Locally asymmetric introgressions between subspecies suggest circular range expansion at the Antirrhinum majus global scale

Assessing processes of geographic expansion in contact zones is a crucial step towards an accurate prediction of the evolution of species genetic diversity. The geographic distribution of cytonuclear discordance often reflects genetic introgression patterns across a species geographic range. Antirrhinum majus pseudomajus and A. m. striatum are two interfertile subspecies that occupy nonoverlapping areas but enter in contact in many locations at the margin of their geographic distribution. We found that genetic introgression between both subspecies was asymmetric at the local scale and geographically oriented in opposite directions at both ends of their contact zone perimeter in the Pyrenees. Our results suggest that the geographic expansion of A. majus subspecies was circular around the perimeter of their contact zone and pinpoint the need to integrate different spatial scales to unravel complex patterns of species geographic expansion.     

Open resource metagenomics: a model for sharing metagenomic libraries

Both sequence-based and activity-based exploitation of environmental DNA have provided unprecedented access to the genomic content of cultivated and uncultivated microorganisms. Although researchers deposit microbial strains in culture collections and DNA sequences in databases, activity-based metagenomic studies typically only publish sequences from the hits retrieved from specific screens. Physical metagenomic libraries, conceptually similar to entire sequence datasets, are usually not straightforward to obtain by interested parties subsequent to publication. In order to facilitate unrestricted distribution of metagenomic libraries, we propose the adoption of open resource metagenomics, in line with the trend towards open access publishing, and similar to culture- and mutant-strain collections that have been the backbone of traditional microbiology and microbial genetics. The concept of open resource metagenomics includes preparation of physical DNA libraries, preferably in versatile vectors that facilitate screening in a diversity of host organisms, and pooling of clones so that single aliquots containing complete libraries can be easily distributed upon request. Database deposition of associated metadata and sequence data for each library provides researchers with information to select the most appropriate libraries for further research projects. As a starting point, we have established the Canadian MetaMicroBiome Library (CM²BL [1]). The CM²BL is a publicly accessible collection of cosmid libraries containing environmental DNA from soils collected from across Canada, spanning multiple biomes. The libraries were constructed such that the cloned DNA can be easily transferred to Gateway® compliant vectors, facilitating functional screening in virtually any surrogate microbial host for which there are available plasmid vectors. The libraries, which we are placing in the public domain, will be distributed upon request without restriction to members of both the academic research community and industry. This article invites the scientific community to adopt this philosophy of open resource metagenomics to extend the utility of functional metagenomics beyond initial publication, circumventing the need to start from scratch with each new research project.     

Factors affecting the daily rhythm of body temperature of captive mouse lemurs (<Emphasis Type="Italic">Microcebus murinus</Emphasis>)

Microcebus murinus, a small nocturnal Malagasy primate, exhibits adaptive energy-saving strategies such as daily hypothermia and gregarious patterns during diurnal rest. To determine whether ambient temperature (T_a), food restriction and nest sharing can modify the daily body temperature (T_b) rhythm, T_b was recorded by telemetry during winter in six males exposed to different ambient temperatures (T_a=25, 20, 15°C) and/or to a total food restriction for 3 days depending on social condition (isolated versus pair-grouped). At 25°C, the daily rhythm of T_b was characterized by high T_b values during the night and lower values during the day. Exposure to cold significantly decreased minimal T_b values and lengthened the daily hypothermia. Under food restriction, minimal T_b values were also markedly lowered. The combination of food restriction and cold induced further increases in duration and depth of torpor bouts, minimal T_b reaching a level just above T_a. Although it influenced daily hypothermia less than environmental factors, nest sharing modified effects of cold and food restriction previously observed by lengthening duration of torpor but without increasing its depth. In response to external conditions, mouse lemurs may thus adjust their energy expenditures through daily modifications of both the duration and the depth of torpor.     

Vicissitudes of benefit sharing of crop genetic resources: downstream and upstream

In this article, we will first give a historic overview of the concept of benefit sharing and its appearance in official agreements, particularly with respect to crop genetic resources. It will become clear that, at present, benefit sharing is primarily considered as an instrument of compensation or exchange, and thus refers to commutative justice. However, we believe that such a narrow interpretation of benefit sharing disregards, and even undermines, much of its (historical) content and potency, especially where crop genetic resources are concerned. We argue that benefit sharing should not be based merely on commutative justice but rather on a broader model that is also grounded in the concept of distributive justice. This has repercussions for the application of benefit sharing, which we try to clarify by distinguishing between downstream and upstream benefit sharing. Upstream benefit sharing is not so much inspired by compensation for actions done, or the distribution downstream of benefits developed, but by the idea of shared decision-making on the research and development of resources fundamental to human welfare. Going upstream in the research process of crop genetic resources, and determining research agendas and improving crops according to the needs of the poor, benefit sharing may well be a tool to contribute to world food security and global justice. We concretize our ideas on upstream benefit sharing by introducing a set of criteria that determine the success of consultations on agricultural research agenda setting.     

Trampling, defoliation and physiological integration affect growth, morphological and mechanical properties of a root-suckering clonal tree

Background and Aims

Grazing is a complex process involving the simultaneous occurrence of both trampling and defoliation. Clonal plants are a common feature of heavily grazed ecosystems where large herbivores inflict the simultaneous pressures of trampling and defoliation on the vegetation. We test the hypothesis that physiological integration (resource sharing between interconnected ramets) may help plants to deal with the interactive effects of trampling and defoliation.

Methods

In a field study, small and large ramets of the root-suckering clonal tree Populus simonii were subjected to two levels of trampling and defoliation, while connected or disconnected to other ramets. Plant responses were quantified via survival, growth, morphological and stem mechanical traits.

Key Results

Disconnection and trampling increased mortality, especially in small ramets. Trampling increased stem length, basal diameter, fibrous root mass, stem stiffness and resistance to deflection in connected ramets, but decreased them in disconnected ones. Trampling decreased vertical height more in disconnected than in connected ramets, and reduced stem mass in disconnected ramets but not in connected ramets. Defoliation reduced basal diameter, leaf mass, stem mass and leaf area ratio, but did not interact with trampling or disconnection.

Conclusions

Although clonal integration did not influence defoliation response, it did alleviate the effects of trampling. We suggest that by facilitating resource transport between ramets, clonal integration compensates for trampling-induced damage to fine roots.     

The impact of multiple biogeographic barriers and hybridization on species-level differentiation

• Premise of the study: The glacial cycles of the Quaternary did not impact Australia in the same way as Europe and North America. Here we investigate the history of population isolation, species differentiation, and hybridization in the southeastern Australian landscape, using five species of Lomatia (Proteaceae). We use a chloroplast DNA phylogeography to assess chloroplast haplotype (chlorotype) sharing among these species and whether species with shared distributions have been affected by shared biogeographic barriers. • Methods: We used six chloroplast DNA simple sequence repeats (cpSSR) across five species of Lomatia, sampled across their entire distributional range in southeastern Australia. Resulting size data were combined, presented as a network, and visualized on a map. Biogeographical barriers were tested using AMOVA. To explore hypotheses of chlorotype origin, we converted the network into a cladogram and reconciled with all possible species trees using parsimony-based tree mapping. • Key results: Some chlorotypes were shared across multiple species of Lomatia in the study, including between morphologically differentiated species. Chlorotypes were either widespread in distribution or geographically restricted to specific regions. Biogeographical structure was identified across the range of Lomatia. The most parsimonious reconciled tree incorporated horizontal transfer of chlorotypes. • Conclusions: Lomatia shows evidence of both incomplete lineage sorting and extensive hybridization between co-occurring species. Although the species in the study appear to have responded to a number of biogeographic barriers to varying degrees, our findings identified the Hunter River Valley as the most important long-term biogeographic barrier for the genus in southeastern Australia.     

Social tolerance in a despotic primate: co-feeding between consortship partners in rhesus macaques

Food sharing among nonkin-one of the most fascinating cooperative behaviors in humans-is not widespread in nonhuman primates. Over the past few years, a large body of work has investigated the contexts in which primates cooperate and share food with unrelated individuals. This work has successfully demonstrated that species-specific differences in temperament constrain the extent to which food sharing emerges in experimental situations, with despotic species being less likely to share food than tolerant ones. However, little experimental work has examined the contexts that promote food sharing and cooperation within a species. Here, we examine whether one salient reproductive context-the consortship dyad-can allow the necessary social tolerance for co-feeding to emerge in an extremely despotic species, the rhesus macaque (Macaca mulatta). We gave naturally formed male-female rhesus macaque pairs access to a monopolizable food site in the free-ranging population at Cayo Santiago, Puerto Rico. Using this method, we were able to show that tolerated co-feeding between unrelated adults can take place in this despotic species. Specifically, our results show that consort pairs co-fed at the experimental food site more than nonconsort control pairs, leading females to obtain more food in this context. These results suggest that co-feeding is possible even in the most despotic of primate species, but perhaps only in contexts that specifically promote the necessary social tolerance. Researchers might profit from exploring whether other kinds of within-species contexts could also generate cooperative behaviors.     

农作物种质资源调查数据标准制定与共享

系统提取并分析了农作物种质资源普查数据、调查数据、评价数据和保存数据等数据信息,采用基于数据元技术方法制定了农作物种质资源调查数据标准和数据元目录;定义了种质资源调查数据集以及对象和属性的映射关系;给出了基于XML数据标准存储及交换策略。标准的制定使农作物种质资源调查在"数据层"上达到统一,规范了数据库构建,促进了农作物种质资源调查数据的整合和共享。     

Care of HIV-infected patients in China

Compared with high infection areas of the world, the total HIV infection rate in China is relatively low. Nonetheless,because of China‘s vast territory and large population, the potential infection risk must be taken seriously. In the next few years, needle sharing among injection drug users will remain the most common route of transmission for the HIV/AIDS epidemic in China. Unprotected sex is gradually becoming a major route of transmission. China began to implement HAART in 1999 according to international standards. Prior to 2003, there were only about 150 HIV/AIDS patients were treated with HAART in some clinical trials and about 100 HIV/AIDS patients were treated by private sources.Results of those treatments are the scientific basis for development of the therapeutic strategies in China. In March of 2003, the Chinese government initiated China CARES program. In November of 2003, the Chinese Ministry of Health announced a national policy of free ARV treatment to all HIV Chinese citizens who were in poverty and required ARV therapy. There are total of 19,456 HIV/AIDS patients received free ARV drugs to date in 159 regions and 441 towns.Current challenges are how to follow-up and evaluate those patients in the clinical settings. The longer the therapy is postponed, the more side effects and the higher probability of drug resistance are going to occur. It remains unclear,therefore, when HAART regimen should be started in the HIV/AIDS population in China.