Behavioral and Biochemical Defects in Temperature-Sensitive Acetylcholinesterase Mutants of DROSOPHILA MELANOGASTER
AUTOR(ES)
Hall, Jeffrey C.
RESUMO
Temperature-sensitive (ts) mutants of the Ace gene, which codes for acetylcholinesterase (AChE) in Drosophila melanogaster, were analyzed for defects in viability, behavior and function of the enzyme. The use of heat-sensitive and cold-sensitive mutations permited the function of AChE in the nervous system to be analyzed temporally. All ts mutations were lethal, or nearly so, when animals expressing them were subjected to restrictive temperatures during late embryonic and very early larval stages. Heat treatments to Ace-ts mid- and late larvae had little effect on the behavior of these animals or on the viability or behavior of the eventual adults. Heat-sensitive mutants exposed to nonpermissive temperatures as pupae, by contrast, had severe defects in phototaxis and locomotor activity as adults. AChE extracted from adult ts mutants that had developed at a permissive temperature were abnormally heat labile, and they had reduced substrate affinity when assayed at restrictive temperatures. However, enzyme activity did not decline during exposure of heat-sensitive adults to high temperatures even though such treatments caused decrements in phototaxis (29°) and, eventually, cessation of movement (31°). The cold-sensitive mutant also produced readily detectable levels of AChE when exposed to a restrictive temperature during the early developmental stage when this mutation causes almost complete lethality. We suggest that the relationship among the genetic, biochemical and neurobiological defects in these mutants may involve more than merely temperature-sensitive catalytic functions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1219310Documentos Relacionados
- Neurophysiological defects in temperature-sensitive paralytic mutants of Drosophila melanogaster.
- Isolation of Recessive Third-Chromosome Temperature-Sensitive Mutants in DROSOPHILA MELANOGASTER
- Biochemical characterization of temperature-sensitive rabies virus mutants.
- Maturation Defects in Temperature-sensitive Mutants of Sindbis Virus 1
- The Effects of Increased Temperature on Electroretinograms of Temperature-Sensitive Paralysis Mutants of Drosophila melanogaster*