伞裙追寄蝇滞育关联基因的转录组学分析

【目的】本研究旨在探讨调控伞裙追寄蝇Exorista civilis滞育的重要关联基因以及代谢途径,为明确该虫在转录组水平下的滞育分子机制提供理论基础。【方法】采用新一代高通量测序平台Illumina HiSeq^TM2000对伞裙追寄蝇非滞育以及滞育的蛹进行转录组测序分析以及生物信息学分析;应用KAAS在线pathway比对分析工具对筛选出的满足padj<0.05且fold change≥32或padj<0.05且fold change≤1/32条件的差异表达基因进行KEGG通路富集分析。【结果】根据测序结果,共获取58 050个基因。差异倍数在32倍以上的滞育关联基因(diapause-associated genes, DAGs)有454个,其中406个表达上调,共涉及134条通路,包括氧化磷酸化、柠檬酸循环及其他重要通路;48个表达下调,涉及32条通路。KEGG通路富集分析结果表明,滞育关联基因主要集中在信号转导、内分泌系统、碳水化合物代谢等途径中。【结论】本研究获得的伞裙追寄蝇转录组数据揭示了其滞育调控的重要代谢途径与关联基因。     

伞裙追寄蝇滞育关联基因和滞育关联代谢物的联合分析

为探索伞裙追寄蝇蛹滞育调控的分子机制,本文对伞裙追寄蝇Exorista civilis滞育蛹和非滞育蛹进行转录组测序以及代谢组检测,鉴定其关键的滞育关联基因(diapause-associated genes, DEGs)和滞育关联代谢物(diapasuse-associated metabolites, DEMs)。本研究基于高通量测序以及液质联用技术,通过筛选,在转录组中获得了差异表达基因7 513个,在代谢组中,获得差异代谢物501个,其中氨基酸占比最多。将所有差异表达基因与差异表达代谢物同时向KEGG映射,获得两者共同的pathway信息,明确差异表达基因与差异代谢物共同参与的主要生化途径和信号转导途径。本研究通过转录组和代谢组的联合分析,在正、负离子模式下,差异表达基因与差异代谢物共同富集到70条通路。在负离子模式下,滞育关联因子主要参与氨基酸代谢和神经系统;在正离子模式下,滞育关联因子主要参与消化系统和信号转导途径。本研究重点分析了柠檬酸循环、cAMP信号通路、氨酰-tRNA的生物合成,将为进一步深入研究伞裙追寄蝇滞育调控的分子机制奠定理论基础。     

七星瓢虫滞育关联基因的转录组学分析

对七星瓢虫正常发育、滞育以及滞育解除的雌成虫进行RNA测序,并对筛选出来的滞育相关基因进行KEGG通路富集分析,从分子水平解析七星瓢虫滞育发机理。本研究以正常发育产卵、滞育30 d以及滞育贮存30 d后解除产卵的七星瓢虫雌成虫为研究对象,分别抽提RNA,合成c DNA,构建c DNA文库,文库检测合格后在Illummina Hiseq 2500测序仪上进行双向测序。根据测序结果,共获取unigene 82820个。采用两两比较法对正常发育组和滞育组、滞育组和滞育解除组进行差异表达分析,分别获得差异表达基因3501个和1427个。深入分析两组比对结果,将在滞育组上调且滞育解除组下调的unigene定义为滞育关联基因,共有443个基因为滞育关联基因。应用KEGG KAAS在线pathway比对分析工具对滞育关联基因进行通路富集分析,结果发现这些基因主要集中在碳水化合物代谢、脂质代谢以及信号转导等途径中。     

伞裙追寄蝇和双斑截尾寄蝇对草地螟的寄生特性

为认识寄生蝇对草地螟Loxostege sticticalis L.的寄生特性,调查了河北康保田间两种寄生蝇——伞裙追寄蝇Exorista civilis Rondani和双斑截尾寄蝇Nemorilla maculosa Meigen对草地螟各龄幼虫的寄生率、寄生部位及着卵量,并通过室内饲养对寄生蝇的存活率与寄主龄期、着卵部位及着卵量的关系进行了研究。结果表明： 两种寄生蝇在田间主要寄生草地螟5龄幼虫;寄生蝇可在每头寄主幼虫上着1～8粒卵不等,其中以1粒的居多（45.3%）,2粒的次之（33.6%）,但1头寄主幼虫中仅能羽化出1头寄生蝇;寄生蝇以寄生寄主幼虫头部和胸部较多,腹部较少,并且以寄生侧面居多,背面次之,腹面最少。寄生蝇的存活与寄主幼虫着卵量之间呈相关关系,在着卵量为1粒的寄主幼虫中,寄生蝇的存活率仅为66.7%,在着卵量为2粒及以上的寄主幼虫中,单头幼虫羽化出寄生蝇的比例为100%。     

伞裙追寄蝇对不同寄主的选择性

通过实验室观察及Y型管选择性试验,对草地螟上的优势种寄蝇-伞裙追寄蝇Exorista civilis Rond.的寄主选择性进行了研究。从这6种供试寄主中筛选出优良繁蝇的替代寄主,为该蝇的大规模繁殖及应用奠定理论基础。试验结果表明:伞裙追寄蝇对6种鳞翅目幼虫和幼虫粪便的趋性顺序相同,依次为草地螟>粘虫>斜纹夜蛾>甜菜夜蛾>玉米螟>苜蓿夜蛾;不同寄主的羽化率结果表明,粘虫的羽化率最高,为70.2%。伞裙追寄蝇对寄主的选择性行为可能与寄主昆虫的活跃程度和其释放的化学信息物质有关。     

伞裙追寄蝇不同地理种群遗传多样性的ISSＲ分析

为从分子水平探索不同地区伞裙追寄蝇种群间的内在联系,本文利用ISSR分子标记技术对8个不同地区伞裙追寄蝇自然种群进行遗传多样性、种群间分化程度以及聚类分析等研究。结果表明:筛选出11对多态性稳定的ISSR引物,对8个地区伞裙追寄蝇群体的80个个体进行PCR扩增,共获得166个重复性好且清晰可辨的ISSR条带,平均每条引物扩增出15.0909个片段,且均为多态性条带,多态信息含量(PIC)为0.8441-0.8653;香农信息指数(I)为0.1240-0.3455;Nei's遗传多样性指数(H)为0.0841-0.2285;基因分化率(Gst)为28.78%,基因流(Nm)的均值为1.5702,即遗传变异主要存在于个体之间,不同种群间基因交流处于中等水平;8个地区伞裙追寄蝇种群被划分为4个类群,种群间的遗传分化与地理距离呈正相关关系。     

西伯利亚蝗卵发育过程的比较转录组分析及滞育关联基因筛选

【目的】通过筛选西伯利亚蝗Gomphocerus sibiricus卵滞育基因及代谢通路,初步明确西伯利亚蝗卵滞育分子机理。【方法】利用Illumina NovaSeq 6000测序平台对西伯利亚蝗早期发育(ES)、滞育(DS)和滞育后发育阶段(PS)的卵进行转录组测序;采用GO和KEGG富集分析并结合文献,预测滞育相关通路并聚类热图分析,筛选蝗卵滞育关联基因,并选取其中6个重要基因进行qRT-PCR验证。【结果】DSvs ES和PS vs DS两比较组分别富集到12 419和4 789个差异表达基因,且多上调表达;两比较组共表达差异基因为2 206个,主要与糖代谢、环境胁迫和生长发育相关。DS vs ES组富集最显著的GO条目为蛋白结合,PS vs DS组GO条目主要包含酶活性、细胞骨架构建及蛋白结合等过程。滞育关联基因主要集中在Wnt信号通路、胰岛素信号通路、细胞周期通路以及昆虫激素生物合成等通路。6个重要的滞育关联基因的表达量变化趋势与转录组数据结果基本一致。【结论】本研究初步明确了西伯利亚蝗卵滞育调控的重要代谢途径,并筛选出20个滞育关联基因,为后续深入研究该物种的适应机理奠定了基础。     

沙葱萤叶甲卵滞育的转录组学分析

【目的】建立沙葱萤叶甲Galeruca daurica滞育卵转录组数据库,挖掘卵滞育相关的基因以及代谢和信号通路,在转录组水平探讨卵滞育的分子机制。【方法】采用Illumina NovaSeq6000高通量测序平台对沙葱萤叶甲滞育卵与解除滞育卵进行转录组测序,并进行生物信息学分析;利用DESeq软件分析沙葱萤叶甲滞育卵与解除滞育卵中的差异表达基因,对差异表达基因进行KEGG通路富集分析;利用qRT PCR技术对10个差异表达基因的表达模式进行验证。【结果】基于沙葱萤叶甲滞育卵与解除滞育卵转录组测序结果,共获得53 389个unigene,其中差异表达基因2 145个,24个差异表达基因与保幼激素信号及脂肪酸生物合成和降解相关。与解除滞育卵相比,滞育卵转录组中1 297个基因上调表达,富集于124条KEGG通路,其中核糖体通路显著富集;848个基因下调表达,富集于73条KEGG通路,其中MAPK信号通路和糖胺聚糖生物合成通路显著富集。qRT-PCR结果表明,随机选取的10个差异表达基因的表达趋势与RNA-Seq转录组测序结果完全一致。【结论】保幼激素,脂肪酸生物合成和降解,核糖体,MAPK信号及糖胺聚糖生物合成等通路可能在沙葱萤叶甲卵滞育调控中起着重要的作用。     

多组学分析在昆虫滞育中的应用

组学技术将生物的相关问题分别展现在基因、蛋白质和代谢物等不同层次水平上,已成为解读生命过程的重要工具。本文分别从转录组学、蛋白质组学、代谢组学以及组学间的联合应用等方面概括总结了组学技术在昆虫滞育研究中的应用情况,阐述了以转录组学、蛋白质组学和代谢组学为代表的多组学技术在昆虫滞育调控分子机制中取得的重要成果,并针对当前研究现状,对昆虫滞育中组学技术应用的前景和局限性进行了总结和展望,以期为昆虫滞育调控分子机制的研究提供参考依据。     

寄生取食Cry1Ab杀虫蛋白的粘虫幼虫对伞裙追寄蝇寄生率及生长发育的影响

【Aim】 To demonstrate the effect of transgenic Bt-crop on the bionomics of the tachinid fly Exorista civilis Rondani, the parasitism rate and life history parameters of E. civilis developed from larvae of the oriental armyworm, Mythimna separata (Walker), fed on artificial diets with Cry1Ab toxin were investigated in laboratory. 【Methods】 M. separata larvae were fed on diets containing 0, 3.125, 6.25, 12.5 and 25 μg/g of Cry1Ab toxin, respectively, and used as the host for E. civilis. The parameters related to the parasitism and the growth and development of E. civilis on the host were observed and recorded. 【Results】 The results showed that the parasitism rate and fecundity of the fly on M. separata larvae feeding on diets containing various doses of Cry1Ab protein were insignificantly different (P≥0.05), suggesting that host selective behavior of the E. civilis is not affected by the dose of Bt-toxin in the caterpillar. The developmental period (egg-larva, pupa, adult oviposition and generation), emergence rate, sex ratio, and fecundity of E. civilis developed from M. separata larvae treated by various concentrations of Cry1Ab toxin were insignificantly different (P≥0.05). However, the survival rate of the maggots in the host feeding on diet containing 3.125 μg/g of Cry1Ab toxin was significantly greater than that of the control and the rest treatments (P<0.05), while insignificantly different among the remained 4 treatments (P≥0.05). The pupal weight significantly declined as the concentration of Cry1Ab toxin fed by their hosts increased (P<0.05). The pupal weight in the control group was 49.8 mg, while that in treatment groups of 6.25 and 25 μg/g Cry1Ab toxin was only 41.0 and 36.7 mg, respectively. 【Conclusion】 These results indicate that parasitizing host M. separata larvae fed with Cry1Ab toxin has no dramatically negative effect on parasitoid E. civilis. This study provides a basis for the evaluation of the risk of transgenic Bt-crops on the tachinid parasitoids in fields.     

The genus Campylocheta (Diptera: Tachinidae) from Japan

Seven new species of Campylocheta are described and illustrated from Japan: abdominalis from Hokkaido, Honshu and Kyushu, flaviceps from Honshu and Tsushima, grisea from Kyushu, argenticeps from Honshu, bisetosa from Hokkaido and Honshu, hirticeps from Hokkaido, Honshu and Tsushima, and suwai from Hokkaido. Campylocheta dentifera Richter and C. umbrinervis Mesnil are redescribed and a key to nine Japanese species is provided.     

Genetic Diversity of Sturmiopsis parasitica Curran (Diptera: Tachinidae)

Sturmiopsis parasitica Curran (Diptera: Tachinidae) is a widely spread parasitoid of various lepidopteran stem borers including Eldana saccharina Walker (Lepidoptera: Pyralidae), Busseola fusca (Fuller) and Sesamia calamistis Hampson (Lepidoptera: Noctuidae) in western, eastern and southern Aenica. As the Aenican sugarcane stalk borer, E. saccharina, is currently the most economically important insect pest in South Aenican sugarcane there is an urgent need to develop a control strategy for the management of this pest. S. parasitica has been tested as a biological control agent against E. saccharina with limited success. In seeking possible reasons for this limited success we tested whether there is genetic differentiation among populations of S. parasitica and whether there are hostassociated lineages of S. parasitica enom B. fusca and E. saccharina.

To assess these hypotheses, DNA sequences of cytochrome oxidase I (COI), a mitochondrial proteincoding gene, were obtained enom fifteen specimens collected in western, eastern and southern Aenica. Phylogenetic analysis of these sequences using maximum parsimony grouped the specimens into two main clades, one of which is further subdivided. Examination of pairwise sequence divergence levels supports the hypothesis of two cryptic lineages. However, further supportive evidence is necessary before revising the taxonomy of the species.     

History of tachinid classification (Diptera,Tachinidae)

The history of the classification of the Tachinidae (Diptera) is traced from Meigen to the present. The contributions of Robineau-Desvoidy, Townsend, Villeneuve, Mesnil, Herting, Wood and many others are discussed within a chronological, taxonomic, and geographic context. The gradual development of the Tachinidae into its modern concept as a family of the Oestroidea and the emergence of the classificatory scheme of tribes and subfamilies in use today are reviewed. Certain taxa that have in the past been difficult to place, or continue to be of uncertain affinity, are considered and some are given in a table to show their varied historical treatments. The more significant systematic works published on the Tachinidae in recent decades are enumerated chronologically.     

Morphological phylogeny and classification of Winthemiini (Diptera: Tachinidae: Exoristinae)

Winthemiini is a worldwide tribe in the subfamily Exoristinae (Diptera: Tachinidae) with 200 species in 16 genera. We confirm the monophyly of Winthemiini and examine relationships among the constituent genera based on a parsimonious analysis of adult morphological characters for 53 species representing 12 out of 16 currently recognized Winthemiini genera. As a result, Winthemiini is divided into three major clades, with relationships as follows: ((Rhaphiochaeta [Ossidingia, Nemorilla]) ((Hemisturmia [Avibrissosturmia, Triodontopyga]) ([Smidtia, Winthemia])). A revised classification system for Winthemiini is proposed, recognizing 12 genera. Four new synonymies are proposed – Diotrephes and Chesippus as junior synonyms of Smidtia, and Hemisturmiella and Parachetolyga as junior synonyms of Winthemia – along with four new combinations: Winthemia brasiliana (Guimarães) comb.n. , W. metopia (Bischof) comb.n. , Smidtia atriventris (Walker) comb.n. , and S. notialis (Reinhard) comb.n.     

松毛虫狭颊寄蝇实验种群生态学研究

松毛虫狭颊寄蝇(Carcelia matsukarehae)是松毛虫重要的寄生天敌之一。在控制松毛虫自然种群增长中起重要的作用。本文在15℃、18℃、22℃、25℃、29℃、32℃6个恒温。相对湿度为70％～85％,光照为12：12(L：D)的条件下研究了松毛虫狭颊寄蝇的生态学特性。结果表明,松毛虫狭颊寄蝇的世代发育起点温度是5．23℃。积温为523．73日·度。成虫寿命在没有补充营养的条件下为1．3～8．06d,喂以30％蜜糖水。寿命可以从9．63d延长到36．42d。成虫产卵的最适温度为236℃,每雌最大产量为86粒．种群增长最适温度22～25℃．以近似方法计算22℃和25℃下实验种群繁殖特征生命表参数。在22℃,R0、T0、rc和A值分别为24．89、37．33、0．086和1．089。在25℃时分别为20．01、32．38、0．09和1．10．22℃时种群最大LxMx出现在成虫羽化后第33～38天。25℃时的LxMx最大值出现在成虫羽化后第29～34天。     

A revision of the genus Trixa Meigen （Diptera： Tachinidae）

The genus Trixa Meigen, 1824 is revised. Dexiotrix Villeneuve, 1936 and Trixella Mesnil, 1980, each of which was sometimes treated as a distinct genus, are treated as junior synonyms of Trixa Meigen. Two species from Sichuan and Yunnan, China, are described as new to science, viz. Trixa chinensis sp. nov. and T. chaoi sp. nov. T. alpina Meigen is treated as a junior synonym of T. caerulescens Meigen. T. nox (Shima) and T.pubiseta (Mesnil) are newly recorded from China. Males of T. pubiseta (Mesnil) and T.longipensis (Villeneuve) are described for the first time. Diagnoses, figures and a key to twelve species in Trixa are given.