start-ver=1.4
cd-journal=joma
no-vol=6
cd-vols=
no-issue=4
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2011
dt-pub=20110425
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Environmental Stress-Dependent Effects of Deletions Encompassing Hsp70Ba on Canalization and Quantitative Trait Asymmetry in Drosophila melanogaster
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Hsp70 genes may influence the expression of wing abnormalities in Drosophila melanogaster but their effects on variability in quantitative characters and developmental instability are unclear. In this study, we focused on one of the six Hsp70 genes, Hsp70Ba, and investigated its effects on within-and among-individual variability in orbital bristle number, sternopleural bristle number, wing size and wing shape under different environmental conditions. To do this, we studied a newly constructed deletion, Df(3R)ED5579, which encompasses Hsp70Ba and nine non-Hsp genes, in the heterozygous condition and another, Hsp70Ba(304), which deletes only Hsp70Ba, in the homozygous condition. We found no significant effect of both deletions on within-individual variation quantified by fluctuating asymmetry (FA) of morphological traits. On the other hand, the Hsp70Ba(304)/Hsp70Ba(304) genotype significantly increased among-individual variation quantified by coefficient of variation (CV) of bristle number and wing size in female, while the Df(3R)ED5579 heterozygote showed no significant effect. The expression level of Hsp70Ba in the deletion heterozygote was 6 to 20 times higher than in control homozygotes, suggesting that the overexpression of Hsp70Ba did not influence developmental stability or canalization significantly. These findings suggest that the absence of expression of Hsp70Ba increases CV of some morphological traits and that HSP70Ba may buffer against environmental perturbations on some quantitative traits.
en-copyright=
kn-copyright=

en-aut-name=TakahashiKazuo H.
en-aut-sei=Takahashi
en-aut-mei=Kazuo H.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=DabornPhillip J.
en-aut-sei=Daborn
en-aut-mei=Phillip J.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=HoffmannAry A.
en-aut-sei=Hoffmann
en-aut-mei=Ary A.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=Takano-ShimizuToshiyuki
en-aut-sei=Takano-Shimizu
en-aut-mei=Toshiyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

affil-num=1
en-affil=
kn-affil=Department of Population Genetics, National Institute of Genetics

affil-num=2
en-affil=
kn-affil=Centre for Environmental Stress and Adaptation Research and Department of Genetics, The University of Melbourne

affil-num=3
en-affil=
kn-affil=Centre for Environmental Stress and Adaptation Research and Department of Genetics, The University of Melbourne

affil-num=4
en-affil=
kn-affil=Department of Population Genetics, National Institute of Genetics
END

start-ver=1.4
cd-journal=joma
no-vol=12
cd-vols=
no-issue=
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2011
dt-pub=20110622
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Genome-wide deficiency screen for the genomic regions responsible for heat resistance in Drosophila melanogaster
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Background: Temperature adaptation is one of the most important determinants of distribution and population size of organisms in nature. Recently, quantitative trait loci (QTL) mapping and gene expression profiling approaches have been used for detecting candidate genes for heat resistance. However, the resolution of QTL mapping is not high enough to examine the individual effects of various genes in each QTL. Heat stress-responsive genes, characterized by gene expression profiling studies, are not necessarily responsible for heat resistance. Some of these genes may be regulated in association with the heat stress response of other genes. 

Results: To evaluate which heat-responsive genes are potential candidates for heat resistance with higher resolution than previous QTL mapping studies, we performed genome-wide deficiency screen for QTL for heat resistance. We screened 439 isogenic deficiency strains from the DrosDel project, covering 65.6% of the Drosophila melanogaster genome in order to map QTL for thermal resistance. As a result, we found 19 QTL for heat resistance, including 3 novel QTL outside the QTL found in previous studies. 

Conclusion: The QTL found in this study encompassed 19 heat-responsive genes found in the previous gene expression profiling studies, suggesting that they were strong candidates for heat resistance. This result provides new insights into the genetic architecture of heat resistance. It also emphasizes the advantages of genome-wide deficiency screen using isogenic deficiency libraries.
en-copyright=
kn-copyright=

en-aut-name=TakahashiKazuo H.
en-aut-sei=Takahashi
en-aut-mei=Kazuo H.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=OkadaYasukazu
en-aut-sei=Okada
en-aut-mei=Yasukazu
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=TeramuraKouhei
en-aut-sei=Teramura
en-aut-mei=Kouhei
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

affil-num=1
en-affil=
kn-affil=Research Core for Interdisciplinary Sciences, Okayama University

affil-num=2
en-affil=
kn-affil=Graduate School of Environmental Science, Okayama University

affil-num=3
en-affil=
kn-affil=Graduate School of Environmental Science, Okayama University
END

start-ver=1.4
cd-journal=joma
no-vol=10
cd-vols=
no-issue=
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2010
dt-pub=20100916
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Effects of small Hsp genes on developmental stability and microenvironmental canalization
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Background:
Progression of development has to be insulated from the damaging impacts of environmental and genetic perturbations to produce highly predictable phenotypes. Molecular chaperones, such as the heat shock proteins (HSPs), are known to buffer various environmental stresses, and are deeply involved in protein homeostasis. These characteristics of HSPs imply that they might affect developmental buffering and canalization.

Results:
We examined the role of nine Hsp genes using the GAL4/UAS-RNAi system on phenotypic variation of various morphological traits in Drosophila melanogaster. The stability of bristle number, wing size and wing shape was characterized through fluctuating asymmetry (FA) and the coefficient of variation (CV), or among-individual variation. Progeny of the GAL4/Hsp-RNAi crosses tended to have reduced trait means for both wing size and wing shape. Transcriptional knockdown of Hsp67Bc and Hsp22 significantly increased FA of bristle number, while knockdown of Hsp67Ba significantly increased FA and among-individual variation of wing shape but only in males. Suppression of Hsp67Bb expression significantly increased among-individual variation of bristle number. The knockdown of gene expression was confirmed for Hsp67Ba, Hsp67Bc, Hsp22, and Hsp67Bb. Correlation between FA and CV or among-individual variation of each trait is weak and not significant except for the case of male wing shape.

Conclusion:
Four small Hsp genes (Hsp22, Hsp67Ba, Hsp67Bb and Hsp67Bc) showed involvement in the processes of morphogenesis and developmental stability. Due to possible different functions in terms of developmental buffering of these small Hsps, phenotypic stability of an organism is probably maintained by multiple mechanisms triggered by different environmental and genetic stresses on different traits. This novel finding may lead to a better understanding of non-Hsp90 molecular mechanisms controlling variability in morphological traits.
en-copyright=
kn-copyright=

en-aut-name=TakahashiKazuo H.
en-aut-sei=Takahashi
en-aut-mei=Kazuo H.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=RakoLea
en-aut-sei=Rako
en-aut-mei=Lea
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=Takano-ShimizuToshiyuki
en-aut-sei=Takano-Shimizu
en-aut-mei=Toshiyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=HoffmannAry A.
en-aut-sei=Hoffmann
en-aut-mei=Ary A.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=LeeSiu F.
en-aut-sei=Lee
en-aut-mei=Siu F.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

affil-num=1
en-affil=
kn-affil=Research Core for Interdisciplinary Sciences, Okayama University

affil-num=2
en-affil=
kn-affil=Centre for Environmental Stress and Adaptation Research, Department of Genetics, Bio21 Institute, The University of Melbourne

affil-num=3
en-affil=
kn-affil=Department of Population Genetics, National Institute of Genetics

affil-num=4
en-affil=
kn-affil=Centre for Environmental Stress and Adaptation Research, Department of Genetics, Bio21 Institute, The University of Melbourne

affil-num=5
en-affil=
kn-affil=Centre for Environmental Stress and Adaptation Research, Department of Genetics, Bio21 Institute, The University of Melbourne
END

start-ver=1.4
cd-journal=joma
no-vol=102
cd-vols=
no-issue=4
article-no=
start-page=448
end-page=457
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2011
dt-pub=201108
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Genome-wide deficiency mapping of the regions responsible for temporal canalization of the developmental processes of Drosophila melanogaster
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Developmental processes of organisms are programed to proceed in a finely regulated manner and finish within a certain period of time depending on the ambient environmental conditions. Therefore, variation in the developmental period under controlled genetic and environmental conditions indicates innate instability of the developmental process. In this study, we aimed to determine whether a molecular machinery exists that regulates the canalization of the developmental period and, if so, to test whether the same mechanism also stabilizes a morphological trait. To search for regions that influence the instability of the developmental period, we conducted genome-wide deficiency mapping with 441 isogenic deficiency strains covering 65.5% of the Drosophila melanogaster genome. We found that 11 independent deficiencies significantly increased the instability of the developmental period and 5 of these also significantly increased the fluctuating asymmetry of wing shape although there was no significant correlation between the instabilities of developmental period and wing shape in general. These results suggest that canalization processes of the developmental period and morphological traits are at least partially independent. Our findings emphasize the potential importance of temporal variation in development as an indicator of developmental stability and canalization and provide a novel perspective for understanding the regulation of phenotypic variability.
en-copyright=
kn-copyright=

en-aut-name=TakahashiKazuo H.
en-aut-sei=Takahashi
en-aut-mei=Kazuo H.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=OkadaYasukazu
en-aut-sei=Okada
en-aut-mei=Yasukazu
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=TeramuraKouhei
en-aut-sei=Teramura
en-aut-mei=Kouhei
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

affil-num=1
en-affil=
kn-affil=Research Core for Interdisciplinary Sciences, Okayama University

affil-num=2
en-affil=
kn-affil=Graduate School of Environmental Science, Okayama University

affil-num=3
en-affil=
kn-affil=Graduate School of Environmental Science, Okayama University
en-keyword=developmental period
kn-keyword=developmental period
en-keyword=developmental stability
kn-keyword=developmental stability
en-keyword=Drosophila melanogaster
kn-keyword=Drosophila melanogaster
en-keyword=wing shape
kn-keyword=wing shape
END

start-ver=1.4
cd-journal=joma
no-vol=27
cd-vols=
no-issue=1
article-no=
start-page=133
end-page=143
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2012
dt-pub=20120101
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Natural genetic variation in fluctuating asymmetry of wing shape in Drosophila melanogaster
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Fluctuating asymmetry (FA), defined as random deviation from perfect symmetry, has been used to assay the inability of individuals to buffer their developmental processes from environmental perturbations (i.e., developmental instability). In this study, we aimed to characterize the natural genetic variation in FA of wing shape in Drosophila melanogaster, collected from across the Japanese archipelago. We quantified wing shapes at whole wing and partial wing component levels and evaluated their mean and FA. We also estimated the heritability of the mean and FA of these traits. We found significant natural genetic variation in all the mean wing traits and in FA of one of the partial wing components. Heritability estimates for mean wing shapes were significant in two and four out of five wing traits in males and females, respectively. On the contrary, heritability estimates for FA were low and not significant. This is a novel study of natural genetic variation in FA of wing shape. Our findings suggest that partial wing components behave as distinct units of selection for FA, and local adaptation of the mechanisms to stabilize developmental processes occur in nature.
en-copyright=
kn-copyright=

en-aut-name=TsujinoMasahiro
en-aut-sei=Tsujino
en-aut-mei=Masahiro
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=TakahashiKazuo H.
en-aut-sei=Takahashi
en-aut-mei=Kazuo H.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

affil-num=1
en-affil=
kn-affil=Research Core for Interdisciplinary Sciences, Okayama University

affil-num=2
en-affil=
kn-affil=Research Core for Interdisciplinary Sciences, Okayama University
en-keyword=Animal model
kn-keyword=Animal model
en-keyword=Geometric morphometrics
kn-keyword=Geometric morphometrics
en-keyword=Heritability
kn-keyword=Heritability
en-keyword=Natural genetic variation
kn-keyword=Natural genetic variation
en-keyword=Wing shape
kn-keyword=Wing shape
END