Evolution of thermotolerance and the heat-shock response: evidence from inter/intraspecific comparison and interspecific hybridization in the virilis species group of Drosophila. I. Thermal phenotype.

摘要: Species in the virilis group of Drosophila (fruit flies), which overlap or replace one another along climatic gradients, exhibit corresponding differences basal thermotolerance, inducible thermotolerance and heat-shock response. The low-latitude species D. exceeds high-latitude lummei these measures temperature threshold for factor (HSF) activation ability to express hsp70 mRNA diverse proteins (e.g. Hsp70, Hsp83 small Hsps) after intense heat shock 40-41 degrees C). xeric novamexicana differs from mesic texana much same way many traits. By contrast, intraspecific variation traits is small. Because can readily be crossed yield partially fertile progeny, genetic analysis interspecific possible. Interspecific hybrids are intermediate parental resemble Hsp concentrations Hsp70 protein electromorphs.