Variability of response of early <i>Drosophila</i> embryos to heat shock

Abstract

Abstract Several embryonic stages (nuclear multiplication stage up to blastoderm) were incubated at 37°C. The 84,000 dalton heat‐shock protein was always present in the heat‐shocked embryos at all these stages. This protein was also found in nonheat‐shocked controls. Different amounts of two other heat‐shock proteins, the 70,000 and 68,000 daltons, were synthesized depending upon the embryonic stage. A massive synthesis of these two later proteins was observed in embryos which were able to recover from the heat‐shock.