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Divergence between two Antarctic species of the ciliate Euplotes , E. focardii and E. nobilii , in the expression of heat‐shock protein 70 genes
Author(s) -
La Terza A.,
Papa G.,
Miceli C.,
Luporini P.
Publication year - 2001
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1046/j.1365-294x.2001.01242.x
Subject(s) - biology , macronucleus , ciliate , gene , heat shock protein , adaptation (eye) , hsp70 , genetics , microbiology and biotechnology , functional divergence , psychrophile , gene expression , gene family , bacteria , neuroscience
Most organisms oppose many environmental stresses by rapidly enhancing synthesis of the highly conserved Hsp70 family of heat‐shock proteins. Two ciliates which are endemic in Antarctic coastal seawater, Euplotes focardii and E. nobilii , and behave as psychrophile and psychrotroph micro‐organisms, respectively, revealed a divergence in the capacity to respond to thermal stress with an activation of the transcription of their hsp70 genes. In both species, these genes were shown to be represented by thousands of copies in the cell’s somatic functional nucleus (macronucleus). However, while a strong transcriptional activity of hsp70 genes was induced in E. nobilii cells transferred from 4 to 20 °C, a much smaller increase was revealed in heat‐shocked cells of E. focardii . These findings suggest a closer adaptation to the stably cold Antarctic waters in the genetic response of E. focardii to thermal stress.