COMPARING DIFFERENT MEASURES OF HEAT-RESISTANCE IN SELECTED LINES OF DROSOPHILA-MELANOGASTER

Citation
Aa. Hoffmann et al., COMPARING DIFFERENT MEASURES OF HEAT-RESISTANCE IN SELECTED LINES OF DROSOPHILA-MELANOGASTER, Journal of insect physiology, 43(4), 1997, pp. 393-405
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Entomology
ISSN journal
0022-1910
Volume
43
Issue
4
Year of publication
1997
Pages
393 - 405
Database
ISI
SICI code
0022-1910(1997)43:4<393:CDMOHI>2.0.ZU;2-C
Abstract
Lines of the fly Drosophila melanogaster were selected for increased k nockdown resistance to heat (39 degrees C) in a long tube. One set of lines was selected following prior heat hardening (1 h at 37 degrees C ) and another without hardening, Each set consisted of three replicate selection lines and three unselected controls, Lines were tested for correlated responses to selection, in order to define the nature of kn ockdown resistance, Selection had a Large effect on knockdown resistan ce, but selected lines did not differ from controls for knockdown time in small vials, survival, or recovery time following exposure to heat , Selection with and without hardening influenced the hardening respon se in the long tube, but not in small vial assays of resistance, The h ardened selection lines had decreased resistance to ethanol and a redu ced dry weight, whereas the non-hardened lines did not show these chan ges, The same correlated responses were also evident in two generation experiments on unselected flies, Both sets of lines showed a reductio n in activity when tested at 37 degrees C, but not at 25 degrees C, Th ese results indicate that different measures of heat resistance are su rprisingly unrelated, and suggest that subtle features of the selectiv e environment influence responses and correlated responses to selectio n. (C) 1997 Elsevier Science Ltd.