小菜蛾热休克蛋白基因的鉴定及其表达模式分析

热休克蛋白(heat shock protein, HSP)在昆虫应对外界胁迫刺激时起着重要作用。为了系统研究小菜蛾Plutella xylostella HSP基因家族， 根据家蚕的HSP蛋白序列， 采用本地Blast程序对小菜蛾全基因组数据库进行同源序列检索， 从小菜蛾基因组数据库中鉴定了25个HSP基因， 包括2个HSP90、 8个HSP70和15个sHSP（small heat shock protein, sHSP）基因。小菜蛾、 家蚕Bombyx mori、 黑腹果蝇Drosophila melanogaster和赤拟谷盗Tribolium castaneum的HSP系统进化分析显示， 昆虫的小分子量热休克蛋白sHSP具有很强的种属特异性， HSP70家族的保守性比sHSP强。小菜蛾HSP基因表达模式分析显示， 与敏感品系对比， 抗性品系（抗毒死蜱和抗氟虫氰品系）中HSP基因具有不同的表达模式。小菜蛾1， 2和3龄幼虫HSP基因表达模式较为接近， 而与4龄幼虫中的表达模式相差较大； 4龄幼虫和蛹中的表达模式相近； 雌成虫和雄成虫中的表达模式显著不同， 与果蝇精子形成有关的两个热休克蛋白HSP23和HSP27基因［分别为CCG003980.1 (Px23.5)和CCG005412.2 (Px27.5)］， 在小菜蛾雄成虫中的表达量显著高于雌成虫。研究结果表明小菜蛾HSP基因不仅在杀虫剂抗性、 发育分化， 甚至在生殖上均可能起着重要的作用。本研究为深入研究小菜蛾HSP与生长发育、 抗逆行为的相互关系奠定了基础。

Identification and expression patterns of heat shock protein genes in the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae)

 Heat shock proteins (HSPs) play an important role in the stress stimulation of insects. In order to study the HSP gene family of Plutella xylostella, 25 HSP genes, including 2 HSP90, 8 HSP70 and 15 sHSP （small heat shock protein， sHSP） genes, were identified from the P. xylostella genome by comparison with the HSP genes from the Bombyx mori genome using local Blast program. Phylogenetic analysis of the HSP genes from the genomes of P. xylostella, B. mori, Drosophila melanogaster and Tribolium castaneum revealed that sHSPs are species-specific, but HSP70 proteins are more conserved than sHSPs in insects. The analysis of expression patterns of HSP genes from P. xylostella revealed that the insecticide resistant-strains had different expression patterns of HSP genes from the susceptible strain. The expression patterns of HSP genes among the 1st, 2nd and 3rd instar larvae were similar, but their expression patterns were different from that in the 4th instar larva. The expression patterns of HSP genes between the 4th instar larva and pupa were similar, while those between male and female adults were significantly different. The expression of two sHSP genes ［CCG003980.1 (Px23.5) and CCG005412.2 (Px27.5)］ was up-regulated significantly in male adults compared to female adults, which were identified with a function of sperm production in D. melanogaster. The results indicate that HSPs may play an important role not only in pesticide resistance, development and metamorphosis, but in reproduction in insects. This study provides a foundation for further studies on the interactions between HSPs and the development and stress resistance of P. xylostella.