The polysaccharide chitin is a major scaffolding molecule in the insect cuticle.In order to be functional,both chitin amounts and chitin organization have been shown to be important parameters.Despite great advances i...The polysaccharide chitin is a major scaffolding molecule in the insect cuticle.In order to be functional,both chitin amounts and chitin organization have been shown to be important parameters.Despite great advances in the past decade,the molecular mechanisms of chitin synthesis and organization are not fully understood.Here,we have characterized the function of the Chitinase 6(Cht6)in the formation of the wing,which is a simple flat cuticle organ,in the fruit fly Drosophila melanogaster.Reduction of Cht6 function by RNA interference during wing development does not affect chitin organization,but entails a thinner cuticle suggesting reduced chitin amounts.This phenotype is opposed to the one reported recently to be caused by reduction of Cht10 expression.Probably as a consequence,cuticle permeability to xenobiotics is enhanced in Cht6-less wings.We also observed massive deformation of these wings.In addition,the shape of the abdomen is markedly changed upon abdominal suppression of Cht6.Finally,we found that suppression of Cht6 transcript levels influences the expression of genes coding for enzymes of the chitin biosynthesis pathway.This finding indicates that wing epidermal cells respond to activity changes of Cht6 probably trying to adjust chitin amounts.Together,in a working model,we propose that Cht6-introduced modifications of chitin are needed for chitin synthesis to proceed correctly.Cuticle thickness,according to our hypothesis,is in turn required for correct organ or body part shape.The molecular mechanisms of this processes shall be characterized in the future.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32170505,32170526)the NSFC-DFG(Grant No.31761133021)+2 种基金Natural Science Foundation of Shanxi Province(Grant No.20210302123473)Research Project Supported by Shanxi Scholarship Council of China(HGKY2019011)the Fund for Shanxi“1331 Project.”BM’s contribution was supported by the German Research Foundation(DFG grant MO1714/10-1).
文摘The polysaccharide chitin is a major scaffolding molecule in the insect cuticle.In order to be functional,both chitin amounts and chitin organization have been shown to be important parameters.Despite great advances in the past decade,the molecular mechanisms of chitin synthesis and organization are not fully understood.Here,we have characterized the function of the Chitinase 6(Cht6)in the formation of the wing,which is a simple flat cuticle organ,in the fruit fly Drosophila melanogaster.Reduction of Cht6 function by RNA interference during wing development does not affect chitin organization,but entails a thinner cuticle suggesting reduced chitin amounts.This phenotype is opposed to the one reported recently to be caused by reduction of Cht10 expression.Probably as a consequence,cuticle permeability to xenobiotics is enhanced in Cht6-less wings.We also observed massive deformation of these wings.In addition,the shape of the abdomen is markedly changed upon abdominal suppression of Cht6.Finally,we found that suppression of Cht6 transcript levels influences the expression of genes coding for enzymes of the chitin biosynthesis pathway.This finding indicates that wing epidermal cells respond to activity changes of Cht6 probably trying to adjust chitin amounts.Together,in a working model,we propose that Cht6-introduced modifications of chitin are needed for chitin synthesis to proceed correctly.Cuticle thickness,according to our hypothesis,is in turn required for correct organ or body part shape.The molecular mechanisms of this processes shall be characterized in the future.
