egg deposition

卵沉积
  • 文章类型: Journal Article
    对昆虫的植物识别的知识在很大程度上限于针对吸汁昆虫的一些抗性(R)基因。超敏反应(HR)表征了几种病理性系统中依赖于R基因的单基因植物性状。类似HR的细胞死亡可以由卷心菜白蝴蝶的卵触发(Pierisspp。),卷心菜作物的害虫(芸苔属。),在摄食损害发生之前,降低卵的存活率并代表有效的植物抗性性状。这里,我们对黑芥菜中的菜青虫卵诱导的HR样细胞死亡进行了遗传定位(B.nigra).我们表明,HR样细胞死亡分离为孟德尔性状,并在B3号染色体上确定了一个显性基因座,称为PEK(Pieriseg-killing)。11个基因位于大约50kb的区域,包括编码细胞内TIR-NBS-LRR(TNL)受体蛋白的基因簇。PEK基因座在我们作图种群的亲本种质之间以及黑芽孢杆菌参考基因组之间具有高度多态性。我们的研究是第一个鉴定出可能参与黑芽孢杆菌昆虫卵诱导的HR样细胞死亡的单个基因座的研究。进一步精细映射,比较基因组学和PEK基因座的验证将揭示这些TNL受体在杀卵HR中的作用。
    Knowledge of plant recognition of insects is largely limited to a few resistance (R) genes against sap-sucking insects. Hypersensitive response (HR) characterizes monogenic plant traits relying on R genes in several pathosystems. HR-like cell death can be triggered by eggs of cabbage white butterflies (Pieris spp.), pests of cabbage crops (Brassica spp.), reducing egg survival and representing an effective plant resistance trait before feeding damage occurs. Here, we performed genetic mapping of HR-like cell death induced by Pieris brassicae eggs in the black mustard Brassica nigra (B. nigra). We show that HR-like cell death segregates as a Mendelian trait and identified a single dominant locus on chromosome B3, named PEK (Pieris  egg- killing). Eleven genes are located in an approximately 50 kb region, including a cluster of genes encoding intracellular TIR-NBS-LRR (TNL) receptor proteins. The PEK locus is highly polymorphic between the parental accessions of our mapping populations and among B. nigra reference genomes. Our study is the first one to identify a single locus potentially involved in HR-like cell death induced by insect eggs in B. nigra. Further fine-mapping, comparative genomics and validation of the PEK locus will shed light on the role of these TNL receptors in egg-killing HR.
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  • 文章类型: Journal Article
    背景:日本血吸虫与人类结直肠癌之间的关联由来已久;然而,这种联系仍然缺乏研究,缺乏全面的实验支持。
    目的:各种流行病学和病理学研究已经确立了慢性炎症作为诱导结直肠癌的主要因素的作用。这篇综述的目的是介绍日本血吸虫与结直肠癌的相关性。
    结果:导致结直肠癌诱导和进展的机制以及其诊断和治疗被强调。Further,各种方法,包括大规模药物管理,使用新药和疫苗,凋亡的作用,和组蛋白修饰酶,已经描述了可以预防血吸虫感染本身或可以检查它达到晚期。
    结论:流行病学,临床,病理和手术研究表明,日本血吸虫是引起结直肠癌的原因。然而,需要全面的临床研究来支持和全球接受这一观点.Further,可以采用这项工作中强调的方法来治疗血吸虫感染或解决癌症的诱导和进展。
    BACKGROUND: An association between Schistosoma japonicum and colorectal cancer in humans has been known since a long time; however, this association remains understudied and lacks comprehensive experimentation support.
    OBJECTIVE: Various epidemiological and pathological studies have established the role of chronic inflammation as a major factor behind the induction of colorectal cancer. The aim of this review is to present the current knowledge on the association of Schistosoma japonicum with colorectal cancer.
    RESULTS: Mechanisms which lead to induction and progression of colorectal cancer are highlighted along with diagnosis and treatment for the same. Further, various methodologies, including mass drug administration, use of new drugs and vaccines, role of apoptosis, and histone-modifying enzymes, have been described which can either prevent the schistosomal infection itself or can check it from reaching an advanced stage.
    CONCLUSIONS: Epidemiological, clinical, pathological and surgical studies suggest that Schistosoma japonicum is responsible for induction of colorectal cancer. However, thorough clinical studies are required to support and globally accept this notion. Further, methodologies highlighted in this work can be employed in order to take care of schistosomal infection or address the cancer induction and progression.
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  • 文章类型: Journal Article
    昆虫发育的卵阶段容易受到环境条件的波动和天敌的攻击。保护装置是避免对鸡蛋造成非生物和生物损害的有效手段。虽然有些昆虫用粪便作为保护装置,很少有研究集中在使用粪便保护鸡蛋,缺乏研究机制的研究。食水甲虫的雌性,Coelostomastultum,通常产卵,并用茧和粪便覆盖它们。双重防御装置的功效,然而,仍然不确定。这里,我们进行了野外观察和实验室实验,以评估带有粪便涂层的茧对卵的捕食保护作用,并确定这种防御的持续时间和机制。我们的发现表明,鸡蛋茧上的粪便保护鸡蛋免受药丸虫子的捕食,寻常树,和沼泽slu,Deroceraslaeve.实验室实验表明,粪便涂层的防御作用可维持三天,并每天降低。卵茧上具有粪便涂层的双重保护特性可保护卵免受C.stultum的即时捕食压力。药丸虫的行为模式和卵的捕食率表明,当药丸虫的触角接触粪便时,C.stultum中的粪便涂层行为会保护具有化合物和质地伪装的卵。重要的是要注意,要使这种辩护有效,粪便的化学和质地应与产卵部位相似。
    The egg stage in insect development is vulnerable to fluctuations in environmental conditions and attacks by natural enemies. Protective devices are effective means of avoiding both abiotic and biotic damage to eggs. Although some insects use their faeces as a protective device, few studies have focused on using faeces for egg protection, and studies that examined the mechanism are lacking. Females of a water scavenger beetle, Coelostoma stultum, typically lay eggs and coat them with cocoons and their faeces. The efficacy of a double defensive device, however, remains uncertain. Here, we conducted field observations and laboratory experiments to assess the protective effects of cocoons with faecal coating on eggs against predation and determine the duration and mechanisms of this defence. Our findings reveal that the faeces on the egg cocoon protected eggs from predation by the pill bugs, Armadillidium vulgare, and marsh slugs, Deroceras laeve. Laboratory experiments showed that the defensive effect of faecal coating was maintained for three days and decreased daily. The double protective traits with faecal coating on the egg cocoons protected the eggs from instense predation pressure in C. stultum. The behavioural patterns of the pill bugs and egg predation rates indicate that the faecal coating behaviour in C. stultum protects eggs with chemical compounds and textural camouflage in mud when the antennae of the pill bugs touch faeces. It is important to note that for this defence to be effective, the chemistry and texture of the faeces should be similar to that of the oviposition sites.
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  • 文章类型: Journal Article
    昆虫侵染对植物抗草食动物防御的长期影响的研究往往集中在摄食引起的损害上。整个昆虫世代的侵染,包括卵沉积以及喂食昆虫,经常被忽视。虽然有越来越多的证据表明,昆虫卵的存在可以在短期内增强植物对孵化幼虫的抗草食动物防御,人们对昆虫的侵扰知之甚少,包括昆虫卵沉积,长期影响植物防御。我们通过研究昆虫侵染对小榆树对随后侵染的防御的长期影响来解决这一知识空白。在温室实验中,榆树暴露于榆叶甲虫(ELB,黄曲霉)侵染(成人,鸡蛋,幼虫)。此后,树木在模拟的冬季条件下撒下叶子,并在模拟的夏季条件下重新生长叶子后,用ELB重新出没。在几个发育参数方面,ELB在先前受感染的榆树上表现较差。苯丙素山奈酚和槲皮素的浓度,它们参与了鸡蛋介导的,对榆树防御的短期影响,在先前受感染的树木的ELB挑战的叶子中,比在未受感染的树木的挑战的叶子中略高。参与苯丙素途径的几个基因的表达,茉莉酸信号,DNA和组蛋白修饰似乎受到ELB侵染的影响;然而,先前的侵染并没有改变这些基因的表达强度。几种植物激素的浓度在先前侵染的树木和原始树木的当前受到攻击的叶子中受到类似的影响。我们的研究表明,专门的昆虫事先侵染榆树会导致在接下来的生长季节适度改善对随后侵染的防御能力。先前的侵染为植物在防御孵化幼虫时对卵沉积的反应表现出的短期增强剂效应增加了长期效应。
    The studies of the long-term effects of insect infestations on plant anti-herbivore defences tend to focus on feeding-induced damage. Infestations by an entire insect generation, including egg depositions as well as the feeding insects, are often neglected. Whilst there is increasing evidence that the presence of insect eggs can intensify plants\' anti-herbivore defences against hatching larvae in the short term, little is known about how insect infestations, including insect egg depositions, affect plant defences in the long term. We addressed this knowledge gap by investigating long-term effects of insect infestation on elm\'s (Ulmus minor Mill. cv. \'Dahlem\') defences against subsequent infestation. In greenhouse experiments, elms were exposed to elm leaf beetle (ELB, Xanthogaleruca luteola) infestation (adults, eggs and larvae). Thereafter, the trees cast their leaves under simulated winter conditions and were re-infested with ELB after the regrowth of their leaves under simulated summer conditions. Elm leaf beetles performed moderately worse on previously infested elms with respect to several developmental parameters. The concentrations of the phenylpropanoids kaempferol and quercetin, which are involved in egg-mediated, short-term effects on elm defences, were slightly higher in the ELB-challenged leaves of previously infested trees than in the challenged leaves of naïve trees. The expression of several genes involved in the phenylpropanoid pathway, jasmonic acid signalling, and DNA and histone modifications appeared to be affected by ELB infestation; however, prior infestation did not alter the expression intensities of these genes. The concentrations of several phytohormones were similarly affected in the currently challenged leaves of previously infested trees and naïve trees. Our study shows that prior infestation of elms by a specialised insect leads to moderately improved defences against subsequent infestation in the following growing season. Prior infestation adds a long-term effect to the short-term enhancer effect that plants show in response to egg depositions when defending against hatching larvae.
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  • 文章类型: Journal Article
    据称,Calliphoridae家族的苍蝇在人类尸体或腐肉上表现出对伤口的强烈吸引力和优先定殖。法医昆虫学中的这一广为流传的概念是基于令人惊讶的经验性研究,这些研究检查了食尸双翅目对脊椎动物伤口的产卵行为。在本研究中,在受控的实验室条件和室外城市环境下,在10小时的测试期间,检查了Calliphoravicina对死后锐器伤造成的仔猪的产卵行为。三种苍蝇(C.维吉娜,C.livida和Cynomyacadaverina)在野外研究中将卵存放在受伤和未受伤的仔猪上,尽管所有产卵中的80%以上是由C.vicina产卵。对于所有物种来说,产卵主要发生在头部,包括眼睛,耳朵,鼻子和嘴巴,在身体的其他位置不太常见。从未在伤口或伤口附近发现鸡蛋。C.vicina在实验室条件下显示了类似的产卵模式,除了在过度拥挤的条件下有限的卵子沉积在伤口中。在后一种情况下,卵沉积仅占成年苍蝇生殖总产量的0.14%。研究结果不支持以下论点:由于尖锐的穿透性创伤而导致的伤口中的产卵优先。
    Flies in the family Calliphoridae are purported to demonstrate a strong attraction to and preferential colonization of wounds when present on human corpses or carrion. This well-circulated concept in Forensic Entomology is based on surprisingly few empirical studies that have examined the oviposition behavior of necrophagous Diptera toward wounds of vertebrate animals. In the present study, the oviposition behavior of Calliphora vicina toward piglets inflicted with postmortem sharp force trauma was examined during a 10-h test period under controlled laboratory conditions and in an outdoor urban environment. Three species of flies (C. vicina, C. livida and Cynomya cadaverina) deposited eggs on wounded and non-wound piglets during the field studies, although more than 80% of all eggs laid were by C. vicina regardless of wound status. For all species, oviposition occurred predominately on the head, including in eyes, ears, nose and mouth, and less frequently in other locations on the body. Eggs were never found in or near wounds. Similar oviposition patterns were displayed by C. vicina under laboratory conditions, with the exception for limited egg deposition in wounds under overcrowded conditions. In this latter scenario, egg deposition represented only 0.14% of the total reproductive output of adult flies. The findings do not support the contention that calliphorids preferentially oviposit in wounds resulting from sharp force penetrating trauma.
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  • 文章类型: Journal Article
    Evolutionary arms-races between plants and insect herbivores have long been proposed to generate key innovations such as plant toxins and detoxification mechanisms that can drive diversification of the interacting species. A novel front-line of plant defence is the killing of herbivorous insect eggs. We test whether an egg-killing plant trait has an evolutionary basis in such a plant-insect arms-race. Within the crucifer family (Brassicaceae), some species express a hypersensitive response (HR)-like necrosis underneath butterfly eggs (Pieridae) that leads to eggs desiccating or falling off the plant. We studied the phylogenetic distribution of this trait, its egg-killing effect on and elicitation by butterflies, by screening 31 Brassicales species, and nine Pieridae species. We show a clade-specific induction of strong, egg-killing HR-like necrosis mainly in species of the Brassiceae tribe including Brassica crops and close relatives. The necrosis is strongly elicited by pierid butterflies that are specialists of crucifers. Furthermore, HR-like necrosis is linked to PR1 defence gene expression, accumulation of reactive oxygen species and cell death, eventually leading to egg-killing. Our findings suggest that the plants\' egg-killing trait is a new front on the evolutionary arms-race between Brassicaceae and pierid butterflies beyond the well-studied plant toxins that have evolved against their caterpillars.
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  • 文章类型: Journal Article
    卵是卵生动物直接暴露于环境中的第一个生命阶段,包括许多脊椎动物和大多数节肢动物。鸡蛋是脆弱和容易死亡的风险。在节肢动物中,最常见的卵子死亡因素之一是寄生虫的攻击。然而,在所有昆虫(子)顺序的一半以上中,没有攻击卵期的寄生虫。在这次审查中,我们探索可能的原因,解释为什么一些昆虫类群的卵没有被寄生。许多未受卵寄生虫攻击的昆虫(子)订单缺乏食草物种,除了一些值得注意的例外。我们认为导致避免卵寄生的因素是父母的卵护理,快速的卵子发育,小鸡蛋大小,藏鸡蛋,例如,将它们放入土壤中,涂鸡蛋涂层或有厚的绒毛膜防止鸡蛋渗透,Eusocity,和鸡蛋自相残杀。对宿主-寄生虫关联的定量网络分析表明,卵寄生虫的五个最特殊的属显示出相对于某些昆虫顺序的特异性模式,尤其是鳞翅目和半翅目,主要包括将卵存放在植物上的草食性物种。最后,我们讨论了许多反适应措施,特别是草食性物种已经发展起来,以降低受卵寄生虫攻击的风险。
    The egg is the first life stage directly exposed to the environment in oviparous animals, including many vertebrates and most arthropods. Eggs are vulnerable and prone to mortality risks. In arthropods, one of the most common egg mortality factors is attack from parasitoids. Yet, parasitoids that attack the egg stage are absent in more than half of all insect (sub)orders. In this review, we explore possible causes explaining why eggs of some insect taxa are not parasitized. Many insect (sub)orders that are not attacked by egg parasitoids lack herbivorous species, with some notable exceptions. Factors we consider to have led to escape from egg parasitism are parental egg care, rapid egg development, small egg size, hiding eggs, by e.g. placing them into the soil, applying egg coatings or having thick chorions preventing egg penetration, eusociality, and egg cannibalism. A quantitative network analysis of host-parasitoid associations shows that the five most-speciose genera of egg parasitoids display patterns of specificity with respect to certain insect orders, especially Lepidoptera and Hemiptera, largely including herbivorous species that deposit their eggs on plants. Finally, we discuss the many counteradaptations that particularly herbivorous species have developed to lower the risk of attack by egg parasitoids.
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  • 文章类型: Case Reports
    A case with breast schistosomiasis japonica was reported.
    [摘要] 本文报道 1 例乳房血吸虫病病例。.
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  • 文章类型: Journal Article
    The identification of volatile organic compounds (VOCs) leading to short-range attraction and oviposition of the European grapevine moth Lobesia botrana and European grape berry moth Eupoecilia ambiguella (Lepidoptera: Tortricidae) is crucial in order to establish bait-based decision support systems for control of these pests. Therefore, we developed a method to measure the real-time behavioral response of female moths to VOCs using a four-chamber olfactometer coupled with a video tracking system. Ten synthetic VOCs were selected for this study: (S)-(-)-perillaldehyde, (E)/(Z)-linalool oxide, (±)-limonene, linalool, (E)-β-caryophyllene, α/β-farnesene, (-)-α-cedrene, methyl salicylate and cumene. The effect of VOCs on egg deposition was determined using a dual-choice oviposition test, whereas perception by female antennae was verified using electroantennography (EAG). During video tracking, females responded to volatile compounds emitted by grapevine with higher antennae and ovipositor activity than to air control. (E)/(Z)-linalool oxide, cumene and (S)-(-)-perillaldehyde released ovipositor activity of L. botrana, while the latter provoked oviposition. (R)/(S)-limonene affected ovipositor activity of E. ambiguella, whereas none of the VOCs tested attracted for oviposition. The results suggest that females have the ability to perceive specific VOCs by the antennae but also by the ovipositor, which could attract or repel for egg deposition.
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  • 文章类型: Journal Article
    由于全球粮食生产需求的不断增长,建议采取新的策略,以实现可持续的粮食生产,而对自然资源的影响最小。应用化学农药的有希望的替代方法是实施对害虫具有抗性的作物。植物产生对各种攻击者有害的化合物,包括害虫;因此,开发其自然防御系统可能是开发抗虫作物的关键。有趣的是,一些植物拥有独特的第一道防线,可以在敌人变得破坏性之前消灭敌人:杀卵。昆虫卵可以触发(1)直接防御,主要包括导致卵子干燥的植物细胞组织生长或细胞死亡,被压碎或从植物上脱落或(2)间接防御,植物化学线索招募杀死卵或孵化幼虫(寄生虫)的天敌。植物对卵反应的后果是昆虫幼虫不孵化或发育受阻,减少对植物的损害。这里,我们概述了包括农作物在内的植物界中杀卵性状的普遍性和进化史。到目前为止,对杀卵性状的机制和遗传基础知之甚少。利用作物的杀卵防御特性是可持续减少作物产量损失的有希望的新途径。我们为种植杀卵作物和改善生物防治的新育种策略提供了建议。
    Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest-resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg-killing. Insect eggs can trigger (1) direct defenses, mostly including plant cell tissue growth or cell death that lead to eggs desiccating, being crushed or falling off the plant or (2) indirect defenses, plant chemical cues recruiting natural enemies that kill the egg or hatching larvae (parasitoids). The consequences of plant responses to eggs are that insect larvae do not hatch or that they are impeded in development, and damage to the plant is reduced. Here, we provide an overview on the ubiquity and evolutionary history of egg-killing traits within the plant kingdom including crops. Up to now, little is known on the mechanisms and on the genetic basis of egg-killing traits. Making use of egg-killing defense traits in crops is a promising new way to sustainably reduce losses of crop yield. We provide suggestions for new breeding strategies to grow egg-killing crops and improve biological control.
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