title: Acquisition of the heat-shock response and thermotolerance during early development of Xenopus laevis.
abstract: The ability to synthesize a 68,000- to 70,000-Da protein (hsp) in heat-shocked early Xenopus laevis embryos is dependent on the stage of development. Whereas late blastula and later stage embryos synthesize hsp68-70 after heat shock, cleavage stages are incompetent with respect to hsp synthesis. In vitro translation experiments and RNA blot analyses demonstrate that enhanced synthesis of hsp68-70 is associated with an accumulation of hsp68-70 mRNA. Examination of the effect of heat shock on preexisting actin mRNA reveals that heat shock promotes a reduction in the levels of actin mRNA in cleavage embryos but has no discernible effect on actin mRNA levels in neurula embryos. Finally, the acquisition of the heat-shock response (i.e., synthesis of hsp68-70 and accumulation of hsp70 mRNA) during early Xenopus development is correlated with the acquisition of thermotolerance.
mesh_terms: D000367:Age Factors; D000818:Animals; D005786:Gene Expression Regulation; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D006358:Hot Temperature; D012333:RNA, Messenger / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D006360:Heat-Shock Proteins; D012333:RNA, Messenger