Accumulation of a specific subset of D. melanogaster heat shock mRNAs in normal development without heat shock

During normal development in D. 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. The three mRNAs appear to originate in nurse cells and subsequently pass, during stages 10-11, into the oocyte. Little if any of the four other heat shock mRNAs is present in unshocked ovaries or embryos at any time examined. Pre-blastoderm embryos fail to accumulate these heat shock mRNAs even if subjected to heat shock. The accumulation in normal oogenesis of mRNAs for only three of the seven heat shock proteins indicates the existence of differential, possibly multiple controls of heat shock gene expression, and suggests that heat shock proteins hsp83, hsp28 and hsp26 function in the oocyte or early embryo.     

取食不同辣椒品种果实成分对棉铃虫幼虫唾腺蛋白及相应基因表达的影响

【目的】棉铃虫Helicoverpa armigera（Hübner）在不同辣椒Capsicum annuum L. 品种上的寄主适合度存在较大差异。本研究的目的是弄清不同辣椒品种对棉铃虫唾腺蛋白及相应基因表达的影响。【方法】通过双向电泳和实时荧光定量PCR（real-time quantitative PCR）的方法,探讨棉铃虫5龄幼虫取食添加辣椒碱含量不同的4个辣椒品种果实成分的人工饲料后,其唾腺中蛋白及相应基因表达的变化。【结果】双向电泳结果表明：取食4个处理的人工饲料后,棉铃虫5龄幼虫唾腺中蛋白质表达存在显著差异（P<0.05）,定量分析发现 28个蛋白点在不同处理间差异表达。通过ESI-Q-TOF-MS分析鉴定出15种差异表达蛋白,其中β-呋喃果糖苷酶（β-fructofuranosidase）、热休克蛋白70（HSP70）和翻译起始因子5A（eIF5A）在不同处理间差异较大。进一步荧光定量PCR分析显示：人工饲料中添加辣椒碱含量较高的果实成分能够促进棉铃虫β-fructofuranosidase基因的表达,添加辣椒碱含量较低的果实成分则抑制了该基因的表达;4个处理对棉铃虫hsp70基因的表达均表现出持续抑制,对eIF5A基因则均表现出一定程度的抑制。【结论】该结果为丰富和拓宽β-fructofuranosidase,hsp70 和eIF5A在昆虫中的功能研究、揭示棉铃虫对辣椒的寄主适应机制和生产上抗虫辣椒品种的选育提供了重要的基础材料。