Genomes and Genes
Gene Symbol: Hsp27
Description: Heat shock protein 27
Alias: 27K, CG4466, Dhsp27, DmHSP27, DmHsp27, Dmel\CG4466, HSP27, HSP28, Hsp 27, Hsp28, anon-WO0140519.69, hsp 27, hsp-27, hsp26, hsp27, hsp27/26, hsp28, small hsp locus 67B, CG4466-PA, Hsp 27, Hsp27-PA, heat shock protein 237, heat shock protein 27, heat shock protein hsp27, protein 27
Species: fruit fly
- Germline transformation used to define key features of heat-shock response elementsH Xiao
Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853
Science 239:1139-42. 1988..These and additional analyses indicate that the heat-shock regulatory element includes sequences beyond the 14-base pair HSE and may be better described as a dimer of a 10-base pair sequence, NTTCNNGAAN...
- A regulatory upstream promoter element in the Drosophila hsp 70 heat-shock geneH R Pelham
Cell 30:517-28. 1982..It seems that the upstream element of the hsp 70 promoter is analogous to that of other promoters, but is only functional in heat-shocked cells...
- Binding of heat shock factor to and transcriptional activation of heat shock genes in DrosophilaM Fernandes
Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853, USA
Nucleic Acids Res 23:4799-804. 1995..This last result suggests that close proximity of HSEs for cooperative binding of HSF is a result of protein-protein interactions near the point of DNA contact...
- Small stress proteins as novel regulators of apoptosis. Heat shock protein 27 blocks Fas/APO-1- and staurosporine-induced cell deathP Mehlen
Laboratoire du Stress Cellulaire, Centre de Genetique Moleculaire et Cellulaire, CNRS UMR 5534, Universite Claude Bernard Lyon I, 69622 Villeurbanne, France
J Biol Chem 271:16510-4. 1996..also report that the expression of small stress proteins from different species, such as human hsp27, Drosophila Dhsp27, or human alphaB-crystallin, confers resistance to apoptotic cell death induced by staurosporine, a protein kinase ..
- Properties of ecdysteroid receptors from diverse insect species in a heterologous cell culture system--a basis for screening novel insecticidal candidatesJoshua M Beatty
Center for Biotechnology, Genomics, and Health Research, University of North Carolina at Greensboro, NC 27402, USA
FEBS J 276:3087-98. 2009..decemlineata USP than with D. melanogaster USP. Generally, the species-based differences validate the use of the cell culture assay screen for novel agonists and potentiators as species-targeted insecticidal candidates...
- Cell-specific heat-shock induction of Hsp23 in the eye of Drosophila melanogasterR Marin
Centre deRecherche du CHUL, Universite Laval, Ste Foy, Quebec, Canada
Cell Stress Chaperones 1:40-6. 1996The expression of two small heat shock proteins (sHsp), Hsp23 and Hsp27, was examined by immunological approaches in the eye of Drosophila melanogaster...
- Co-localization of Polycomb protein and GAGA factor on regulatory elements responsible for the maintenance of homeotic gene expressionH Strutt
ZMBH, University of Heidelberg, Germany
EMBO J 16:3621-32. 1997..We propose that GAGA factor binds constitutively to regulatory elements in the bithorax complex, which function both as PREs and as trithorax group response elements...
- Regulation of heat shock gene induction and expression during Drosophila developmentS Michaud
Laboratoire de génétique cellulaire et developpmentale, RSVS, Universite Laval, Sainte Foy, Quebec, Canada
Cell Mol Life Sci 53:104-13. 1997..During development, each of the four members of the small heat shock protein family (Hsp27, Hsp26 Hsp23 and Hsp22), which are coordinately induced in response to a heat stress, shows a specific pattern of ..
- HSF recruitment and loss at most Drosophila heat shock loci is coordinated and depends on proximal promoter sequencesL S Shopland
Section of Biochemistry, Molecular and Cell Biology, 417 Biotechnology Building, Cornell University, Ithaca, NY 14853, USA
Chromosoma 105:158-71. 1996..Finally, the distribution of the heat shock protein HSP70 is examined for its role in regulating the attenuated response of HSF to heat shock...
- Human hsp27, Drosophila hsp27 and human alphaB-crystallin expression-mediated increase in glutathione is essential for the protective activity of these proteins against TNFalpha-induced cell deathP Mehlen
Laboratoire du Stress Cellulaire, Centre de Génétique Moléculaire etCellulaire, CNRS UMR 5534, France
EMBO J 15:2695-706. 1996..Recently, we have shown that the expression of shsp from different species, such as human hsp27, Drosophila hsp27 or human alphaB-crystallin protected murine L929 cells against cell death induced by tumor ..
- Characterization of an EcR/USP heterodimer target site that mediates ecdysone responsiveness of the Drosophila Lsp-2 geneC Antoniewski
Institut Jacques Monod, Centre National de la Recherche Scientifique and Université de Paris 7, France
Mol Gen Genet 249:545-56. 1995..affinity of the Lsp-2 EcRE for the ecdysone receptor complex is comparable to that of the canonical EcRE of the hsp27 gene and is at least 4-fold greater than that of Fbp1, another fat body-specific Drosophila gene...
- Rapid changes in Drosophila transcription after an instantaneous heat shockT O'BRIEN
Section of Genetics and Development, Cornell University, Ithaca, New York 14853
Mol Cell Biol 13:3456-63. 1993..A similar rapid induction was found for the small heat shock genes (hsp22, hsp23, hsp26, and hsp27)...
- Transcriptional regulation in Drosophila during heat shock: a nuclear run-on analysisJ Vazquez
Departement de Biologie Moleculaire, Universite de Geneve, Switzerland
Chromosoma 102:233-48. 1993..2 polymerases per gene). Engaged but paused RNA polymerase molecules were found at the hsp70 and hsp26 genes, but not at the other heat shock genes...
- Heat shock gene expression and development. I. An overview of fungal, plant, and poikilothermic animal developmental systemsJ J Heikkila
Department of Biology, University of Waterloo, Ontario, Canada
Dev Genet 14:1-5. 1993
- Heat shock proteins in three related Drosophila species belonging to the obscura groupM D Molto
Department of Genetics, Faculty of Biological Sciences, University of Valencia, Spain
Experientia 49:54-6. 1993..By means of in situ hybridization using D. melanogaster probes for the small hsp genes, it was inferred that the small hsp genes of the obscura group species are clustered at the 27A locus in all three species...
- Analysis of the resistance to heat and hydrogen peroxide stresses in COS cells transiently expressing wild type or deletion mutants of the Drosophila 27-kDa heat-shock proteinP Mehlen
Molecular and Cellular Genetics, CNRS UMR 106, Claude Bernard University, Lyon, France
Eur J Biochem 215:277-84. 1993The Drosophila melanogaster small heat-shock protein, hsp27 (Dhsp27) belongs to a family of polypeptides which shares a sequence related to alpha-crystallin and which protect cell against heat shock...
- Cell-specific expression and heat-shock induction of Hsps during spermatogenesis in Drosophila melanogasterS Michaud
CHUL Research Center CHUQ, Universite Laval, Ste Foy, Quebec, Canada
J Cell Sci 110:1989-97. 1997The developmental and heat-shock-induced expression of two small heat-shock proteins (Hsp23 and Hsp27) was investigated during spermatogenesis in Drosophila melanogaster...
- Systematic gain-of-function genetics in DrosophilaP Rørth
Department of Embryology, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, MD 21210, USA
Development 125:1049-57. 1998..These studies demonstrate the ability of the modular misexpression system to identify developmentally important genes and suggest that it will be generally useful for genetic interaction screens...
- Aging-specific expression of Drosophila hsp22V King
Department of Biological Sciences, University of Southern California, University Park, Los Angeles, California, 90089 1340, USA
Dev Biol 207:107-18. 1999..Aging-specific induction of hsp22 is discussed with regard to current evolutionary theories of aging...
- The effect of neuronal expression of heat shock proteins 26 and 27 on lifespan, neurodegeneration, and apoptosis in DrosophilaPin Chao Liao
Department of Life Science and Institute of Biotechnology, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
Biochem Biophys Res Commun 376:637-41. 2008..Our previous study reported that ubiquitous expression of hsp26 or hsp27 extended Drosophila lifespan...
- The Hsp27 gene is not required for Drosophila development but its activity is associated with starvation resistanceXinming Hao
Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 2131, USA
Cell Stress Chaperones 12:364-72. 2007..We investigated a fruit fly gene encoding a small heat shock protein, Hsp27, to determine if it functions in stress response of Drosophila melanogaster. A knockout Hsp27 allele was generated...
- Drosophila Pgc protein inhibits P-TEFb recruitment to chromatin in primordial germ cellsKazuko Hanyu-Nakamura
Laboratory for Germline Development, RIKEN Center for Developmental Biology, Kobe, Hyogo 650 0047, Japan
Nature 451:730-3. 2008..Thus, inhibition of P-TEFb is probably a common mechanism during germ cell specification in the disparate organisms C. elegans and Drosophila...
- Intranuclear distribution and local dynamics of RNA polymerase II during transcription activationJie Yao
School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
Mol Cell 28:978-90. 2007..Pol II at highly transcribed developmental loci exhibits dynamics resembling combinations of these Hsp70 transcription modes...
- Multiple-stress analysis for isolation of Drosophila longevity genesHorng Dar Wang
Division of Biology 156 29, California Institute of Technology, Pasadena, CA 91125, USA
Proc Natl Acad Sci U S A 101:12610-5. 2004..Two of these, hsp26 and hsp27, were chosen to test for their effects on lifespan by generating transgenic lines and by using the upstream ..
- Ecdysone receptor-dependent gene regulation mediates histone poly(ADP-ribosyl)ationShun Sawatsubashi
The Institute of Molecular and Cellular Biosciences, University of Tokyo, 1 1 1 Yayoi, Bunkyo ku, Tokyo 113 0032, Japan
Biochem Biophys Res Commun 320:268-72. 2004..Our results indicated that EcR-mediated gene regulation may be coupled with chromatin modification through poly(ADP-ribosyl)ation...
- Quantitative trait loci affecting natural variation in Drosophila longevityGretchen L Geiger-Thornsberry
Department of Genetics, Box 7614, North Carolina State University, Raleigh 27695, USA
Mech Ageing Dev 125:179-89. 2004..Quantitative complementation tests are therefore useful for identifying QTL contributing to segregating genetic variation in life span in nature...
- Purification of Drosophila melanogaster ultraspiracle protein and analysis of its A/B region-dependent dimerization behavior in vitroGrzegorz Rymarczyk
Institute of Organic Chemistry, Biochemistry and Biotechnology, Division of Biochemistry, Wrocław University of Technology, Wybrzeze Wyspianskiego 27, 50 370 Wrocław, Poland
Biol Chem 384:59-69. 2003..It was demonstrated that the recombinant receptor specifically binds the ecdysone response element of the hsp27 gene promoter (hsp27EcRE)...
- Induction of the early-late Ddc gene during Drosophila metamorphosis by the ecdysone receptorLi Chen
Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
Mech Dev 114:95-107. 2002..the Ddc EcRE for the ecdysone receptor complex was at least four-fold less than that of the canonical EcRE of the hsp27 gene...
- Timing and targeting of P-element local transposition in the male germline cells of Drosophila melanogasterBenjamin Timakov
Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 2131, USA
Genetics 160:1011-22. 2002..Our analysis shows that local transposition of the P element is highly regulated, displaying a cell-type specificity and a target specificity...
- A Drosophila melanogaster strain from sub-equatorial Africa has exceptional thermotolerance but decreased Hsp70 expressionO G Zatsepina
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Street 32, 117984 Moscow, Russia
J Exp Biol 204:1869-81. 2001..We hypothesize that the reduced Hsp70 expression in a Drosophila melanogaster strain living chronically at intermediate temperatures may represent an evolved suppression of the deleterious phenotypes of Hsp70...
- Analysis of Usp DNA binding domain targeting reveals critical determinants of the ecdysone receptor complex interaction with the response elementI Grad
Institute of Organic Chemistry, Biochemistry and Biotechnology, Division of Biochemistry, Wroclaw University of Technology, Poland
Eur J Biochem 268:3751-8. 2001..a specific anchor that preferentially binds the 5' half-site of the pseudo-palindromic response element from the hsp27 gene promoter and thus locates the heterocomplex in the defined orientation...
- Increased hsp22 RNA levels in Drosophila lines genetically selected for increased longevityR Kurapati
Department of Biological Sciences, University of Southern California, Los Angeles 90089 1340, USA
J Gerontol A Biol Sci Med Sci 55:B552-9. 2000..Thus increased hsp22 and hsp23 RNA levels correlate with the increased life span and increased stress resistance of the genetically selected O lines...
- Polarity of the ecdysone receptor complex interaction with the palindromic response element from the hsp27 gene promoterA Niedziela-Majka
Institute of Organic Chemistry, Division of Biochemistry, Wroctaw University of Technology, Poland
Eur J Biochem 267:507-19. 2000..EcR and Usp DNA-binding domains (EcRDBD and UspDBD, respectively) with the palindromic response element from the hsp27 gene promoter (hsp27pal)...
- Chromosomal homologies between Drosophila lebanonensis and D. melanogaster determined by in situ hybridizationM Papaceit
Departament de Genetica, Facultat de Biologia, Universitat de Barcelona, Spain
Chromosoma 102:361-8. 1993..Six probes correspond to known genes from D. melanogaster (RpII215, H3-H4, MHC, hsp28/23, hsp83, hsp70), four probes are clones isolated from a D...
- ATP-dependent nucleosome disruption at a heat-shock promoter mediated by binding of GAGA transcription factorT Tsukiyama
Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
Nature 367:525-32. 1994..ATP hydrolysis facilitates this process, suggesting that an energy-dependent pathway is involved in chromatin remodelling...
- Locus 67B of Drosophila melanogaster contains seven, not four, closely related heat shock genesA Ayme
EMBO J 4:2949-54. 1985..We conclude that genes 1, 2 and 3 are also heat shock genes. Therefore, the locus 67B contains seven, not four, small heat shock genes...
- Functional redundancy in the tissue-specific enhancer of the Drosophila Sgs-4 geneT A Jongens
Department of Molecular Biology, University of California, Berkeley 94720
EMBO J 7:2559-67. 1988..For at least this regulatory activity the enhancer is internally redundant. Any pairwise combination of the three elements is sufficient to direct salivary gland expression, although none of the three can act alone...
- Ecdysteroid-regulated heat-shock gene expression during Drosophila melanogaster developmentS R Thomas
Dev Biol 115:434-8. 1986..These results are consistent with the induction of the hsp 83, 28, and 26 genes by ecdysteroid at several developmental stages...
- Puffs and gene regulation--molecular insights into the Drosophila ecdysone regulatory hierarchyC S Thummel
Howard Hughes Medical Institute, Department of Human Genetics, University of Utah Medical Center, Salt Lake City 84132
Bioessays 12:561-8. 1990..Proteins encoded by two of the early genes bind to both early and late ecdysone-induced puffs, implying that they are key regulators in the hierarchy...
- Developmental expression of Drosophila melanogaster small heat-shock proteinsC Haass
ZMBH Molekulare Genetik, University of Heidelberg, FRG
J Cell Sci 96:413-8. 1990....
- Prompt heat-shock and heat-shifted proteins associated with the nuclear matrix-intermediate filament scaffold in Drosophila melanogaster cellsD A Ornelles
Department of Biology, Princeton University, New Jersey 08544
J Cell Sci 95:393-404. 1990..The prompt HS proteins can be distinguished clearly from heat-shifted proteins by several criteria. Also, the prompt HS proteins are distinct from the heat-insensitive viral proteins of a persistent virus (HPS-1)...
- Ecdysterone regulatory elements function as both transcriptional activators and repressorsL Dobens
Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
Mol Cell Biol 11:1846-53. 1991..23-bp ecdysterone regulatory element (EcRE), derived from the upstream region of the Drosophila melanogaster hsp27 gene, was inserted adjacent to the herpes simplex virus thymidine kinase promoter fused to a bacterial gene for ..
- Genes for Drosophila small heat shock proteins are regulated differently by ecdysteroneJ Amin
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Florida 33101
Mol Cell Biol 11:5937-44. 1991Genes for small heat shock proteins (hsp27 to hsp22) are activated in late third-instar larvae of Drosophila melanogaster in the absence of heat stress...
- The Drosophila EcR gene encodes an ecdysone receptor, a new member of the steroid receptor superfamilyM R Koelle
Department of Biochemistry, Stanford University Medical Center, California 94305
Cell 67:59-77. 1991..As expected, EcR is nuclear and found in all ecdysone target tissues examined. Furthermore, the EcR gene is expressed at each developmental stage marked by a pulse of ecdysone...
- Inactivation of mRNA cap-binding protein complex in Drosophila melanogaster embryos under heat shockJ M Zapata
Centro de Biologia Molecular, Consejo Superior de Investigaciones Cientificas, Madrid, Spain
J Biol Chem 266:16007-14. 1991..Together, the above results suggest that some modification leading to the disruption of Drosophila CBP complex may account, at least to some extent, for the mRNA discrimination established in heat-shocked Drosophila embryos...
- Expression of Drosophila's 27 kDa heat shock protein into rodent cells confers thermal resistanceE Rollet
Laboratoire de Genetique Cellulaire et Moleculaire, CHUL, Ste Foy, QC, Canada
Biochem Biophys Res Commun 185:116-20. 1992The role of hsp27, one of Drosophila melanogaster's small heat shock proteins, in the process of thermotolerance was investigated...
- Messenger RNA in heat-shocked Drosophila cellsA Spradling
J Mol Biol 109:559-87. 1977
- Genetic mapping of the coding regions for three heat-shock proteins in Drosophila melanogasterN S Peterson
Genetics 92:891-902. 1979..All three map to a region on chromosome 3L that includes only one heat-shock puff, designated as 67B. The results imply that the genes coding for at least three heat-shock proteins are included within the 67B region...
- The Drosophila hsp70 message is rapidly degraded at normal temperatures and stabilized by heat shockR Petersen
Department of Molecular Genetics and Cell Biology, University of Chicago, IL 60637
Gene 72:161-8. 1988..Apparently, the hsp70 message is inherently unstable. During heat-shock, degradation of the message is suspended; during recovery degradation is restored...
- Suppression of heat-shock protein synthesis by short-chain fatty acids and alcoholsR J Munks
Department of Anatomy, University of Birmingham Medical School, UK
Biochim Biophys Acta 1223:23-8. 1994..Suppression was accompanied by severely reduced levels of both hsp70 mRNA and active heat-shock factor (HSF). We conclude that the inhibitors act by suppressing the initiation of transcription of heat-shock genes...
- Polytene chromosomes show normal gene activity but some mRNAs are abnormally accumulated in the pseudonurse cell nuclei of Drosophila melanogaster otu mutantsT I Heino
Department of Biosciences, Division of Genetics, P O Box 56, FIN 00014 University of Helsinki, Finland
Chromosoma 104:44-55. 1995..We suggest that the otu mRNA remains partly attached to the polytene chromosome template after transcription and discuss the effects of this phenomenon on polytenisation of the PNC chromosomes...
- Short transcripts of the ternary complex provide insight into RNA polymerase II elongational pausingE B Rasmussen
Section of Biochemistry Molecular and Cell Biology, Cornell University, Ithaca New York, 14853, USA
J Mol Biol 252:522-35. 1995..These included two of the small heat shock genes (hsp26 and hsp27) and two metabolic genes (Gapdh-1 and Gapdh-2), where paused polymerases were thought to be present, plus two ..
- Identification and characterization of a Drosophila nuclear receptor with the ability to inhibit the ecdysone responseA C Zelhof
Department of Biology, University of California, San Diego, La Jolla 92093, USA
Proc Natl Acad Sci U S A 92:10477-81. 1995..XR78E/F has its highest expression in third-instar larvae and prepupae. These experiments suggest that XR78E/F may play a regulatory role in the transcriptional cascade triggered by the hormone ecdysone in Drosophila...
- Accumulation of a specific subset of D. melanogaster heat shock mRNAs in normal development without heat shockJ L Zimmerman
Cell 32:1161-70. 1983..melanogaster, messenger RNAs for three of the seven heat shock proteins (hsp83, hsp28 and hsp26) accumulate in adult ovaries and are abundant in embryos until blastoderm...
- Two protein-binding sites in chromatin implicated in the activation of heat-shock genesC Wu
Nature 309:229-34. 1984..The pattern of resistance before and after induction of gene expression suggests that heat-shock genes are activated by the sequential binding of at least two protein factors...
- Nucleotide sequence analysis of the Drosophila small heat shock gene cluster at locus 67BR Southgate
J Mol Biol 165:35-57. 1983..Sequence analysis with respect to transcription initiation and termination and possible regulatory signals is discussed together with some structural predictions for the four proteins...
- Four small Drosophila heat shock proteins are related to each other and to mammalian alpha-crystallinT D Ingolia
Proc Natl Acad Sci U S A 79:2360-4. 1982..The possible functional significance of this structural similarity is discussed...
- Developmentally regulated transcription from Drosophila melanogaster chromosomal site 67BK Sirotkin
Dev Biol 89:196-210. 1982
- Patterns of puffing activity in the salivary gland chromosomes of Drosophila. V. Responses to environmental treatmentsM Ashburner
Chromosoma 31:356-76. 1970
- Primary sequence of the 5' flanking regions of the Drosophila heat shock genes in chromosome subdivision 67BT D Ingolia
Nucleic Acids Res 9:1627-42. 1981..In addition, each of the four small genes contains the sequence ACTTTNA, 195 +/- 12 bp from the proposed site of initiation of transcription...
- Four heat shock proteins of Drosophila melanogaster coded within a 12-kilobase region in chromosome subdivision 67BV Corces
Proc Natl Acad Sci U S A 77:5390-3. 1980..Including the present results, the genes for all seven major heat shock proteins of D. melanogaster are now cloned are found to exhibit a variety of patterns of organization at the five loci they occupy...
- The induction of gene activity in drosophilia by heat shockM Ashburner
Cell 17:241-54. 1979
- Identification of ecdysone response elements by analysis of the Drosophila Eip28/29 geneL Cherbas
Institute for Molecular and Cellular Biology, Indiana University, Bloomington 47405
Genes Dev 5:120-31. 1991..We have also demonstrated that an EcRE-containing region from hsp27 contains a receptor-binding site...
- A DNA segment isolated from chromosomal site 67B in D. melanogaster contains four closely linked heat-shock genesR Voellmy
Cell 23:261-70. 1981..0-4.7 kb. Three of the genes were found to exhibit alternating polarities. Thus in spite of their close linkage, the four heat-induced genes are most likely organized in individual transcription units...
- A Drosophila heat shock gene from locus 67B is expressed during embryogenesis and pupationD Pauli
Department of Molecular Biology, University of Geneva, Switzerland
J Mol Biol 198:235-40. 1987..In gene 3, this homology is restricted to the first 50 residues along the conserved 83 amino acid stretch. Two heat shock regulatory elements are localized upstream from the gene...
- Stage-specific localization of the small heat shock protein Hsp27 during oogenesis in Drosophila melanogasterR Marin
Centre de Recherches du CHUL and Laboratoire de génétique cellulaire et développementale, RSVS, Pavillon C E Marchand, Universite Laval, Ste Foy, Quebec, Canada G1K 7P4
Chromosoma 105:142-9. 1996The developmental and heat shock-induced expression of the small heat shock protein Hsp27 was investigated by confocal microscopy of whole-mount immunostained preparations of ovarioles during oogenesis in Drosophila melanogaster...
- Genetic variation in the expression of the six hsp genes in the presence of heat shock in Drosophila melanogasterY Otsuka
Division of Medical Zoology, Oita Medical University, Japan
Genes Genet Syst 72:19-24. 1997Genetic variation in total mRNA level of the six hsp genes (hsp22, hsp23, hsp26, hsp27, hsp70 and hsp82) in the presence of heat shock was investigated by using seventy-four second- and seventy third-chromosome lines of Drosophila ..