肠道菌群缺失在紫杉醇诱导的神经病理性疼痛中的作用

探索肠道菌群缺失对紫杉醇诱导的神经病理性疼痛行为的影响及相关机制。

32只C57雄性小鼠随机分为4组（n=8）：对照组（Control组）、抗生素组（ASC组）、紫杉醇组（PTX组）和抗生素+紫杉醇组（PTX+ASC组）。紫杉醇造模前,抗生素组小鼠口服ASC三联广谱抗生素（1 mg/mL）,持续2周。第1、3、5、7天腹腔注射紫杉醇（2 mg/kg）建立神经病理性疼痛模型。紫杉醇给药前和给药后第14天分别测定小鼠的热缩足潜伏期（TWL）和机械缩足反应阈（MWT）。行为学实验结束后,取小鼠粪便样本（5～6粒/只）用于16S rRNA扩增子测序分析。Western blot法检测小鼠脊髓水平Toll样受体4（TLR4）蛋白和核因子κB（NF-κB）蛋白的表达情况。免疫荧光检测脊髓星形胶质细胞的活化情况。ELISA实验检测脊髓内肿瘤坏死因子α（TNF-α）和白细胞介素−1β（IL-1β）的表达水平。

与对照组相比,口服ASC抗生素的小鼠,肠道菌群在科水平上Muribaculaceae、乳杆菌科和阿克曼菌科相对丰度显著下降（P＜0.05）;紫杉醇2 mg/kg造模后,小鼠机械/热痛阈值显著下降（P＜0.05）,小鼠脊髓TLR4和NF-κB蛋白和促炎性因子TNF-α、IL-1β表达水平显著升高（P＜0.05）,脊髓星形胶质细胞异常活化（P＜0.05）。与紫杉醇组相比,抗生素+紫杉醇组小鼠的机械/热痛阈值显著升高（P＜0.05）。小鼠脊髓内TLR4和NF-κB蛋白和TNF-α、IL-1β的表达显著降低（P＜0.05）,星形胶质细胞活化水平显著减弱（P＜0.05）。

ASC抗生素三联给药造成的肠道菌群缺失可缓解紫杉醇诱导的小鼠神经病理性疼痛,并可抑制紫杉醇诱导的脊髓TLR4/NF-κB信号通路蛋白的过表达,星形胶质细胞活化和炎性反应。

     

From genes to ecosystems: a synthesis of the effects of plant genetic factors across levels of organization

Using two genetic approaches and seven different plant systems, we present findings from a meta-analysis examining the strength of the effects of plant genetic introgression and genotypic diversity across individual, community and ecosystem levels with the goal of synthesizing the patterns to date. We found that (i) the strength of plant genetic effects can be quite high; however, the overall strength of genetic effects on most response variables declined as the levels of organization increased. (ii) Plant genetic effects varied such that introgression had a greater impact on individual phenotypes than extended effects on arthropods or microbes/fungi. By contrast, the greatest effects of genotypic diversity were on arthropods. (iii) Plant genetic effects were greater on above-ground versus below-ground processes, but there was no difference between terrestrial and aquatic environments. (iv) The strength of the effects of intraspecific genotypic diversity tended to be weaker than interspecific genetic introgression. (v) Although genetic effects generally decline across levels of organization, in some cases they do not, suggesting that specific organisms and/or processes may respond more than others to underlying genetic variation. Because patterns in the overall impacts of introgression and genotypic diversity were generally consistent across diverse study systems and consistent with theoretical expectations, these results provide generality for understanding the extended consequences of plant genetic variation across levels of organization, with evolutionary implications.     

Participant Profiling and Pattern of Crop-Foraging in Chacma Baboons (<Emphasis Type="Italic">Papio hamadryas ursinus</Emphasis>) in Zimbabwe: Why Does Investigating Age–Sex Classes Matter?

Transformation and loss of natural habitat to urbanization and agriculture provide new opportunities for primates to feed on anthropogenic food sources. Currently, mitigation strategies fail to target the individuals responsible for initiating and maintaining this behavior. As primates mainly forage on crops in groups, we investigate the crop-foraging behavior of a group of 40 chacma baboons in Zimbabwe from the perspective of collective movements, i.e., when a group of animals move together in the same direction, thus resulting in a change of location. We collected data on 110 crop-foraging events during 35 days in March–April 2014. We recorded baboon movement and behavior with a camcorder and obtained further information through video analysis. Most crop-foraging events involved less than 20% of the troop and lasted less than 3 min. Although crop-foraging parties were composed of all age–sex classes, adult females and particularly adult males initiated most crop-foraging events and made direct movements (without stopping on the road) more often than nonadult participants. Baboons made up to five successive attempts to crop forage in a single crop-foraging event. Neither the number of participants nor the success of the crop-foraging events increased over the successive attempts. Finally, crop-foraging events were more successful and more frequent in unguarded areas than in guarded areas. These results suggest that group members are highly synchronized and that crop-foraging is based on a collective decision such as classical foraging movements. In addition, the short duration of the crop-foraging events might prevent detection of baboons by farmers. The more frequent initiation of crop-foraging by adults compared to nonadults might be explained by greater energetic needs or a greater tendency of adults to take risks. These preliminary data can help inform long-term strategies for farmers to reduce crop losses to baboons, as guarding helps reduce damage but does not prevent it.     

基于ISSR标记的辽宁4个东北林蛙种群遗传多样性分析

辽宁是东北林蛙Rana dybowskii主要分布地之一,种群数量巨大,其群体遗传多样性有待评估.本研究应用ISSR标记技术对东北林蛙4个种群105个样本进行研究,5个引物共获得44条清晰谱带,4个种群的多态位点率均大于75%,Nei's基因多样性为0.2851,Shannon信息指数为0.4476,显示了较高的遗传多样性.对遗传分化系数、Nei's遗传距离、AMOVA分子变异巢式方差分析和F-统计量等遗传参数的统计结果表明,辽宁东北林蛙种群间已经出现一定程度的遗传分化,分析认为,自然屏障(高山和平原等)以及栖息地片段化是其遗传分化形成的主要因素.     

Haemosporidian Parasites of Antelopes and Other Vertebrates from Gabon,Central Africa

Re-examination, using molecular tools, of the diversity of haemosporidian parasites (among which the agents of human malaria are the best known) has generally led to rearrangements of traditional classifications. In this study, we explored the diversity of haemosporidian parasites infecting vertebrate species (particularly mammals, birds and reptiles) living in the forests of Gabon (Central Africa), by analyzing a collection of 492 bushmeat samples. We found that samples from five mammalian species (four duiker and one pangolin species), one bird and one turtle species were infected by haemosporidian parasites. In duikers (from which most of the infected specimens were obtained), we demonstrated the existence of at least two distinct parasite lineages related to Polychromophilus species (i.e., bat haemosporidian parasites) and to sauropsid Plasmodium (from birds and lizards). Molecular screening of sylvatic mosquitoes captured during a longitudinal survey revealed the presence of these haemosporidian parasite lineages also in several Anopheles species, suggesting a potential role in their transmission. Our results show that, differently from what was previously thought, several independent clades of haemosporidian parasites (family Plasmodiidae) infect mammals and are transmitted by anopheline mosquitoes.     

How Random Is Social Behaviour? Disentangling Social Complexity through the Study of a Wild House Mouse Population

Out of all the complex phenomena displayed in the behaviour of animal groups, many are thought to be emergent properties of rather simple decisions at the individual level. Some of these phenomena may also be explained by random processes only. Here we investigate to what extent the interaction dynamics of a population of wild house mice (Mus domesticus) in their natural environment can be explained by a simple stochastic model. We first introduce the notion of perceptual landscape, a novel tool used here to describe the utilisation of space by the mouse colony based on the sampling of individuals in discrete locations. We then implement the behavioural assumptions of the perceptual landscape in a multi-agent simulation to verify their accuracy in the reproduction of observed social patterns. We find that many high-level features – with the exception of territoriality – of our behavioural dataset can be accounted for at the population level through the use of this simplified representation. Our findings underline the potential importance of random factors in the apparent complexity of the mice''s social structure. These results resonate in the general context of adaptive behaviour versus elementary environmental interactions.