Use of time in a decision‐making process by a parasitoid

1. Time perception is seldom studied in invertebrates, with the limited experimental evidence being insufficient to provide a comprehensive pattern of the capacity of invertebrates to measure time and use it in decision‐making processes. 2. In this study, it was hypothesized that insect parasitoids have evolved the capacity to measure time precisely and to use it to optimize foraging decisions related to host exploitation. To examine time perception in females of the gregarious egg parasitoid Trichogramma euproctidis, the present study used their ability to adjust their investment (number of eggs laid) in a host to the initial transit duration (interval between the first contact with the host and the following contact with the substrate). Females utilize this method to assess host egg size, as a large egg necessarily requires more time to evaluate than a small host. In this study, the initial transit duration for a given sized egg was artificially extended by suspending it. 3. For similar sized hosts, female T. euproctidis significantly increased both oviposition duration and progeny allocation following a longer initial transit duration. 4. These results demonstrate the intrinsic capacity of this parasitoid to measure time and to adjust their progeny investment accordingly. This is believed to be one of the few demonstrations of a retrospective measure of time in an invertebrate.     

Taxonomy of the Houbara Bustard Chlamydotis undulata subspecies considered on the basis of sexual display and genetic divergence

The Houbara Bustard Chlamydotis undulata is a polytypic species with three subspecies classified according size, colour and distribution: C. u. undulata, C. u. fuertaventurae and C. u. macqueenii. A comparative study of the male display behaviour of these three subspecies has shown similarities between C. u. undulata and C. u. fuertaventurae , whereas appreciable differences exist in the visual and auditory aspects of the display between C. u. undulata and C. u. macqueenii. These observations make the current taxonomy of Houbara Bustard questionable, particularly in view of the major importance of the sexual display in bird speciation processes. Furthermore, DNA analysis of the cytochrome b gene indicates the existence of a significant differentiation between the C. u. undulata and C. u. macqueenii populations. These findings indicate the need for a revision of the taxonomy of genus Chlamydotis which should separate the macqueenii and undulata populations at species rank. Until further investigations are completed, C. u. fuertaventurae should be kept as a subspecies of undulata since the courtship display is alike in both populations.     

Theoretical habitat templets, species traits, and species richness: Plecoptera and Ephemeroptera in the Upper Rhône River and its floodplain

• 1 Ephemeroptera and Plecoptera in two sites of the Upper Rhône River (France) were examined using multivariate analyses to determine: (i) relationships among seventeen species traits; (ii) habitat utilization of the fifty-five species present; (iii) the relationship between species traits and habitat utilization; (iv) trends of species traits and species richness in a framework of spatial and temporal habitat variability.
• 2 The species traits having the highest correlation ratios correspond to reproduction or life cycle, behavioural, and morphological characteristics. According to their traits, species of Baetidae, Caenidae, and Leptophlebiidae (Ephemeroptera) are opposite species of Perlidae and Perlodidae (Plecoptera).
• 3 The distribution of species in thirteen habitat types of the Upper Rhône River floodplain demonstrates a transverse gradient from the main channel to the oxbow lakes. Plecoptera are restricted to the different main channel habitats; in contrast, Ephemeroptera families have a broader distribution with Baetidae and Leptophlebiidae occurring in most floodplain habitats.
• 4 Plecoptera exhibit a significant relationship between species traits and habitat utilization but no relationship is evident for Ephemeroptera. Baetidae use many habitat types and have diverse species traits; in contrast, Leptophlebiidae, Heptageniidae, and Caenidae use many habitat types but each family has a rather uniform set of traits.
• 5 Trends in species traits were significantly related to both the spatial and temporal variability of habitats. Considering only temporal variability, the distribution of species trait modalities (= categories) corresponded well to predictions on trends in the river habitat templet for ‘minimum age at reproduction’ and ‘potential longevity’, and in general for ‘descendants per reproductive cycle’, ‘reproductive cycles per year’, ‘potential size’, and ‘body flexibility’ trends in six other traits did not match predictions.
• 6 No trends in species richness were evident in spatial–temporal framework of habitat variability.

     

蚕豆（Vicia faba L．）叶肉细胞中ABA的胶体金免疫电镜定位

利用胶体金免疫电镜定位技术对蚕豆叶肉细胞中ＡＢＡ定位的研究表明,在以ＡＢＡ抗体处理的切片中,叶绿体有大量的金颗粒标记,细胞质和细胞核也有金颗粒标记,但液泡和细胞壁中没有金颗粒标记。免疫染色前用胰蛋白酶处理可显著增强金颗粒标记密度,而不用ＥＤＣ固定或以免疫前兔血清处理的切片中几乎没有金颗粒标记。本实验为蚕豆叶肉细胞中ＡＢＡ的分布提供了直接的证据并说明了该技术是研究ＡＢＡ定位的一种可靠的方法。     

Diversity and evolution of leaflet anatomical characters in the Pterocarpus clade (Fabaceae: Papilionoideae)

Journal of Plant Research - The Pterocarpus clade includes 23 genera previously attributed to different Fabaceae tribes. The recent rearrangements of many genera in the clade do not recognize...     

非洲猪瘟病毒I226R蛋白抑制cGAS-STING通路介导的天然免疫应答

本研究旨在探究非洲猪瘟病毒(African swine fever virus, ASFV) I226R蛋白(I226R protein, pI226R)抑制cGAS-STING信号通路的作用机制。利用双荧光素酶报告系统和实时荧光定量PCR (real-time quantitative PCR, qPCR)证明pI226R显著抑制cGAS-STING通路介导的I型干扰素及干扰素刺激相关基因的产生。免疫共沉淀及激光共聚焦显微镜试验发现pI226R与cGAS蛋白相互作用。免疫印迹分析证明pI226R通过自噬-溶酶体途径促进cGAS蛋白的降解。同时,pI226R阻碍了cGAS与E3泛素连接酶三基序蛋白56 (tripartite motif protein 56, TRIM56)的结合,导致cGAS的单泛素化减弱,从而抑制了cGAS的活化和cGAS-STING通路的激活。总之,本研究证明ASFV pI226R通过拮抗cGAS进而抑制宿主的抗病毒天然免疫反应,进一步增加了对研究ASFV免疫逃逸机制的理解,为疫苗的研发提供了理论基础。     

S－美芬妥英羟化代谢多态性的分子机制研究进展

人群中存在着Ｓ－美芬妥英羟化代谢多态性。从人肝微粒体已分离出Ｓ－美芬妥英羟化酶。在基因克隆研究中已分离出与该羟化酶活性有关的Ｐ４５０ｃＤＮＡ,属Ｐ４５０２Ｃ１９。最近报道,人肝中Ｐ４５０２Ｃ１９的含量和催活Ｓ－美芬妥英羟化活性密切相关,其弱代谢者主要由于ＣＹＰ２Ｃ１９的外显子５单碱基对（Ｇ→Ａ）的变异,使核苷酸序列错位而产生无功能的Ｐ４５０蛋白的结果。     

羽扇豆醇通过抑制RhoA-ROCK1信号通路抑制结肠癌细胞增殖

该文探讨了羽扇豆醇(Lupeol)对人结肠癌HCT116和SW620细胞增殖的影响及相关作用机制。使用不同浓度的Lupeol处理HCT116和SW620细胞后,用MTT法检测细胞活性,CCK8法检测细胞增殖能力,平板克隆实验检测细胞克隆形成能力,流式细胞术检测细胞周期和细胞凋亡,(quantitative real-time PCR,qPCR)和Western blot检测相应mRNA和蛋白表达水平,免疫荧光检测β-Catenin蛋白细胞内分布情况。通过构建shRNA敲低两种结肠癌细胞中RhoA,进一步研究Lupeol影响细胞增殖的分子机制。结果显示,Lupeol处理后,HCT116和SW620细胞增殖能力明显下降,克隆形成能力受到抑制,细胞周期阻滞于G0/G1期,细胞内RhoA、ROCK1、β-Catenin、Cyclin D1 mRNA和蛋白表达水平均显著下降,β-Catenin蛋白胞质和胞膜上分布减少。敲低RhoA后抑制了细胞增殖,同时使得RhoA-ROCK1-β-Catenin信号通路蛋白受到抑制,β-Catenin蛋白胞质和胞膜上分布减少。综上所述,Lupeol可通过抑制RhoA-ROCK1信号通路,抑制β-Catenin蛋白表达,进而抑制HCT116和SW620细胞增殖,Lupeol有望成为临床结肠癌治疗的新药物。     

Characterization,Toxicity, and Optimization for the Growth and Production of Bacteriocin-like Substances by Lactobacillus curvatus

Probiotics and Antimicrobial Proteins - This study aimed to characterize, evaluate toxicity and optimize the conditions for the growth and production of bacteriocin-like substances by Lactobacillus...