Enemies and turncoats: bovine tuberculosis exposes pathogenic potential of Rift Valley fever virus in a common host,African buffalo (Syncerus caffer)

The ubiquity and importance of parasite co-infections in populations of free-living animals is beginning to be recognized, but few studies have demonstrated differential fitness effects of single infection versus co-infection in free-living populations. We investigated interactions between the emerging bacterial disease bovine tuberculosis (BTB) and the previously existing viral disease Rift Valley fever (RVF) in a competent reservoir host, African buffalo, combining data from a natural outbreak of RVF in captive buffalo at a buffalo breeding facility in 2008 with data collected from a neighbouring free-living herd of African buffalo in Kruger National Park. RVF infection was twice as likely in individual BTB+ buffalo as in BTB− buffalo, which, according to a mathematical model, may increase RVF outbreak size at the population level. In addition, co-infection was associated with a far higher rate of fetal abortion than other infection states. Immune interactions between BTB and RVF may underlie both of these interactions, since animals with BTB had decreased innate immunity and increased pro-inflammatory immune responses. This study is one of the first to demonstrate how the consequences of emerging infections extend beyond direct effects on host health, potentially altering the dynamics and fitness effects of infectious diseases that had previously existed in the ecosystem on free-ranging wildlife populations.     

Deleterious effects by mosquitofish (Gambusia affinis) on the endangered fire salamander (Salamandra infraimmaculata)

Invasive fishes, via competition and predation, may be an important factor in endangering populations of amphibians and other aquatic fauna. The mosquitofish, Gambusia affinis , commonly stocked into amphibian breeding sites for mosquito control worldwide, has recently been found in some breeding sites of the endangered fire salamander Salamandra infraimmaculata in northern Israel. A comparison of Salamandra larvae in natural pools varying in Gambusia densities suggested that Gambusia negatively affects Salamandra by causing damage to its appendages, in particular, its tailfin (as manifested in a smaller tail:body ratio). Comparison of the same pool before and after mosquitofish introduction suggested strong negative effects on larval performance and number of emerging metamorphs. To explicitly test the hypothesis that Gambusia negatively affects Salamandra larval development, growth and survival, we conducted a replicated outdoor mesocosm experiment. In this experiment, we also tested how habitat structural complexity, in the form of radiating cords simulating artificial vegetation, might mediate damage caused by Gambusia . We used a two-by-two factorial design: the presence or absence of increased structural complexity crossed with the presence or absence of mosquitofish. After a short period, mosquitofish strongly reduced larval wet weight and survival, and increased body damage in the form of a reduced larval tail:body ratio and partially missing gills and limbs. No Salamandra larvae exposed to mosquitofish survived to metamorphosis in either habitat type. We conclude that Gambusia strongly and negatively affects Salamandra larvae and that the introduction of Gambusia into sites containing Salamandra is inconsistent with the goal of preserving this endangered urodele.     

Origin of the parasites of an invading species,the Australian cane toad (Bufo marinus): are the lungworms Australian or American?

Phylogeographical analyses that identify the geographical origin of parasites in invading species can clarify the parasites' potential for biological control of the invader and the risks posed by the parasite to native species. Our data on nuclear and mitochondrial genetic sequences show that the nematode lungworms (Rhabdias spp.) in invasive Australian populations of cane toads (Bufo marinus) are Rhabdias pseudosphaerocephala, a South American species. We did not find this lungworm species in any Australian frogs sympatric with cane toads, suggesting that the parasite does not attack Australian frogs and hence may offer potential as a biocontrol agent of the toad.     

中国、日本、加拿大及EPPO植物检疫性菌物名录的比较分析

【目的】分析中国、日本、加拿大及欧洲和地中海植物保护组织(European and Mediterranean Plant Protection Organization, EPPO)现行植物检疫性有害生物名录,以期为我国科学合理制定检疫性菌物名录提供参考。【方法】结合世界三大菌物名称注册库Fungal Name、Mycobank及Index Fungrum信息,对上述名录中检疫性菌物学名、种类、数量等信息进行比较研究。【结果】4个国家或地区的名录共涉及检疫性菌物218种,分布在2界4门30目61科114属中。其中,中国有82属130种,日本有43属61种,加拿大有30属41种,EPPO有41属67种。在检疫性菌物涉及类群方面,4个国家或地区各类群所占比例不同,4个国家或地区名录中子囊菌门占比均为最高,中国和日本名录中卵菌门和担子菌门占比相近,加拿大卵菌门占比较高,EPPO担子菌门占比较高。4个国家或地区独有的检疫性菌物情况分别为中国77种,日本34种,加拿大22种,EPPO 25种。4个国家或地区共有的检疫性菌物有5种,分别是栎枯萎病菌、栎树猝死病菌、马铃薯癌肿病菌、小麦印度腥黑穗病菌和马铃薯黑粉病菌。【结论】由于菌物分类学的快速发展,许多检疫性菌物的分类地位已经发生变化,4个国家或地区中,我国检疫性菌物名录与国际公认现用学名不一致情况最为明显,我国检疫性菌物名录亟待修订完善。     

Ancient DNA applications for wildlife conservation

Ancient DNA analyses of historical, archaeological and paleontological remains can contribute important information for the conservation of populations and species that cannot be obtained any other way. In addition to ancient DNA analyses involving a single or few individuals, population level studies are now possible. Biases inherent in estimating population parameters and history from modern genetic diversity are exaggerated when populations are small or have been heavily impacted by recent events, as is common for many endangered species. Going directly back in time to study past populations removes many of the assumptions that undermine conclusions based only on recent populations. Accurate characterization of historic population size, levels of gene flow and relationships with other populations are fundamental to developing appropriate conservation and management plans. The incorporation of ancient DNA into conservation genetics holds a lot of potential, if it is employed responsibly.     

美国对入侵种的管理对策

外来种入侵是产生当前世界生物多样性危机的重要原因之一。目前外来种入侵问题已经引起人们的普遍关注。1999年2月美国联邦政府发布总统令,号召联邦政府机构执行人员防止外来入侵种所造成的严重环境威胁,指示有关职能部门行使职权阻止引入入侵种并且恢复本地种。总统令指示建立一个入侵物种理事会,并就理事会、联邦机构的职责做了相应界定。美国农业部等部门支持的入侵植物管理国家策略项目,提出了针对入侵种的三项国家目标一入侵种的预防、控制和本地种的恢复。国家管理策略的制定不同层次的人们提供了合作、教育和研究的机遇。美国政府部门以及有关社会团体已经就外来种入侵危害防范积极展开行动,包括制定标准防止入侵种进入,控制、根除入侵种,向民众进行有关外来种入侵的教育,增加财政年度预算等等。