The time course of development and loss of thermotolerance in Chinese hamster ovary cells exposed to 42 degrees was determined. The influence of pH on the heat sensitivity of normal and thermotolerant cells was examined. Exposure of cells to single graded heat treatments at pH 7.4 resulted in a decrease in survival to 5 to 10% after 3 to 4 hr treatment. Continued heating for an additional 4 to ...

In most flowering plant species, pollination and fertilization occur during the hot summer, so plants must have evolved a mechanism that ensures normal growth of their pollen tubes at high temperatures. Despite its importance to plant reproduction, little is known about the molecular basis of thermotolerance in pollen tubes. Here we report the identification and characterization of a novel Arab...

Repeat sequences, especially mobile elements, make up large portions of most eukaryotic genomes and provide enormous, albeit commonly underappreciated, evolutionary potential. We analyzed repeatomes of Drosophila melanogaster that have been diverging in response to a microclimate contrast in Evolution Canyon (Mount Carmel, Israel), a natural evolutionary laboratory with two abutting slopes at a...

Levels of HSP70 protein of fifth-instar codling moth [Cydia pomonella (L.) (Lepidoptera: Tortricidae)] are determined after conditioning at 35 C for different times and also after recovery at 22 C. Protein samples from larvae conditioned for different times are separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis electrophoresis. Sub-lethal thermal conditioning at 35 C for 40...

BACKGROUND: Cocoa, one of the richest dietary sources polyphenols has been studied for its health promoting effects, but how long-term consumption cocoa affects age-associated and lifespan is not well defined. OBJECTIVE: The objective this study was to determine effects on in C. elegans METHODS: standard E. coli OP50 diet wild type supplemented with powder starting from L1 stage until they die....

A ciprotloxacin resi stant mutant (Cf) of Rhizobium legulIlinossarulll bv phaseoli USDA 2695 which nodulates common bean plants (Phaseolus vulgaris L) was isolated after nitrous acid mutagenesis. Another m tant resistant to nalidi xic acid (NaIR) was isolated spontaneously. Both mutants showed thermotolerance as evident by their abi lity to grow at elevated (40°C) temperature, although the wi l...

A new member of the yeast yAP family, designated YAP2, has been isolated and characterized. The protein displays a high homology with the DNA-binding domain of yAP-1, which contains a basic DNA-binding domain and leucine zipper motif and binds in vitro to the same cis-element. Growth arrest of yeast caused by low concentrations of 1,10-phenanthroline, resulting in zinc and/or iron deprivation, ...

The heat shock protein Hsp104 of the yeast Saccharomyces cerevisiae plays a key role in promoting survival at extreme temperatures. We found that when diverse higher plant species are exposed to high temperatures they accumulate proteins that are antigenically related to Hsp104. We isolated a cDNA corresponding to one of these proteins from Arabidopsis. The protein, AtHSP101, is 43% identical t...