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>
作者机构：
[Liu, Xu-Sheng; Wang, Wen-Wen; Wang, Gui-Jie; Zhuo, Xiao-Rong; Wang, Guo-Xiu; Wang, Jia-Lin] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
Ovomermis sinensis;Helicoverpa armigera;Immunity;Parasitism;Fat body
摘要：
BACKGROUND: Mermithid nematodes, such as Ovomermis sinensis, display a broad host range including some lepidopteran pests. Infective juveniles penetrate their host through the cuticle, complete their growth within the hemocoel and eventually kill the host upon their emergence. Hence, mermithid nematodes are considered potential biological control agents of insect pests. Our previous data indicate that the infection rate of O. sinensis on cotton bollworm (Helicoverpa armigera) is low, which may be largely due to the strong immune system of the host. However, current knowledge on the interactions of mermithid nematodes with their hosts and the mechanisms employed by hosts to defend themselves against mermithid nematodes is limited. RESULTS: Here, we investigated the response of H. armigera to O. sinensis infection. Parasitism by O. sinensis caused a sharp decline in the survival rate of H. armigera. The hemocytic phagocytosis ability, antibacterial activity, and phenoloxidase (PO) activity in plasma of H. armigera increased at 1 d post parasitism (dpp) but decreased at 3 dpp. Further, we investigated gene expression in the fat body of parasitized and non-parasitized H. armigera larvae at 1, 3, and 5 dpp using a digital gene expression system. In total, 41, 60 and 68 immune-related differentially expressed genes were identified at 1, 3, and 5 dpp, respectively. These genes encoded pattern recognition receptors (PRRs), antimicrobial peptides (AMPs), serine proteases (SPs), SP inhibitors, mucins and other immune-related proteins. The expression of most PRRs, AMPs, SPs, and mucins was upregulated in the fat body of larvae at 1 dpp, downregulated at 3 dpp, and then again upregulated at 5 dpp by O. sinensis. The increased expression of SP inhibitors may contribute to the inhibited PO activity at 5 dpp. CONCLUSIONS: This study demonstrates that parasitism by O. sinensis modulates the immune reaction of the host H. armigera by altering the expression of immune-related genes. Our data provide a basis for future investigation of the molecular mechanisms employed by the mermithid nematode O. sinensis to modulate the immunity of the host H. armigera. These data will also likely facilitate the improvement of success in parasitism of H. armigera by O. sinensis.
摘要：
Ovomermis sinensis is a potentially-valuable nematode for controlling insect pests. The parasitic stage of the nematode absorbs nutrients in its host’s hemolymph to maintain its growth development and then kills the host when it emerges. At present, little known about its reproductive development, particularly the responsible molecular mechanism. More detailed research on the genes of reproductive development will not only help us understand the mechanisms underlying sex differentiation in the nematode, but would also be valuable for successfully cultivating them in vitro and using them for biocontrol. In this study, we used the homology cloning method to clone the full-length cDNA of a DEAD-box family gene (Oslaf-1) from O. sinensis. Then, using qRT-PCR technology to detect the expression pattern of the Oslaf-1 gene at different development stages and tissues, the gene was found to be highly expressed in the post-parasitic stage (P < 0.01) and ovarian (P < 0.05) of O. sinensis. Western blot analysis showed the same result that the gene is associated with gonadal development and function, but is not gonad-specific. In situ hybridization further demonstrated that the gene is widely expressed in early embryos and is mainly distributed in the gonadal area. However, the signal was mainly concentrated in the reproductive primordia in pre-parasitic juveniles. RNA interference (RNAi) studies revealed that the sex ratio of O. sinensis soaked in dsRNA of Oslaf-1 was not statistically different than the gfp dsRNA treated groups. Our results suggest that Oslaf-1 may play a vital role in the reproductive systems of the nematode. In addition, we speculate that the Oslaf-1 gene plays an important role during embryonic development and that it occurs and develops in the gonads of pre-parasitic juveniles of O. sinensis.
摘要：
The encapsulation reaction in invertebrates is analogous to granuloma formation in vertebrates, and this reaction is severely compromised when ecdysone signaling is blocked. However, the molecular mechanism underlying the encapsulation reaction and its regulation by ecdysone remains obscure. In our previous study, we found that the C-type lectin HaCTL3, from the cotton bollworm Helicoverpa armigera, is involved in anti-bacterial immune response, acting as a pattern recognition receptor (PRR). In the current study, we demonstrate that HaCTL3 is involved in defense against parasites and directly binds to the surface of nematodes. Our in vitro and in vivo studies indicate that HaCTL3 enhances hemocytic encapsulation and melanization, whereas H. armigera beta-integrin (Ha beta-integrin), located on the surface of hemocytes, participates in encapsulation. Additionally, co-immunoprecipitation experiments reveal HaCTL3 interacts with Ha beta-integrin, and knockdown of Ha beta-integrin leads to reduced encapsulation of HaCTL3-coated beads. These results indicate that Ha beta-integrin serves as a hemocytic receptor of HaCTL3 during the encapsulation reaction. Furthermore, we demonstrate that 20-hydroxyecdysone (20E) treatment dramatically induces the expression of HaCTL3, and knockdown of the 20E receptor (EcR)/ultraspiracle (USP), abrogates this response. Overall, this study provides the first evidence of the presence of a hemocytic receptor (Ha beta-integrin), that interacts with the PRR HaCTL3 to facilitate encapsulation reaction in insects and demonstrates the regulation of this process by the steroid hormone ecdysone. (C) 2017 Elsevier Ltd. All rights reserved.
期刊：
Mitochondrial DNA Part A,2016年27(3):1763-1764 ISSN：2470-1394
通讯作者：
Wang, Guo-Xiu
作者机构：
[Yang, Shuang-Shuang; Li, Shan; Wang, Guo-Xiu] Cent China Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.;[Wang, Guo-Xiu] Cent China Normal Univ, Coll Life Sci, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
通讯机构：
[Wang, Guo-Xiu] C;Cent China Normal Univ, Coll Life Sci, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
关键词：
ribosome RNA;transfer RNA;animal;classification;DNA base composition;DNA sequence;gene order;genetics;mitochondrial genome;phylogeny;Rhabditida;Animals;Base Composition;Gene Order;Genome, Mitochondrial;Phylogeny;Rhabditida;RNA, Ribosomal;RNA, Transfer;Sequence Analysis, DNA
摘要：
Abstract In order to further study the characteristic of Caenorhabditis, the complete mitochondrial genome (mitogenome) of a modal nematode species Caenorhabditis tropicalis n. sp. (previous species name: C. sp. 11) was determined. The results showed that the mitogenome was 13,874 bp in length, which contained 12 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), an AT-rich region and 2 non-coding regions (NCR). The base composition of the heavy strand was 28.12% A, 47.57% T, 15.53% G, and 8.78% C. Furthermore, it is more significant that this mitogenome has two unique features: One is the AT-rich region which had 4 runs of 12 AT dinucleotides and 4 copies of directly repeated sequence (47 bp) within a pair of inverted repeat sequence (13 bp), and the other is that the NCR (130 bp) between tRNAArg and tRNAGln of 4 small stem-loop which was described at the first time. This paper firstly expounded the the complete mitogenome of C. tropicalis n. sp. So it can enrich the molecular resource and facilitate the further research of the population genetics and systematics for Caenorhabditis.
作者机构：
[Yang S.; Feng X.; Duan M.; Wang G.; Lu D.; Jiao Z.] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
通讯机构：
[Guoxiu Wang] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
摘要：
The mitochondrial genome (mitogenome) can provide information on genomic structure and can also be useful for phylogenetic analysis and evolutionary biology. A complete mitogenome sequence of a model nematode species, Caenorhabditis remanei, was determined. This mitogenome was 13,977 base pairs (bp) in length and contained 12 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA genes, and non-coding regions. The nucleotide composition of the C. remanei mitogenome (heavy strand) was heavily biased toward A and T, with the overall A + T content was 77.46%. This bias had strong effects on the codon usage and relative synonymous codon usage in the PCGs. Thus, among the 12 PCGs, ATT and TAG were the most frequently used initiation and termination codons, respectively. In C. remanei, none of the mitogenome tRNAs, consistent with findings in other nematodes, could be folded into the canonical cloverleaf secondary structure, with 20 tRNAs lacking the T Psi C (thymidine, pseudouridine, and cytidine) arm and two serine tRNAs (trnS) missing the dihydrouracil (DHU) arm. In addition to the two large non-coding region, the AT-rich region and a non-coding region located between the nad4 and cox1 genes, several small non-coding intergenic spacers(INGS) was also detected in the C. remanei mitogenome. Comparison of the C. remanei mitogenome with those of four other Caenorhabditis species showed that these mitogenomesmainly differed in their non-coding regions. Finally, phylogenetic relationships among the five Caenorhabditis species were reconstructed based on the concatenated amino acid sequences of the 12 PCGs using the maximum likelihood and Bayesian inference methods, and the results supported the morphological classification and molecular analysis data from earlier studies. (C) 2016 Elsevier Inc. All rights reserved.
摘要：
Mosquito-transmitted diseases like malaria and dengue fever are global problem and an estimated 50-100 million of dengue or dengue hemorrhagic fever cases are reported worldwide every year. The mermithid nematode Romanomermis wuchangensis has been successfully used as an ecosystem-friendly biocontrol agent for mosquito prevention in laboratory studies. However, this nematode can not undergo sex differentiation in vitro culture, which has seriously affected their application of biocontrol in the field. In this study, based on transcriptome sequencing analysis of R. wuchangensis, Rwucmab-3, Rwuclaf-1 and Rwuctra-2 were cloned and used to investigate molecular regulatory function of sex differentiation. qRT-PCR results demonstrated that the expression level of Rwucmab-3 between male and female displayed obvious difference on the 3rd day of parasitic stage, which was earlier than Rwuclaf-1 and Rwuctra-2, highlighting sex differentiation process may start on the 3rd day of parasitic stage. Besides, FITC was used as a marker to test dsRNA uptake efficiency of R. wuchangensis, which fluorescence intensity increased with FITC concentration after 16 h incubation, indicating this nematode can successfully ingest soaking solution via its cuticle. RNAi results revealed the sex ratio of R. wuchangensis from RNAi treated groups soaked in dsRNA of Rwucmab-3 was significantly higher than gfp dsRNA treated groups and control groups, highlighting RNAi of Rwumab-3 may hinder the development of male nematodes. These results suggest that Rwucmab-3 mainly involves in the initiation of sex differentiation and the development of male sexual dimorphism. Rwuclaf-1 and Rwuctra-2 may play vital role in nematode reproductive and developmental system. In conclusion, transcript sequences presented in this study could provide more bioinformatics resources for future studies on gene cloning and other molecular regulatory mechanism in R. wuchangensis. Moreover, identification and functional analysis of sex differentiation genes may clarify the sex differentiation mechanism of R. wuchangensis, which are helpful to solve the uncompleted sex differentiation problem in vitro culture and the potential large-scale field application controlling the larvae of C. quinquefasciatus, A. aegypti and A. albopictus.
摘要：
Retroposition, a molecular mechanism generating new genes, helps the formation of retrogenes and new functions, contributing to the evolution of genomes. The completed genome sequence of Caenorhabditis sp. 5 presents an excellent opportunity to identify retrogenes within C. sp. 5. We identified a total of 43 retrogenes and their corresponding chimeric genes. Among these, 29 were found to be intact retrogenes and 14 to be retropseudogenes. Unexpectedly, a high number of retrogenes appear to be functional and possibly involved in catalysis. Also, the proportion of the retrogenes forming chimeric structure is the highest among Caenorhabditis nematodes. In addition, the Ks distribution shows that C. sp. 5 has more retrogenes with high Ks, which may explain the high functionality of them among Caenorhabditis species. Our study will be helpful in the understanding of the functional and evolutionary impact of retroposition on C. sp. 5 genome.
作者：
Kun Zhou;Beibei Huang;Ming Zou;Dandan Lu;Shunping He;...
期刊：
Data in Brief,2015年4(1):595-601 ISSN：2352-3409
通讯作者：
Shunping He<&wdkj&>Guoxiu Wang
作者机构：
[Kun Zhou; Beibei Huang; Guoxiu Wang; Dandan Lu] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China;[Ming Zou] Huazhong Agriculture University, Wuhan 430070, China;[Shunping He] The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
通讯机构：
[Shunping He] T;[Guoxiu Wang] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China<&wdkj&>The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
摘要：
Chemoreception is a key feature in selection of host plant by phytophagous insects, and odorant-binding proteins (OBPs) are involved in chemical communication of both insects and vertebrates. The legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae) is one of the key pest species of cowpea and widely distributed throughout tropical and subtropical regions, causing up to 80% of yield loss. In this study, we investigated the electrophysiological responses of female M. vitrata to floral volatiles from V. unguiculata. Seventeen electroantennogram-active compounds were identified from floral volatiles of V. unguiculata by coupled gas chromatography-electroantennography (GC-EAD) and gas chromatography-mass spectrometry (GC-MS). Then, we cloned two novel full-length GOBP genes (MvitGOBP1 and MvitGOBP2) from the antennae of M. vitrata using reverse transcription PCR. Protein sequence analysis indicated that they shared high sequence similarity with other Pyralididae insect GOBPs and had the typical six-cysteine signature. Real-time PCR analysis indicated that MvitGOBP1-2 mRNA was highly expressed in the antennae of female adult with several thousands-fold difference compare to other tissue. Next, the recombinant MvitGOBP1-2 was expressed in Escherichia coli and purified using Ni ion affinity chromatography. Fluorescence binding assays demonstrated that MvitGOBP1-2 had different binding affinities with 17 volatile odorant molecules including butanoic acid butyl ester, limonene, 4-ethylpropiophenone, 1H-indol-4-ol, butanoic acid octyl ester and 2-methyl-3-phenylpropanal. In the field trapping experiment, these six floral volatiles could effectively attract female moths and showed significant difference compared with the blank lure. These results suggested that MvitGOBPs and the seventeen floral volatiles are likely to function in the olfactory behavior response of female moths, which may have played crucial roles in the selection of oviposition sites. The six compounds that we have identified from the volatiles of V. unguiculata may provide useful information for exploring efficiency monitoring and integrated pest management strategies of this legume pod borer in the field.
摘要：
With the rapid growth of sequencing technology, a number of genomes and transcriptomes of various species have been sequenced, contributing to the study of lineage-specific genes (LSGs). We identified two sets of LSGs using BLAST: one included Caenorhabditis elegans species-specific genes (1423, SSGs), and the other consisted of Caenorhabditis genus-specific genes (4539, GSGs). The subsequent characterization and analysis of the SSGs and GSGs showed that they have significant differences in evolution and that most LSGs were generated by gene duplication and integration of transposable elements (TEs). We then performed temporal expression profiling and protein function prediction and observed that many SSGs and GSGs are expressed and that genes involved with sex determination, specific stress, immune response, and morphogenesis are over-represented, suggesting that these specific genes may be related to the Caenorhabditis nematodes' special ability to survive in severe and extreme environments. (C) 2015 Elsevier Inc. All rights reserved.
作者机构：
[Zhenlong Jiao; Liuhui Chen; Guoxiu Wang] Hubei Key Laboratory of Genetic Regulation and Integrative Biology,Huazhong Normal University, Wuhan 430079, Hubei Province, China
会议名称：
The 10th Conference of Insect Physiology, Biochemistry and Molecular Biology(第四届国际昆虫生理生化与分子生物学学术研讨会暨第十届全国昆虫生理生化与分子生物学学术会议)
会议时间：
2013-6-15
会议地点：
南京
会议主办单位：
中国昆虫学会
会议论文集名称：
The 10th Conference of Insect Physiology, Biochemistry and Molecular Biology(第四届国际昆虫生理生化与分子生物学学术研讨会暨第十届全国昆虫生理生化与分子生物学学术会议)论文集
摘要：
<正>The insect-parasitic nematode,Ovomermis sinensis Chen et al.,1991 has potential for the biological control of a range of insect pests.The insect host dies when the juvenile nematode completes its parasitic development and exits
