QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Garbuz, D. Articles by Zatsepina, O. G. Search for Related Content PubMed PubMed Citation Articles by Garbuz, D. Articles by Zatsepina, O. G.

Evolution of thermotolerance and the heat-shock response: evidence from inter/intraspecific comparison and interspecific hybridization in the virilis species group of Drosophila. I. Thermal phenotype

David Garbuz¹, Michael B. Evgenev^1,2, Martin E. Feder^3,4,* and Olga G. Zatsepina¹

¹ Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, 117984 Moscow, Russia
² Institute of Cell Biophysics, Puschino, Russia
³ Department of Organismal Biology & Anatomy
⁴ The Committee on Evolutionary Biology, The University of Chicago, 1027 E. 57th Street, Chicago, IL 60637, USA

View larger version (33K): [in a new window]   Fig. 1. Inter- and intraspecific variation of basal thermotolerance in D. virilis group species. Strain 160, although D. virilis, is a marker strain with at least one known recessive mutation on each chromosome; all other strains are wild-type. See Table 1 for additional descriptions of all strains. Data for D. lummei strain 200 and D. virilis strains 9, 160 and 1433 are replotted from Garbuz et al. (2002), in which D. virilis strain 1433 is mistakenly labeled strain 1590.

View larger version (34K): [in a new window]   Fig. 2. Effect of species, parental genotype and pre-treatment (PT) on (A) basal and (B) inducible thermotolerance. Data for D. lummei strain 200 and D. virilis strain 9 are replotted from Garbuz et al. (2002). In B, two-headed arrows represent the change in thermotolerance from basal levels (broken lines) to tolerance after PT (solid lines). In pretreated D. virilis strain 9 (solid red), PT was 30 min at 35°C, 36°C or 37°C. In pretreated D. lummei strain 200 (solid blue), PT was 30 min at 35°C (as shown), 36°C (not shown) or 37°C (not shown). No D. lummei pre-treated at 36°C or 37°C survived the ensuing heat shock. The inset indicates color coding for reciprocal hybrids of D. lummei strain 200 and D. virilis strain 9 and the species identity of female (F) and male (M) parent. Broken and solid lines indicate thermotolerance with and without pretreatment, respectively, after 35°C PT for 30 min. Hybrids also underwent PT at 36°C for 30 min with heat shock either following immediately (triangles) or 3 h later (squares); these symbols signify the LT50s.

View larger version (28K): [in a new window]   Fig. 5. Variation in Hsp70 concentration in salivary glands due to species, strain and heat-shock conditions. All determinations are for equivalent amounts of total protein extracted 3 h after a 30-min heat shock and are from immunoblots with 7FB, an antibody recognizing only the 70-kDa inducible Hsp70 family member in D. melanogaster (see Materials and methods). (A) Effect of heat-shock temperature on Hsp70 levels in D. virilis strains (solid lines) and D. lummei strains (broken lines). Symbols represent the mean densitometric signal ± 1 S.E.M. from at least five independent immunoblots. All data are normalized to the densitometric signal for equivalent amounts of protein extracted from D. melanogaster salivary glands 1 h after a 30-min heat shock at 37.5°C. (B) Effect of heat-shock temperature on Hsp70 levels in D. novamexicana (solid line) and D. texana (broken line). Data are standardized and plotted as for A. (C) 7FB-immunoblots of Hsp70 for various species and strains. Each pair of lanes corresponds to 40°C and 41°C heat shock. See fig. 2 in Garbuz et al. (2002) for additional determinations of Hsp70 levels.

View larger version (13K): [in a new window]   Fig. 6. Immunoblots of Hsp70 and Hsp70 family members in D. virilis strain 9, D. lummei strain 200 and their hybrid. In Fig. 4, the box in the Hsp70 region for D. lummei strain 1109 represents the region of the present figure. Data for the parental strains are repeated from Garbuz et al. (2002) and are included to facilitate comparison with data for hybrids. Primary antibody 7FB recognizes only the 70-kDa inducible Hsp70 family member in D. melanogaster; primary antibody 7.10.3 recognizes all Hsp70 family members (see Materials and methods). Heat shock was 38°C for 30 min, with 3 h recovery at 25°C before lysis. In the right-hand column, blue represents constitutively present proteins recognized by 7.10.3 only, red represents inducible (i.e. undetectable in glands not undergoing heat shock) proteins recognized by both 7.10.3 and 7FB, and green represents inducible proteins recognized by 7.10.3 only.

View larger version (84K): [in a new window]   Fig. 3. One-dimensional electrophoretic separation of 35S-labeled proteins after 30-min heat shock. vir refers to D. virilis, and lum refers to D. lummei; numbers represent strains. Size markers refer to expected molecular masses of Drosophila heat-shock proteins.

View larger version (66K): [in a new window]   Fig. 4. Two-dimensional electrophoretic separation of 35S-labeled proteins after 30-min heat shock at 40.5°C and 3 h of recovery at 25°C. Species and strains are noted. Labels refer to molecular masses of Drosophila heat-shock proteins; 70c represents constitutively expressed Hsp70 family members. The box in the Hsp70 region for D. lummei strain 1109 represents the region detailed in Fig. 6. See Garbuz et al. (2002) for additional results after less-severe heat shock.

View larger version (39K): [in a new window]   Fig. 7. Effect of species, strain and thermal regime on hsp70 (above) and actin (below) mRNA levels.

View larger version (59K): [in a new window]   Fig. 8. Electrophoretic mobility-shift assay for HSF (heat-shock factor) activation at various temperatures in D. virilis strain 9 and D. lummei strain 200. Appearance of a high-molecular-mass HSF complex indicates HSF activation.