POLYMORPHISM OF THE GENE FOR HEAT-SHOCK-P ROTEIN HSP70 IN RAT STRAINSWITH NORMAL AND HYPERTENSIVE STATUS

RFLP in the hsp70 gene encoding a major heat shock protein was analyze d in rat strains with high and normal arterial blood pressure. Dimorph ism in the sets of DNA fragments was revealed after hybridization of t he hsp gene leader sequence with rat DNA digested with BamHI restricti on endonuclease. Type I RFLP was represented by the fragments of 12 20 0, 6500, 41 000 and 1600 bp in size. Type II RFLP corresponded to the set that included the fragments of 12 200, 6500, 2900, 1600, and 1200 bp in size. Interstrain polymorphism was demonstrated for the fragment s of 4100, 2900 and 1200 bp. Furthermore, analysis of different rat st rains showed that the 2900- and 1200-bp fragments were linked and form ed by cleavage of the 4100-bp fragment with restriction endonuclease. This polymorphism was probably caused by the point A --> T mutation oc curring in the BamHI recognition site located in the leader sequence o f the hsp70 gene at a distance of +35 bp from the coding sequence. Exa mination of interstrain RFLP in the hsp70 gene indicated that the pres ence of 2900-bp fragment was not associated with hypertensive status i n all experimental models of inherited arterial hypertension. This con firmins the assumption on genetic heterogeneity of this common disease .