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鞣化激素是调节昆虫表皮骨化和翅膀发育的一种神经激素,尽管已经在许多不同种昆虫上克隆了鞣化激素基因,但是关于小菜蛾Plutella xylostella鞣化激素及其基因的研究至今未见报道。本研究克隆了两个小菜蛾鞣化激素基因Pxbursα和Pxbursβ(GenBank登录号分别为KF498645和KF498646)全长cDNA,其序列长度分别为537 bp和360 bp,与已报道的其他昆虫的鞣化激素氨基酸序列一致性分别为51%~68%和37%~57%。实时定量PCR分析发现Pxbursα和Pxbursβ均在蛹期表达量高,而在幼虫期和成虫期的表达量低。以Pxbursα部分序列的双链RNA(dsRNA)饲喂小菜蛾4龄末期幼虫,发现蛹期Pxbursα的表达受到了显著抑制,小菜蛾的发育停滞在蛹期而无法正常羽化,并最终死亡。由此推测,小菜蛾鞣化激素基因在蛹期的大量表达对其生长发育和羽化具有重要的作用。
Tanning hormones are neurohormones that regulate ossification and wing development in insect epidermis. Although tanning hormone genes have been cloned on many different insects, no studies on tandem hormones and their genes in the diamondback moth Plutella xylostella have so far been found Reported. In this study, two full-length cDNAs of Pxbursα and Pxbursβ, two tandem hormone genes of Plutella xylostella, were cloned and sequenced. The full length cDNAs of Pxbursα and Pxbursβ were 537 bp and 360 bp, respectively. Compared with other reported tanning hormones The amino acid sequence identities were 51% -68% and 37% -57%, respectively. Real-time quantitative PCR analysis showed that both Pxbursαand Pxbursβwere expressed at the pupal stage but low at larval stage and adult stage. The 4th-instar larvae of Plutella xylostella were fed with double-stranded RNA (dsRNA) of partial sequence of Pxbursα, and the expression of Pxbursα was significantly inhibited at pupal stage. The development of Plutella xylostella larvae at pupal stage and eventually died. Therefore, it is speculated that the large expression of tannin in the diamondback moth during pupal stage has an important role in its growth and eclosion.