宏基因组学在哺乳动物肠道微生物中的应用

哺乳动物的肠道内栖息着庞大复杂的微生物群体，其微生物群体与宿主的消化吸收、物质的营养代谢和免疫功能密切相关，是影响机体健康的重要因素之一。随着分子生物学技术在肠道微生物领域的应用，特别是新一代测序技术的快速发展，使得人们对复杂的肠道微生物的研究更加深入。基于宏基因组学技术不仅能够研究肠道微生物组的多样性、揭示消化道微生物对宿主生理代谢的影响，还能进一步深入挖掘新的功能基因，并揭示宿主基因与微生物组间的互作关系和共同进化。作者综述了宏基因组学技术在哺乳动物肠道微生物中的主要应用和存在的不足，并展望了其在肠道微生物研究中的广阔应用前景，从而加深人们对肠道微生物影响宿主肠道健康作用的认识。     

基于红外相机技术的广东曲江沙溪省级自然保护区兽类资源分析

2019年7月,使用网格法布设了11台红外相机首次对广东曲江沙溪省级自然保护区大中型兽类资源进行了调查研究,调查累计102天,累计回收1 123个相机工作日的数据,共拍摄到兽类独立有效照片数103张,鉴定出兽类3目6科9种,分别为黄腹鼬Mustela kathiah、鼬獾Melogale moschata、斑林狸Prionodon pardicolor、豹猫Prionailurus bengalensis、野猪Sus scrofa、小麂Muntiacus reevesi、赤腹松鼠Callosciurus erythraeus、倭花鼠Tamiops maritimus和红腿长吻松鼠Dremomys pyrrhomer,其中,斑林狸和红腿长吻松鼠为沙溪自然保护区新纪录种;发现相对多度指数最高的兽类是野猪,为29.39,分布最广泛的地栖兽类是鼬獾;建立兽类累积曲线发现前31天兽类种数上升较快,后71天趋于平缓;研究进一步证实了红外相机技术可以作为保护区兽类补充调查的重要手段,可以在保护区兽类物种编目、相对多度指数、分布现状与凭证标本等收集上发挥重大作用。     

抗菌肽在哺乳动物防御系统中的作用

抗菌肽是近年来发现的广泛存在于自然界的一类阳离子抗菌活性肽，它们在宿主先天性免疫和适应性免疫中有重要作用。多数抗菌肽具有分子小、带正电、两亲性、抗菌谱广等共同特点。防御素和calhelicidins是哺乳动物的两大主要抗菌肽家族，它们通过抵抗致病菌入侵为宿主提供了第一道防线而对宿主具有先天的抗菌防御功能，其中一些多肽对未分化的树突状细胞、淋巴细胞有趋化性，另外还有诱导细胞因子生成、肥大细胞脱粒等作用，从而表明这些多肽能动员并增强宿主的先天性免疫和适应性免疫。本文主要对哺乳动物抗菌肽的一般性质、基因及其表达、在宿主防御中的作用、作用机理及研究前景进行了概述。     

哺乳动物肠上皮细胞的原代培养

肠上皮细胞是由多功能干细胞分化成的一个高度组织化系统.从离体的肠组织中分离的肠隐窝单位或肠上皮细胞可在数小时内保持高度活力,但要长期(达到10 d)原代培养肠上皮细胞仍然很困难.文章对肠上皮细胞的分离、鉴定、原代培养所需维持培养基和生长培养基的设计及培养条件等方面进行了综述.     

Characterizing Fine-scale Patterns of Alternative Agricultural Landscapes with Landscape Pattern Indices

Landscape pattern indices are common tools of landscape ecologists, affording comparisons of different study areas, or the same study area at different times. Since the advent of popular index-calculating software, more landscapes can be analyzed in short amounts of time, yet the behaviour of landscape pattern indices can vary for different contexts or data characteristics, complicating interpretation. I applied a selected set of landscape pattern indices to fine-resolution (3 m) data representing a highly fragmented landscape – Corn Belt Iowa agriculture – to investigate the performance of landscape pattern indices. Indices measured pattern attributes that affect the viability of small mammal populations, namely habitat proportion and connectivity and landscape grain size and heterogeneity. Results showed that the performance of indices for fine-resolution data can be highly variable, depending upon data and contextual issues like the presence of linear elements and the amount of habitat. For these Corn Belt landscapes good habitat proportions and patch sizes were small (commonly less than 10% and less than 1 ha, respectively), and connectivity was variable depending on the measure. Aggregation and mean nearest neighbour indices performed better than other connectivity indices. Fine-resolution data representing highly fragmented landscapes can raise difficulties for indices of landscape configuration. Landscape pattern indices require improvement to perform better for increasingly available fine-resolution data representing common landscape types.     

Conservation action in the Galàpagos: feral pig (Sus scrofa) eradication from Santiago Island

Introduced mammals are major drivers of extinction and ecosystem change. As omnivores, feral pigs (Sus scrofa) are responsible for wholesale adverse effects on islands. Here, we report on the eradication of feral pigs from Santiago Island in the Galápagos Archipelago, Ecuador, which is the largest insular pig removal to date. Using a combination of ground hunting and poisoning, over 18,000 pigs were removed during this 30-year eradication campaign. A sustained effort, an effective poisoning campaign concurrent with the hunting program, access to animals by cutting more trails, and an intensive monitoring program all proved critical to the successful eradication. While low and fluctuating control efforts may help protect select native species, current eradication methods, limited conservation funds, and the potential negative non-target impacts of sustained control efforts all favor an intense eradication effort, rather than a sustained control program. The successful removal of pigs from Santiago Island sets a new precedent, nearly doubling the current size of a successful eradication, and is leading to more ambitious projects. However, now we must turn toward increasing eradication efficiency. Given limited conservation funds, we can no longer afford to spend decades removing introduced mammals from islands.     

Evaluating alternative rodenticides for island conservation: roof rat eradication from the San Jorge Islands, Mexico

Introduced commensal rats (Rattus spp.) are a major contributor to the extinction and endangerment of island plants and animals. The use of the toxin brodifacoum to completely eradicate rats from islands is a powerful conservation tool. However, brodifacoum is toxic to animals other than rats and on some islands its use may not be feasible without prohibitively expensive mitigation. As part of a regional conservation program, we experimentally tested brodifacoum and two less toxic rodenticides, diphacinone and cholecalciferol, in eradicating Rattus rattus from three small islands in the northern Gulf of California, Mexico. All three rodenticides were successful in eradicating rats, suggesting that the less toxic diphacinone and cholecalciferol may be useful alternatives to brodifacoum for some island eradication programs. However, the choice of rodenticide must be balanced between efficacy and the risks to non-target species. Applied field research is needed on less toxic rodenticides, as well as improving palatability of baits. This may prove invaluable in preventing extinctions and in restoring larger and more diverse island ecosystems.     

Assessing the utility of indicator groups for the conservation of South American terrestrial mammals

Because data on the distribution of most species are limited, prioritizing sites for conservation requires the use of indicator groups to represent overall diversity. The purpose of this study is to assess the utility of different subsets of the South American mammal fauna in representing the overall diversity of South American terrestrial mammals, percentage of endangered and restricted-range species, and the percentage of monotypic genera. Particularly, I assess the effectiveness and efficiency of explicitly selected indicator groups at two spatial scales - continental South America and the country of Brazil. Results show that all indicator groups were more effective than a random selection of cells. However, when compared with sets of randomly selected species, only one indicator group outperformed these sets. An indicator group composed of geographically rare species was more effective and efficient at both spatial scales, protecting a higher percentage of the total number of species, as well as higher percentages of endangered and rare species, and total number of monotypic genera.     

哺乳动物体细胞克隆的研究与应用

通过查阅研究1997年以来国内外对哺乳动物体细胞克隆技术的研究文献,综述了哺乳动物体细胞克隆技术的发展历史、研究现状、影响因素及存在问题,并对其应用前景进行了探讨。