIANT GENES IN DROSOPHILA-MELANOGASTER

[摘要] The major heat shock protein of 70,000 Mr [MW] in D. melanogaster is encoded by 2 variant gene types located, respectively, at the chromosomal sites 87A7 and 87C1. The DNA sequence of a complete hsp70 gene of the 87A7 type and of the adjacent regions from both variants is presented, extending to 1.2 .times. 103 bases upstream from the start of the messenger coding region. An untranslated region of 250 nucleotides at the 5'' end of the messenger coding sequences in both variants is found. Only 1 open reading frame allows coding of a 70,000 Mr protein within the 87A7 variant, as found for an 87C1 variant, 4.2% nucleotide divergence between these 2 variants with complete conservation of the reading frame. There is a conserved sequence of 355 nucleotides in front of each hsp70 gene, which is 85% homologous between the 2 variants. The presence of the same sequence element in .gamma., in front of the .alpha..beta. heat shock genes suggests that this element contains the regulatory signals for the coordinate expression of both the hsp70 and the .alpha..beta. heat shock genes. A very A + T-rich sequence of 150 base pairs is found, which is highly conserved (91.8%), 0.6 .times. 103 bases upstream from 2 hps70 gene variants.