Expression Characteristics of AaHsp90 Gene in Antheraea assamensis under Different Temperature and Starvation Stress

[Objectives]To investigate the effects of different temperature and starvation stress on the expression of AaHsp90 and reveal the molecular mechanism of adaptation to environment in Antheraea assama.[Methods]Taking the normal feeding group at 26℃as the control,the expression change of AaHsp90 was detected by real-time PCR in midgut,fat body and hemlymph after high temperature stress at 38℃,low temperature stress at 4℃and starvation stress separately for different time on the third day of the fifth larvae.[Results]The expression of AaHsp90 in midgut,fat body and hemlymph of Antheraea assama were increased obviously at first and then decreased sharply with the prolongation of treatment time at 38℃.There has a certain inhibitory effect on the expression of AaHsp90 in midgut,fat body and hemolymph after treatment with 4℃for different time.After treatment with starvation,the AaHsp90 expression were increased at 12 and 18 h and decreased sharply at 24 h in midgut,fat body and hemolymph of A.assama.[Conclusions]Comprehensive analysis showed that high temperature and starvation stress can induce the expression of AaHsp90,while low temperature stress mainly suppressed its expression.It was suggested that the AaHsp90 protein may play an important role in the process of adaptation to high temperature and starvation stress in A.assama.

Expression Profiles and Response to Exogenous Hormones of β-Fructofuranosidase Gene BmSuc1 in Silkworms(Bombyx mori)

[Objectives]In order to clarify the regulatory effects of insect hormones on the expression of BmSuc1 and provide a reference for further analysis of the function and expression regulation mechanism of BmSuc1,this study explored the expression profiles of BmSuc1 in different tissues and periods of silkworm larvae and the expression changes of BmSuc1 after treatment with exogenous hormones.[Methods]By using the real-time fluorescence quantitative PCR technique,the expression characteristics of BmSuc1 were detected in different periods,different tissues and after treatment with exogenous hormones during the development of silkworm larvae.The expression of BmSuc1 and 20E receptor gene USP was detected after RNA interference with double-stranded RNA(dsRNA)of USP.[Results]The relative expression of BmSuc1 gene in the midgut was the highest,followed by the silk glands,epidermis and hemolymph.However,there was much lower or almost no expression in other tissues.In addition,the BmSuc1 expression profile exhibited a pulse-like pattern in silkworm larvae.The expression level of BmSuc1 was higher at each instar stage before molting,late fifth instar before cocooning and prepupal stage.Silkworm larvae at day 2 of the fifth instar were treated with 20-hydroxyecdysone(20E)and juvenile hormone(JH).It was found that the expression of BmSuc1 was extremely significantly higher at 12 and 18 h after 20E treatment than the control group injected with 0.1%dimethyl sulfoxide(DMSO)(P<0.01,the same below).But there were no significant difference in BmSuc1 expression between the JH treatment and the control group during the measurement time range(P>0.05).The dsRNA of USP was synthesized in vitro and injected into silkworm larvae at day 3 of the fifth instar.It was showed that the USP relative expression was extremely significantly down-regulated at 24 and 36 h after injection,which indicated that dsRNA interference was successful.RNAi of USP would block 20E signal transduction,and the expression of BmSuc1 was inhibited and significantly down-regulated at 24 and 36 h after injection of dsRNA of USP(P<0.05).[Conclusions]The BmSuc1 expression peaks appeared in the molting of silkworm larvae and the metamorphosis of larvae to pupae,which suggests that BmSuc1 may be involved in the metamorphic development process of silkworms.Treatment with exogenous ecdysone 20E can activate the expression of BmSuc1,but blocking the 20E signal transduction pathway may suppress expression of BmSuc1.It indicates that BmSuc1 as a downstream target gene in the 20E signal transduction pathway is directly or indirectly regulated by 20E signals.

Wavelet Analysis of Bitcoin Price and Twitter-Based Economic Uncertainty Index

In this paper,we analyze the time-series graphs of Bitcoin price and Twitter-based economic uncertainty index over the past two years and use a wavelet coherence graph to determine their relationship.We found a causal relationship between Bitcoin(BTC)and Twitter-based economic uncertainty(TEU)index in different frequency bands,which would help predict Bitcoin price movements in the future.Our study provides reference to academics and investors.

E93 promotes transcription of RHG genes to initiate apoptosis during Drosophila salivary gland metamorphosis

20-hydroxyecdysone(20E)induced transcription factor E93 is important for larval–adult transition,which functions in programmed cell death of larval obsolete tissues,and the formation of adult new tissues.However,the apoptosis-related genes directly regulated by E93 are still ambiguous.In this study,an E93 mutation fly strain was obtained by clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-mediated long exon deletion to investigate whether and how E93 induces apoptosis during larval tissues metamorphosis.The transcriptional profile of E93 was consistent with 3 RHG(rpr,hid,and grim)genes and the effector caspase gene drice,and all their expressions peaked at the initiation of apoptosis during the degradation of salivary glands.The transcription expression of 3 RHG genes decreased and apoptosis was blocked in E93 mutation salivary gland during metamorphosis.In contrast,E93 overexpression promoted the transcription of 3 RHG genes,and induced advanced apoptosis in the salivary gland.Moreover,E93 not only enhance the promoter activities of the 3 RHG genes in Drosophila Kc cells in vitro,but also in the salivary gland in vivo.Our results demonstrated that 20E induced E93 promotes the transcription of RHG genes to trigger apoptosis during obsolete tissues degradation at metamorphosis in Drosophila.