Both biological and engineering approaches have contributed significantly to the recent advance in the field of mechanobiology.Collaborating with biologists,bio-engineers and materials scientists have employed the tec...Both biological and engineering approaches have contributed significantly to the recent advance in the field of mechanobiology.Collaborating with biologists,bio-engineers and materials scientists have employed the techniques stemming from the conventional semiconductor industry to rebuild cellular milieus that mimic critical aspects of in vivo conditions and elicit cell/tissue responses in vitro.Such reductionist approaches have help to unveil important mechanosensing mechanism in both cellular and tissue level,including stem cell differentiation and proliferation,tissue expansion,wound healing,and cancer metastasis.In this mini-review,we discuss various microfabrication methods that have been applied to generate specific properties and functions of designer substrates/devices,which disclose cell-microenvironment interactions and the underlying biological mechanisms.In brief,we emphasize on the studies of cell/tissue mechanical responses to substrate adhesiveness,stiffness,topography,and shear flow.Moreover,we comment on the new concepts of measurement and paradigms for investigations of biological mechanotransductions that are yet to emerge due to on-going interdisciplinary efforts in the fields of mechanobiology and microengineering.展开更多
The diet composition of the Lycian salamander Lyciasalamandra luschani basoglui across both age and sex groups was studied. Specimens were collected from a small island in the Southeast Aegean Sea. The dominant prey g...The diet composition of the Lycian salamander Lyciasalamandra luschani basoglui across both age and sex groups was studied. Specimens were collected from a small island in the Southeast Aegean Sea. The dominant prey group of juveniles consisted of Collembola, while Coleoptera dominated the diet of males and females. The number and size of prey items consumed by males and females of L. luschani basoglui were quite similar, while juveniles ate fewer items of much smaller size. The numerical abundance along with the four measures of the size of prey permitted discrimination among males, females and juveniles. Although discrimination between adults and juveniles is expected due to dissimilarity in body size, discrimination between males and females remains inexplicable despite their similarity in body size. Future studies should be focused on understanding how and why prey choice differs between sexes in L. luschani basoglui.展开更多
The existence of highly differentiated X and Y chromosomes in mammals raises the issue of X-linked gene dosage compensation between XX females and XY males to avoid what would be similar to a monosomy X in males(Veiti...The existence of highly differentiated X and Y chromosomes in mammals raises the issue of X-linked gene dosage compensation between XX females and XY males to avoid what would be similar to a monosomy X in males(Veitia et al.,2015).Inactivation of one copy of the X chromosomes in females provides a dosage-compensation mechanism equalizing the expression of X-linked genes in males and females(Ohno et al.,1959;Lyon,1961).展开更多
X chromosome inactivation is a mechanism that modulates the expression of X-linked genes in eutherian females(XX).Ohno proposed that to achieve a proper balance between X-linked and autosomal genes,those on the active...X chromosome inactivation is a mechanism that modulates the expression of X-linked genes in eutherian females(XX).Ohno proposed that to achieve a proper balance between X-linked and autosomal genes,those on the active X should also undergo a 2-fold upregula-tion.Although some support for Ohno's hypothesis has been provided through the years,recent genomic studies testing this hypoth-esis have brought contradictory results and fueled debate.Thus far,there are as many results in favor as against Ohno's hypothesis,depending on the nature of the datasets and the various assumptions and thresholds involved in the analyses.However,they have con-firmed the importance of dosage balance between X-linked and autosomal genes involved in stoichiometric relationships.These facts as well as questions and hypotheses are discussed below.展开更多
There are known cases where a cell sub-population bearing a selective advantage tends to or eventually replaces another cell subpopulation within an organism. This process is supposed to underlie the purging of the mo...There are known cases where a cell sub-population bearing a selective advantage tends to or eventually replaces another cell subpopulation within an organism. This process is supposed to underlie the purging of the most frequent mitochon-drial DNA pathogenic variant from leuko-cytes and other tissues. It is also likely to explain the normal increase of sex chromo-some aneuploidy in human leukocytes with age or under pathological conditions and the expansion of a cell subpopulation after the spontaneous in vivo reversion to normal of an inherited pathogenic variant.展开更多
Changes in membrane tension significantly affect the physiological functions of cells in various ways.However,directly measuring the spatial distribution of membrane tension remains an ongoing issue.In this study,an a...Changes in membrane tension significantly affect the physiological functions of cells in various ways.However,directly measuring the spatial distribution of membrane tension remains an ongoing issue.In this study,an algorithm is proposed to determine the membrane tension inversely by executing a particle-based method and searching for the minimum deformation energy based on the cell images and focal adhesions.A standard spreading cell model is established using 3D reconstructions with images from structured illumination microscopy as the reference cell shape.The membrane tension distribution,forces across focal adhesions,and profile of the spread cell are obtained using this method,until the cell deformation energy function optimization converges.Qualitative and quantitative comparisons with previous experimental results validated the reliability of this method.The results show that in the standard spreading cell model,the membrane tension decreases from the bottom to the top of the membrane.This method can be applied to predict the membrane tension distribution of cells freely spreading into different shapes,which could improve the quantitative analysis of cellular membrane tension in various studies for cell mechanics.展开更多
文摘Both biological and engineering approaches have contributed significantly to the recent advance in the field of mechanobiology.Collaborating with biologists,bio-engineers and materials scientists have employed the techniques stemming from the conventional semiconductor industry to rebuild cellular milieus that mimic critical aspects of in vivo conditions and elicit cell/tissue responses in vitro.Such reductionist approaches have help to unveil important mechanosensing mechanism in both cellular and tissue level,including stem cell differentiation and proliferation,tissue expansion,wound healing,and cancer metastasis.In this mini-review,we discuss various microfabrication methods that have been applied to generate specific properties and functions of designer substrates/devices,which disclose cell-microenvironment interactions and the underlying biological mechanisms.In brief,we emphasize on the studies of cell/tissue mechanical responses to substrate adhesiveness,stiffness,topography,and shear flow.Moreover,we comment on the new concepts of measurement and paradigms for investigations of biological mechanotransductions that are yet to emerge due to on-going interdisciplinary efforts in the fields of mechanobiology and microengineering.
文摘The diet composition of the Lycian salamander Lyciasalamandra luschani basoglui across both age and sex groups was studied. Specimens were collected from a small island in the Southeast Aegean Sea. The dominant prey group of juveniles consisted of Collembola, while Coleoptera dominated the diet of males and females. The number and size of prey items consumed by males and females of L. luschani basoglui were quite similar, while juveniles ate fewer items of much smaller size. The numerical abundance along with the four measures of the size of prey permitted discrimination among males, females and juveniles. Although discrimination between adults and juveniles is expected due to dissimilarity in body size, discrimination between males and females remains inexplicable despite their similarity in body size. Future studies should be focused on understanding how and why prey choice differs between sexes in L. luschani basoglui.
文摘The existence of highly differentiated X and Y chromosomes in mammals raises the issue of X-linked gene dosage compensation between XX females and XY males to avoid what would be similar to a monosomy X in males(Veitia et al.,2015).Inactivation of one copy of the X chromosomes in females provides a dosage-compensation mechanism equalizing the expression of X-linked genes in males and females(Ohno et al.,1959;Lyon,1961).
基金This work was supported by the Centre Nationalde la R echerche Scientifique(CN RS,France),Paris Diderot-Paris7 University,and the Agence Nationale de la Recherche(ANR,lceberg Project).
文摘X chromosome inactivation is a mechanism that modulates the expression of X-linked genes in eutherian females(XX).Ohno proposed that to achieve a proper balance between X-linked and autosomal genes,those on the active X should also undergo a 2-fold upregula-tion.Although some support for Ohno's hypothesis has been provided through the years,recent genomic studies testing this hypoth-esis have brought contradictory results and fueled debate.Thus far,there are as many results in favor as against Ohno's hypothesis,depending on the nature of the datasets and the various assumptions and thresholds involved in the analyses.However,they have con-firmed the importance of dosage balance between X-linked and autosomal genes involved in stoichiometric relationships.These facts as well as questions and hypotheses are discussed below.
文摘There are known cases where a cell sub-population bearing a selective advantage tends to or eventually replaces another cell subpopulation within an organism. This process is supposed to underlie the purging of the most frequent mitochon-drial DNA pathogenic variant from leuko-cytes and other tissues. It is also likely to explain the normal increase of sex chromo-some aneuploidy in human leukocytes with age or under pathological conditions and the expansion of a cell subpopulation after the spontaneous in vivo reversion to normal of an inherited pathogenic variant.
基金supported by the National Key Research and Development Program of China (Grant No. 2017YFE0117100)the National Natural Science Foundation of China (Grant Nos. 11872040, and 12072198)+1 种基金the China Scholarship Council for Joint Ph.D. Program (Grant No.201206230004)funding from the Mechanobiology Institute Seed Grant and the Ministry of Education’s Academic Research Fund Tier 1 (Grant No. R-397-000-247-112)
文摘Changes in membrane tension significantly affect the physiological functions of cells in various ways.However,directly measuring the spatial distribution of membrane tension remains an ongoing issue.In this study,an algorithm is proposed to determine the membrane tension inversely by executing a particle-based method and searching for the minimum deformation energy based on the cell images and focal adhesions.A standard spreading cell model is established using 3D reconstructions with images from structured illumination microscopy as the reference cell shape.The membrane tension distribution,forces across focal adhesions,and profile of the spread cell are obtained using this method,until the cell deformation energy function optimization converges.Qualitative and quantitative comparisons with previous experimental results validated the reliability of this method.The results show that in the standard spreading cell model,the membrane tension decreases from the bottom to the top of the membrane.This method can be applied to predict the membrane tension distribution of cells freely spreading into different shapes,which could improve the quantitative analysis of cellular membrane tension in various studies for cell mechanics.