Dauer formation induced by high temperatures in Caenorhabditis elegans

Citation
M. Ailion et Jh. Thomas, Dauer formation induced by high temperatures in Caenorhabditis elegans, GENETICS, 156(3), 2000, pp. 1047-1067
Citations number
76
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology,"Molecular Biology & Genetics
Journal title
GENETICS
ISSN journal
0016-6731 → ACNP
Volume
156
Issue
3
Year of publication
2000
Pages
1047 - 1067
Database
ISI
SICI code
0016-6731(200011)156:3<1047:DFIBHT>2.0.ZU;2-R
Abstract
Dauer formation in Caenorhabditis elegans is regulated by several environme ntal stimuli, including a pheromone and temperature. Dauer formation is mod erately induced as the growth temperature increases from 15 degrees to 25 d egrees. Here we show that dauer formation is very strongly induced at a tem perature of 27 degrees in both wild-type animals and mutants such as unc-64 , unc-31, and unc-3, which do not form dauers at 25 degrees. A 27 degrees t emperature stimulus is sufficient to induce dauer formation in wild-type an imals independent of pheromone. Analysis of previously described dauer muta nts at 27 degrees reveals a number of surprising results. Several classes o f mutants (dyf, daf-3 tax-4, and tax-2) that are defective in dauer formati on at lower temperatures reverse their phenotypes at 27 degrees and form da uers constitutively. Epistasis experiments place unc-64 and unc-31 at a dif ferent position in the dauer pathway from unc-3 We also uncover new branche s of the dauer pathway at 27 degrees that are not detected at 25 degrees. W e show that epistatic gene inter actions can show both quantitative and qua litative differences depending on environmental conditions. Finally, ive di scuss some of the possible ecological implications of dauer induction by hi gh temperatures.