摘要：
<jats:title>Abstract</jats:title><jats:p>Mermithid nematodes, such as <jats:italic>Ovomermis sinensis</jats:italic>, are used as biological control agents against many insect pests, including cotton bollworm (<jats:italic>Helicoverpa armigera</jats:italic>). However, given the host's robust immune system, the infection rate of <jats:italic>O</jats:italic>. <jats:italic>sinensis</jats:italic> is low, thus restricting its widespread use. To understand the host defense mechanisms against mermithid nematodes, we identified and characterized a protein involved in the recognition of <jats:italic>O</jats:italic>. <jats:italic>sinensis</jats:italic>, the potential <jats:italic>O</jats:italic>. <jats:italic>sinensis</jats:italic>‐binding protein C‐type lectin 1 (HaCTL1a and/or HaCTL1b), which was eluted from the surface of <jats:italic>O. sinensis</jats:italic> after incubation with <jats:italic>H</jats:italic>. <jats:italic>armigera</jats:italic> plasma. HaCTL1b is homologous to the previously reported HaCTL1a protein. HaCTL1 was predominantly expressed in hemocytes and was induced by the steroid hormone 20‐hydroxyecdysone through ecdysone receptor (HaEcR) or ultraspiracle (HaUSP), or both. Binding assays confirmed the interactions of the HaCTL1 proteins with <jats:italic>O</jats:italic>. <jats:italic>sinensis</jats:italic> but not with <jats:italic>Romanomermis wuchangensis</jats:italic>, a parasitic nematode of mosquito. Moreover, the HaCTL1 proteins were secreted into the hemocoel and promoted hemocyte‐mediated encapsulation and phagocytosis. A knockdown of HaEcR and/or HaUSP resulted in compromised encapsulation and phagocytosis. Thus, HaCTL1 appears to modulate cellular immunity in the defense against parasitic nematodes, and the 20‐hydroxyecdysone–HaEcR–HaUSP complex is involved in regulating the process.</jats:p>
摘要：
<jats:title>Abstract</jats:title><jats:p>Many ribosomal proteins (RPs) not only play essential roles in ribosome biogenesis, but also have “extraribosomal” functions in various cellular processes. <jats:italic>RpL36</jats:italic> encodes ribosomal protein L36, a component of the 60S subunit of ribosomes in <jats:italic>Drosophila melanogaster</jats:italic>. We report here that <jats:italic>RpL36</jats:italic> is required for spermatogenesis in <jats:italic>D. melanogaster</jats:italic>. After showing the evolutionary conservation of RpL36 sequences in animals, we revealed that the <jats:italic>RpL36</jats:italic> expression level in fly testes was significantly higher than in ovaries. Knockdown <jats:italic>RpL36</jats:italic> in fly testes resulted in a significantly decreased egg hatch rate when these males mated with wild‐type females. Furthermore, 76.67% of the <jats:italic>RpL36</jats:italic> knockdown fly testes were much smaller in comparison to controls. Immunofluorescence staining exhibited that in the <jats:italic>RpL36</jats:italic> knockdown testis hub cell cluster was enlarged, while the number of germ cells, including germ stem cells, was reduced. Knockdown of <jats:italic>RpL36</jats:italic> in fly testis caused much fewer or no mature sperms in seminal vesicles. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) signal was stronger in <jats:italic>RpL36</jats:italic> knockdown fly testes than in the control testes, but the TUNEL‐positive cells could not be stained by Vasa antibody, indicating that apoptotic cells are not germ cells. The percentage of pH3‐positive cells among the Vasa‐positive cells was significantly reduced. The expression of genes involved in cell death, cell cycle progression, and JAK/STAT signaling pathway was significantly changed by <jats:italic>RpL36</jats:italic> knockdown in fly testes. These results suggest that <jats:italic>RpL36</jats:italic> plays an important role in spermatogenesis, likely through JAK/STAT pathway, thus resulting in defects in cell‐cycle progression and cell death in <jats:italic>D. melanogaster</jats:italic> testes.</jats:p>
摘要：
Wolbachia are Gram-negative endosymbionts that are known to cause embryonic lethality when infected male insects mate with uninfected females or with females carrying a different strain of Wolbachia, a situation characterized as cytoplasmic incompatibility (CI). However, the mechanism of CI is not yet fully understood, although recent studies on Drosophila melanogaster have achieved great progress. Here, we found that Wolbachia infection caused changes in the expressions of several immunity-related genes, including significant upregulation of kenny (key), in the testes of D. melanogaster. Overexpression of key in fly testes led to a significant decrease in egg hatch rates when these flies mate with wild-type females. Wolbachia-infected females could rescue this embryonic lethality. Furthermore, in key overexpressing testes terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling signal was significantly stronger than in the control testes, and the level of reactive oxygen species was significantly increased. Overexpression of key also resulted in alterations of some other immunity-related gene expressions, including the downregulation of Zn72D. Knockdown of Zn72D in fly testes also led to a significant decrease in egg hatch rates. These results suggest that Wolbachia might induce the defect in male host fertility by immunity-related pathways and thus cause an oxidative damage and cell death in male testes.
作者机构：
[Bi, Jie; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan, Hubei, Peoples R China.;[Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Wang, Yu-Feng] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
关键词：
aggression;insect hosts;learning and memory capacity;mating;sleep;Wolbachia
摘要：
As one of the most successful intracellular symbiotic bacteria, Wolbachia can infect many arthropods and nematodes. Wolbachia infection usually affects the reproduction of their hosts to promote their own proliferation and transmission. Currently, most of the studies focus on the mechanisms of Wolbachia interactions with host reproduction. However, in addition to distribution in the reproductive tissues, Wolbachia also infect various somatic tissues of their hosts, including the brain. This raises the potential that Wolbachia may influence some somatic processes, such as behaviors in their hosts. So far, information about the effects of Wolbachia infection on host behavior is still very limited. The present review presents the current literature on different aspects of the influence of Wolbachia on various behaviors, including sleep, learning and memory, mating, feeding and aggression in their insect hosts. We then highlight ongoing scientific efforts in the field that need addressing to advance this field, which can have significant implications for further developing Wolbachia as environmentally friendly biocontrol agents to control insect-borne diseases and agricultural pests.
摘要：
The red swamp crayfish Procambarus clarkii is a commercially important aquaculture species in inland China. Currently, the major constraint on the crayfish industry is the shortage of high-quality juveniles. Understanding the mechanisms that regulate ovarian development and maturation in female P. clarkii is crucial for the resolution of this problem. Through RNA-Seq technology, we first obtained the deep-coverage transcriptome sequencing data from the ovary of P. clarkii. A total of 31, 080, 133 clean reads were retrieved after removing the adapters in reads and filtering out low-quality data. All reads were assembled into 69, 261 unigenes with N50 of 1, 129 bp, of which 24, 014 unigenes matched sequences in the GenBank non-redundant database. From this transcriptome data, we obtained the full-length of one fragment that was previously identified to be differently expressed between precocious and normally grown P. clarkii ovaries. This gene encodes a peptide which shared the highest identity with RDH11 from other species, thus it was named PcRDH11 (P. clarkii retinol dehydrogenase 11). qRT-PCR analysis showed that PcRDH11 was highly transcribed in the ovary at the late vitellogenic stage. In situ hybridization exhibited specific expression of PcRDH11 in follicular cells around the early oocytes, but in the late vitellogenic stage, it moved to the ooplasm. Knockdown of PcRDH11 by injection of double-stranded RNA (dsRNA) resulted in decreased transcription of vitellogenin (Vg) and vitellogenin receptor (VgR). Treatment of early embryos with dsPcRDH11 caused arrest of the embryonic development and death of embryos. These results suggest that PcRDH11 may play an important role in ovarian development and embryogenesis. Our data provide insights into the molecular regulatory mechanisms of ovarian development in P. clarkii and other crustaceans, and will be helpful for the development of new techniques for artificial regulation of the reproductive process in crayfish aquaculture.
摘要：
Cytoplasmic incompatibility (CI) is the most common phenotype induced by endosymbiont Wolbachia and results in embryonic lethality when Wolbachia-modified sperm fertilize eggs without Wolbachia. However, eggs carrying the same strain of Wolbachia can rescue this embryonic death, thus producing viable Wolbachia-infected offspring. Hence Wolbachia can be transmitted mainly by hosts’ eggs. One of the models explaining CI is “titration-restitution”, which hypothesized that Wolbachia titrated-out some factors from the sperm and the Wolbachia in the egg would restitute the factors after fertilization. However, how infected eggs rescue CI and how hosts’ eggs ensure the proliferation and transmission of Wolbachia are not well understood. By RNA-seq analyses, we first compared the transcription profiles of Drosophila melanogaster adult ovaries with and without the wMel Wolbachia and identified 149 differentially expressed genes (DEGs), of which 116 genes were upregulated and 33 were downregulated by Wolbachia infection. To confirm the results obtained from RNA-seq and to screen genes potentially associated with reproduction, 15 DEGs were selected for quantitative RT-PCR (qRT-PCR). Thirteen genes showed the same changing trend as RNA-seq analyses. To test whether these genes are associated with CI, we also detected their expression levels in testes. Nine of them exhibited different changing trends in testes from those in ovaries. To investigate how these DEGs were regulated, sRNA sequencing was performed and identified seven microRNAs (miRNAs) that were all upregulated in fly ovaries by Wolbachia infection. Matching of miRNA and mRNA data showed that these seven miRNAs regulated 15 DEGs. Wolbachia-responsive genes in fly ovaries were involved in biological processes including metabolism, transportation, oxidation-reduction, immunity, and development. Comparisons of mRNA and miRNA data from fly ovaries revealed 149 mRNAs and seven miRNAs that exhibit significant changes in expression due to Wolbachia infection. Notably, most of the DEGs showed variation in opposite directions in ovaries versus testes in the presence of Wolbachia, which generally supports the “titration-restitution” model for CI. Furthermore, genes related to metabolism were upregulated, which may benefit maximum proliferation and transmission of Wolbachia. This provides new insights into the molecular mechanisms of Wolbachia-induced CI and Wolbachia dependence on host ovaries.
作者：
Bi, Jie;Zheng, Ya;Wang, Rui-Fang;Ai, Hui;Haynes, Paula R.;...
期刊：
Insect Biochemistry and Molecular Biology,2019年106:47-54 ISSN：0965-1748
通讯作者：
Wang, Yu-Feng
作者机构：
[Yu, Xiao-Qiang; Bi, Jie; Ai, Hui; Zheng, Ya; Wang, Rui-Fang; Wang, Yu-Feng] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Haynes, Paula R.] Univ Penn, Dept Neurosci, Perelman Sch Med, Philadelphia, PA 19104 USA.;[Brownlie, Jeremy C.] Griffith Univ, Sch Nat Sci, Nathan, Qld 4111, Australia.;[Yu, Xiao-Qiang] Univ Missouri, Sch Biol Sci, Kansas City, MO 64110 USA.
通讯机构：
[Wang, Yu-Feng] C;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
关键词：
*Drosophila melanogaster;*Learning and memory capacity;*Wolbachia;*crebA;*dme-miR-92b
摘要：
Wolbachia are endosymbiotic bacteria present in a wide range of invertebrates. Although their dramatic effects on host reproductive biology have been well studied, little is known about the effects of Wolbachia on the learning and memory capacity (LMC) of hosts, despite their distribution in the host nervous system, including brain. In this study, we found that Wolbachia infection significantly enhanced LMC in both Drosophila melanogaster and D. simulans. Expression of LMC-related genes was significantly increased in the head of D. melanogaster infected with the wMel strain, and among these genes, crebA was up-regulated the most. Knockdown of crebA in Wolbachia-infected flies significantly decreased LMC, while overexpression of crebA in Wolbachia-free flies significantly enhanced the LMC of flies. More importantly, a microRNA (miRNA), dme-miR-92b, was identified to be complementary to the 3'UTR of crebA. Wolbachia infection was correlated with reduced expression of dme-miR-92b in D. melanogaster, and dme-miR-92b negatively regulated crebA through binding to its 3'UTR region. Overexpression of dme-miR-92b in Wolbachia-infected flies by microinjection of agomirs caused a significant decrease in crebA expression and LMC, while inhibition of dme-miR-92b in Wolbachia-free flies by microinjection of antagomirs resulted in a significant increase in crebA expression and LMC. These results suggest that Wolbachia may improve LMC in Drosophila by altering host gene expression through a miRNA-target pathway. Our findings help better understand the host-endosymbiont interactions and, in particular, the impact of Wolbachia on cognitive processes in invertebrate hosts.
摘要：
An important innate immune response in Drosophila melanogaster is the production of antimicrobial peptides (AMPs). Expression of AMP genes is mediated by the Toll and immune deficiency (IMD) pathways via NF-kappaB transcription factors Dorsal, DIF and Relish. Dorsal and DIF act downstream of the Toll pathway, whereas Relish acts in the IMD pathway. Dorsal and DIF are held inactive in the cytoplasm by the IkappaB protein Cactus, while Relish contains an IkappaB-like inhibitory domain at the C-terminus. NF-kappaB factors normally form homodimers and heterodimers to regulate gene expression, but formation of heterodimers between Relish and DIF or Dorsal and the specificity and activity of the three NF-kappaB homodimers and heterodimers are not well understood. In this study, we compared the activity of Rel homology domains (RHDs) of Dorsal, DIF and Relish in activation of Drosophila AMP gene promoters, demonstrated that Relish-RHD (Rel-RHD) interacted with both Dorsal-RHD and DIF-RHD, Relish-N interacted with DIF and Dorsal, and overexpression of individual RHD and co-expression of any two RHDs activated the activity of AMP gene promoters to various levels, suggesting formation of homodimers and heterodimers among Dorsal, DIF and Relish. Rel-RHD homodimers were stronger activators than heterodimers of Rel-RHD with either DIF-RHD or Dorsal-RHD, while DIF-RHD-Dorsal-RHD heterodimers were stronger activators than either DIF-RHD or Dorsal-RHD homodimers in activation of AMP gene promoters. We also identified the nucleotides at the 6th and 8th positions of the 3' half-sites of the kappaB motifs that are important for the specificity and activity of NF-kappaB transcription factors.
摘要：
Drosophila melanogaster possesses a sophisticated and effective immune system composed of humoral and cellular immune responses, and production of antimicrobial peptides (AMPs) is an important defense mechanism. Expression of AMPs is regulated by the Toll and IMD (immune deficiency) pathways. Production of AMPs can be systemic in the fat body or a local event in the midgut and epithelium. So far, most studies focus on systemic septic infection in adult flies and little is known about AMP gene activation after ingestion of killed bacteria. In this study, we investigated activation of AMP genes in the wild-type w(1118), MyD88 and Imd mutant flies after ingestion of heat-killed Escherichia coli and Staphylococcus aureus. We showed that ingestion of E. coli activated most AMP genes, including drosomycin and diptericin, in the first to third instar larvae and pupae, while ingestion of S. aureus induced only some AMP genes in some larval stages or in pupae. In adult flies, ingestion of killed bacteria activated AMP genes differently in males and females. Interestingly, ingestion of killed E. coli and S. aureus in females conferred resistance to septic infection by both live pathogenic Enterococcus faecalis and Pseudomonas aeruginosa, and ingestion of E. coli in males conferred resistance to P. aeruginosa infection. Our results indicated that E. coli and S. aureus can activate both the Toll and IMD pathways, and systemic and local immune responses work together to provide Drosophila more effective protection against infection.
作者：
Biwot, John C.;Zhang, Hua-Bao;Chen, Meng-Yan;Wang, Yu-Feng*
期刊：
Archives of Insect Biochemistry and Physiology,2019年102(4):e21612 ISSN：0739-4462
通讯作者：
Wang, Yu-Feng
作者机构：
[Zhang, Hua-Bao; Chen, Meng-Yan; Biwot, John C.; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan, Hubei, Peoples R China.;[Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Wang, Yu-Feng] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
摘要：
Zn72D encodes the Drosophila zinc finger protein Zn72D. It was first identified to be involved in phagocytosis and indicated to have a role in immunity. Then it was demonstrated to have a function in RNA splicing and dosage compensation in Drosophila melanogaster. In this study, we discovered a new function of Zn72D in male fertility. We showed that knockdown of Zn72D in fly testes caused an extremely low egg hatch rate. Immunofluorescence staining of Zn72D knockdown testes exhibited scattered spermatid nuclei and no actin cones or individualization complexes (ICs) during spermiogenesis, whereas the early-stage germ cells and the spermatocytes were observed clearly. There were no mature sperms in the seminal vesicles of Zn72D knockdown fly testes, although a few sperms could be found close to the seminal vesicle. We further showed that many cytoskeleton-related genes were significantly downregulated in fly testes due to Zn72D knockdown. Taken together these findings suggest that Zn72D may have an important function in spermatogenesis by sustaining the cytoskeleton-based morphogenesis and individualization thus ensuring the proper formation of sperm in D. melanogaster.
期刊：
Journal of Biological Chemistry,2019年294(26):10172-10181 ISSN：0021-9258
通讯作者：
Yu, Xiao-Qiang;Strand, Michael R.
作者机构：
[He, Zhen; Yu, Xiao-Qiang; Li, Chun-Feng; Chowdhury, Munmun] Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.;[Liu, Xu-Sheng; He, Zhen; Yu, Xiao-Qiang; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Yu, Xiao-Qiang; Lu, Yuzhen] South China Normal Univ, Guangzhou Key Lab Insect Dev Regulat & Applicat R, Inst Insect Sci & Technol, Guangzhou 510631, Guangdong, Peoples R China.;[Yu, Xiao-Qiang; Lu, Yuzhen] South China Normal Univ, Sch Life Sci, Guangzhou 510631, Guangdong, Peoples R China.;[Li, Chun-Feng] Southwest Univ, State Key Lab Silkworm Genome Biol, Chongqing 400716, Peoples R China.
通讯机构：
[Yu, Xiao-Qiang; Strand, Michael R.] U;Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.;Univ Georgia, Dept Entomol, Athens, GA 30602 USA.
作者机构：
[Wang, Yufeng; Mao, Bin; Fang, Nainai; Bi, Jie; Ai, Hui; Zheng, Ya] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;[Guan, Chuxiong; Hu, Yuwei; Li, Jihu; Mao, Yongkai] Guangzhou Sugarcane Ind Res Inst, Guangdong Prov Bioengn, Guangdong Key Lab Sugarcane Improvement & Biorefi, Guangzhou 510316, Guangdong, Peoples R China.
通讯机构：
[Ai, Hui] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
摘要：
Insect pheromone-binding proteins (PBPs) have been proposed to capture and transport hydrophobic sex pheromone components emitted by con-specific insects to pheromone receptors in the hemolymph of male antennal sensilla. In this study, field trapping results indicate that a mixture of E11-16: Ald and Z11-16: Ald can effectively attract a great number of male Tryporyza intacta. Real-time PCR results suggest that the transcript levels of three TintPBP1-3 genes are mainly expressed in the adult antennae. Fluorescence competitive binding experiments show that TintPBP1-3 proteins have great binding affinities to their major sex pheromones. Moreover, TintPBPs clearly cannot bind to other four kinds of sex pheromone components released by another sugarcane borer, Chilo venosatus and Chilo infuscatellu, which have the same host plant and live in similar habitats like T. intacta. The molecular docking results demonstrate that six amino acid residues of the three TintPBPs are crucial for the specific perception of the sex pheromone components. These results will provide a foundation for the development of novel sex pheromone analogues and blocking agents for biological control of sugarcane pests, improving their efficient monitoring and integrated management strategies in the sugarcane field.
摘要：
Wolbachia are endosymbiotic bacteria present in a wide range of insects. Although their dramatic effects on host reproductive biology have been well studied, the effects of Wolbachia on sleep behavior of insect hosts are not well documented. In this study, we report that Wolbachia infection caused an increase of total sleep time in both male and female Drosophila melanogaster. The increase in sleep was associated with an increase in the number of nighttime sleep bouts or episodes, but not in sleep bout duration. Correspondingly, Wolbachia infection also reduced the arousal threshold of their fly hosts. However, neither circadian rhythm nor sleep rebound following deprivation was influenced by Wolbachia infection. Transcriptional analysis of the dopamine biosynthesis pathway revealed that two essential genes, Pale and Ddc, were significantly upregulated in Wolbachia-infected flies. Together, these results indicate that Wolbachia mediates the expression of dopamine related genes, and decreases the sleep quality of their insect hosts. Our findings help better understand the host-endosymbiont interactions and in particular the Wolbachia's impact on behaviors, and thus on ecology and evolution in insect hosts.
摘要：
Growth-blocking peptide (GBP) is an insect cytokine that stimulates plasmatocyte adhesion, thereby playing a critical role in encapsulation reaction. It has been previously demonstrated that GBP-binding protein (GBPB) is released upon oenocytoid lysis in response to GBP and is responsible for subsequent clearance of GBP from hemolymph. However, current knowledge about GBPB is limited and the mechanism by which insects increase GBPB levels to inactivate GBP remains largely unexplored. Here, we have identified one GBP precursor (HaGBP precursor) gene and two GBPB (namely HaGBPB1 and HaGBPB2) genes from the cotton bollworm. Helicoverpa armigera. The HaGBP precursor was found to be predominantly expressed in fat body, whereas HaGBPB1 and HaGBPB2 were mainly expressed in hemocytes. Immunological analyses indicated that both HaGBPB1 and HaGBPB2 are released from hemocytes into the plasma during the wandering stage. Additionally, 20-hydroxyecdysone (20E) treatment or bead challenge could promote the release of HaGBPB1 and HaGBPB2 at least partly from oenocytoids into the plasma. Furthermore, we demonstrate that the N-terminus of HaGBPB1 is responsible for binding to HaGBP and suppresses HaGBP-induced plasmatocyte spreading and encapsulation. Overall, this study helps to enrich our understanding of the molecular mechanism underlying 20E mediated regulation of plasmatocyte adhesion and encapsulation via GBP-GBPB interaction. (C) 2017 Elsevier Ltd. All rights reserved.
