Biomaterial Database

Deleterious consequences of Hsp70 overexpression in Drosophila melanogaster larvae. 1997

R A Krebs, and M E Feder

Department of Organismal Biology and Anatomy, University of Chicago, IL 60637, USA. r-krebs@uchicago.edu

We compared transgenic Drosophila larvae varying in hsp70 copy number to assess the consequences of Hsp70 overexpression for growth and development after heat shock. Exposure to a mildly elevated temperature (36 degrees C) induced expression of Hsp70 (and presumably other heat shock proteins) and improved tolerance of more severe heat stress, 38.5-39.5 degrees C. We examined this pattern in two independently derived pairs of extra-copy and excision strains that differed primarily in hsp70 copy number (with 22 and 10 copies, respectively). Extra-copy larvae produced more Hsp70 in response to high temperature than did excision larvae, but surpassed the excision strain in survival only immediately after thermal stress. Excision larvae survived to adulthood at higher proportions than did extra-copy larvae and grew more rapidly after thermal stress. Furthermore, multiple pretreatment reduced survival of 1st-instar extra-copy larvae, but did not affect the corresponding excision strain. While extra Hsp70 provides additional protection against the immediate damage from heat stress, abnormally high concentrations can decrease growth, development and survival to adulthood.

UI	MeSH Term	Description	Entries
D007814	Larva	Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.	Maggots,Tadpoles,Larvae,Maggot,Tadpole
D008297	Male		Males
D002875	Chromosomes	In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Chromosome
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D005260	Female		Females
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013312	Stress, Physiological	The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.	Biotic Stress,Metabolic Stress,Physiological Stress,Abiotic Stress,Abiotic Stress Reaction,Abiotic Stress Response,Biological Stress,Metabolic Stress Response,Physiological Stress Reaction,Physiological Stress Reactivity,Physiological Stress Response,Abiotic Stress Reactions,Abiotic Stress Responses,Abiotic Stresses,Biological Stresses,Biotic Stresses,Metabolic Stress Responses,Metabolic Stresses,Physiological Stress Reactions,Physiological Stress Responses,Physiological Stresses,Reaction, Abiotic Stress,Reactions, Abiotic Stress,Response, Abiotic Stress,Response, Metabolic Stress,Stress Reaction, Physiological,Stress Response, Metabolic,Stress Response, Physiological,Stress, Abiotic,Stress, Biological,Stress, Biotic,Stress, Metabolic
D017344	Genes, Insect	The functional hereditary units of INSECTS.	Insect Genes,Gene, Insect,Insect Gene