Abstract：
Nuclear receptors (NRs) are ligand-regulated transcription factors that are important for the normal growth and development of insects. However, systematic function analysis of NRs in the molting process of Lasioderma serricorne has not been reported. In this study, we identified and characterized 16 NR genes from L. serricorne. Spatiotemporal expression analysis revealed that six NRs were mainly expressed in 3-d-old 4th-instar larvae; five NRs were primarily expressed in 5-d-old adults and four NRs were predominately expressed in prepupae. All the NRs were highly expressed in epidermis, fat body and foregut. RNA interference (RNAi) experiments revealed that knockdown of 15 NRs disrupted the larva-pupa-adult transitions and caused 64.44-100 % mortality. Hematoxylin-eosin staining showed that depletion of 12 NRs prevented the formation of new cuticle and disrupted apolysis of old cuticle. Silencing of LsHR96, LsSVP and LsE78 led to newly formed cuticle that was thinner than the controls. The 20E titer and chitin content significantly decreased by 17.67-95.12 % after 15 NR dsRNA injection and the gene expression levels of 20E synthesis genes and chitin metabolism genes were significantly reduced. These results demonstrated that 15 NR genes are essential for normal molting and metamorphosis of L. serricorne by regulating 20E synthesis and chitin metabolism.
摘要：
核受体（NRs）是配体调节的转录因子，对昆虫的正常生长和发育很重要。然而,NRs在蛇皮蜕皮过程中的系统功能分析尚未见报道。在这项研究中,我们鉴定并表征了沙氏乳杆菌的16个NR基因。时空表达分析显示，6个NRs主要在3日龄4龄幼虫中表达；5个NRs主要在5日龄成虫中表达，4个NRs主要在pre中表达。所有NRs均在表皮中高表达，脂肪的身体和前肠。RNA干扰（RNAi）实验表明，15个NRs的敲低破坏了幼虫-p-成虫的转变，并导致64.44-100％的死亡率。苏木精-伊红染色显示，12个NRs的消耗阻止了新角质层的形成，并破坏了旧角质层的分解。LsHR96，LsSVP和LsE78的沉默导致新形成的角质层比对照更薄。15个NRdsRNA注射后，20E滴度和几丁质含量显着降低了17.67-95.12％，20E合成基因和几丁质代谢基因的基因表达水平显着降低。这些结果表明，15个NR基因通过调节20E的合成和几丁质代谢，对正常蜕皮和变态至关重要。
