title: Characterization of the heat shock response in the gills of sea lampreys and a brook lamprey at different intervals of their life cycles.
abstract: The heat shock response (HSR) was characterized in the gills of two lamprey species that differ with respect to their adult life history. In vivo labelling with [35S]methionine revealed an enhanced synthesis of heat shock proteins (HSPs) having approximate molecular weights of 70 kDa (HSP70) and 90 kDa (HSP90) following heat treatment. Induction of the HSR occurred in larval lampreys (ammocoetes) following temperature elevations of 13-16 degrees C for the parasitic species, the sea lamprey (Petromyzon marinus) and 16-20 degrees C for the nonparasitic species, the brook lamprey (Lampetra appendix). The case in L. appendix represents the greatest increase in temperature required to induce the HSR in gill tissue among aquatic poikilotherms studied to data and induction occurs within a temperature range (25-29 degrees C) not normally experienced by these animals. Western blotting detected the presence of 70 and 90 kDa HSPs and HSP70 levels were greater in post-metamorphic L. appendix than in ammocoetes both before and after heat shock. The HSR of lampreys appears to be induced during times of emergency when large, rapid temperature increases are experienced. The high set-point temperature for induction of the response may be a consequence of both the environments they presently inhabit and their experiences during evolution.
authors.affiliation: Division of Life Sciences, University of Toronto at Scarborough, Ontario, Canada.
authors.forename: L A
authors.initials: LA
authors.lastname: Wood
authors.forename: I R
authors.initials: IR
authors.lastname: Brown
authors.forename: J H
authors.initials: JH
authors.lastname: Youson
mesh_terms: D000818:Animals; D005880:Gills / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D018869:Heat-Shock Response / Q000502:physiology*; D007798:Lampreys / Q000145:classification / Q000254:growth & development / Q000502:physiology*; D008018:Life Cycle Stages; D013045:Species Specificity; D013696:Temperature
chemical_list: D006360:Heat-Shock Proteins