Mitochondrial DNA variation analysis suggests extreme low genetic diversity in Guizhou snub-nosed monkeys （Rhinopithecus brelichi）

Guizhou snub-nosed monkey (Rhinopithecus brelichi) is a unique, endangered primate in China, mainly distributed in Fanjing Mountain National Natural Reserve, Guizhou Province, in an area of 275 km2. Recently, habitat loss and fragmentation have caused population isolation. To assess genetic diversity within this species and its population structure, we sequenced 400 bp of the hypervariable I segment from the mitochondrial DNA control region for 128 individuals. Only one haplotype was identified from these individuals. Compared with other primate species, R. brelichi can be regarded as a species with very low genetic diversity, which further adds to the conservation concern.     

多辐溲疏居群过氧化物酶同工酶分化的研究

运用聚丙烯酰胺凝胶电泳，测试了采自四川南川县金佛山不同生境的多辐溲疏５个居群５０株个体的过氧化物酶同工酶，对酶谱带位置进行了二态编码，然后采用Ｒｏｇｅｒｓ－Ｔａｎｉｍｏｔｏ，Ｓｏｋａｌ－Ｍｉｃｈ－ｅｎｅｒ，Ｓｏｋａｌ－Ｓｎｅａｔｈ，Ｊａｃｃａｒｄ等结合系数用组平均法（ＵＰＧＭＡ）对各谱带位置进行了聚类分析．结果表明，相同生境同一居群内的个体间表现出较大的遗传同质性，而来源于不同生境的不同居群个体间却呈现出较大的遗传趋异性；同时，５个居群不但具有许多共同谱带，而且整体相聚的结合系数大多超过０．５，这表明５个居群在很早以前可能是属于同一大居群，在长期进化过程中，由于微生境的地理与气候因子选择，使得多辐溲疏现仅在金佛山海拔６００～１２００ｍ的约ｋｍ２范围内呈岛状分布；又由于其特殊的繁殖方式——居群内个体虽能杂交，但因该种仅能正常开花传粉，大部分种子败育，使得居群内个体遗传变异性不能通过有性生殖方式固定下来，仅能通过营养繁殖方式繁殖后代，而正是营养繁殖导致了居群内较大遗传同质性以及居群间的遗传趋异性．在整个进化过程中生境只不过是对那些遗传变异起到了选择固定作用     

Nurtured to follow the crowd: A twin study on conformity

Why are some of us easily affected by the majority’s action whereas others frequently make unique choices? In this behavioral genetic study on conformity,we designed a social episode to investigate the genetic and environmental origin of individual differences in conforming behavior during psychosocial development.Specifically,107 monozygotic(MZ) and 74 dizygotic(DZ) twin pairs(age 7-19) were asked to choose a pen from a group of pens either with the majority color or with the minority color.We found that the resemblance between MZ twins in selecting the pen with the majority color was not significantly higher than that between DZ twins,suggesting that individual differences in conformity are due almost exclusively to the environment.Moreover,biometric model fitting revealed that the shared environmental component played a sizable role in shaping individuals’ conforming behavior,and the influence increased with age(from 16% to 26%).Taken together,our study suggests that the common family and cultural environment has important ramifications for conformity.     

Advances in research of mammalian vomeronasal pheromone perception and genetic components unique to vomeronasal signal transduction pathway

The recognition and perception of chemical signals from environments are very important for the survival of organisms. In mammals, general chemical signals are mainly detected by the main olfactory system (MOS), while pheromones are primarily perceived by the vomeronasal system (VNS). Pheromones are chemicals released and recognized by individuals within the same species, which then induce physiological and behavioral changes in social and sexual activities. In this review, we focus on the recent advances on research in mammalian vomeronasal pheromone perception and those genetic components unique to vomeronasal signal transduction pathway, including vomeronasal receptor V1R and V2R gene families as well as transient receptor potential channel 2 gene (TRPC2), trying to shed light on further study of the molecular mechanisms of mammalian pheromone perception.     

Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico.

Concerns have been raised about the potential effects of transgenic introductions on the genetic diversity of crop landraces and wild relatives in areas of crop origin and diversification, as this diversity is considered essential for global food security. Direct effects on non-target species, and the possibility of unintentionally transferring traits of ecological relevance onto landraces and wild relatives have also been sources of concern. The degree of genetic connectivity between industrial crops and their progenitors in landraces and wild relatives is a principal determinant of the evolutionary history of crops and agroecosystems throughout the world. Recent introductions of transgenic DNA constructs into agricultural fields provide unique markers to measure such connectivity. For these reasons, the detection of transgenic DNA in crop landraces is of critical importance. Here we report the presence of introgressed transgenic DNA constructs in native maize landraces grown in remote mountains in Oaxaca, Mexico, part of the Mesoamerican centre of origin and diversification of this crop.     

试论汉字的多重品格

对汉字的研究不能再停留于形、音、义的表层，而需要从哲学和文化学的角度进行深入的考察。我们发现，汉字既有着与其他文字相同的符号性特点，还有着神圣性、历史性、审美性、生态性、价值性等独特属性，研究这些独特属性，对于九年制义务教育阶段学生的识字、写字教学有着重要的意义。     

When the American sea sturgeon swam east

The two species of Atlantic sea sturgeon on either shore of the North Atlantic, Acipenser sturio in Europe and A. oxyrinchus in North America, probably diverged with the closure of the Tethys Sea and the onset of the North Atlantic Gyre 15-20 million years ago, and contact between them was then presumably precluded by geographic distance. Here we present genetic, morphological and archaeological evidence indicating that the North American sturgeon colonized the Baltic during the Middle Ages and replaced the native sturgeon there, before recently becoming extinct itself in Europe as a result of human activities. In addition to representing a unique transatlantic colonization event by a fish that swims upriver to spawn, our findings have important implications for projects aimed at restocking Baltic waters with the European sturgeon.     

Parallel evolution of domesticated Caenorhabditis species targets pheromone receptor genes

Evolution can follow predictable genetic trajectories, indicating that discrete environmental shifts can select for reproducible genetic changes. Conspecific individuals are an important feature of an animal's environment, and a potential source of selective pressures. Here we show that adaptation of two Caenorhabditis species to growth at high density, a feature common to domestic environments, occurs by reproducible genetic changes to pheromone receptor genes. Chemical communication through pheromones that accumulate during high-density growth causes young nematode larvae to enter the long-lived but non-reproductive dauer stage. Two strains of Caenorhabditis elegans grown at high density have independently acquired multigenic resistance to pheromone-induced dauer formation. In each strain, resistance to the pheromone ascaroside C3 results from a deletion that disrupts the adjacent chemoreceptor genes serpentine receptor class g (srg)-36 and -37. Through misexpression experiments, we show that these genes encode redundant G-protein-coupled receptors for ascaroside C3. Multigenic resistance to dauer formation has also arisen in high-density cultures of a different nematode species, Caenorhabditis briggsae, resulting in part from deletion of an srg gene paralogous to srg-36 and srg-37. These results demonstrate rapid remodelling of the chemoreceptor repertoire as an adaptation to specific environments, and indicate that parallel changes to a common genetic substrate can affect life-history traits across species.     

濒危植物华山新麦草(Psathyrostachys huashanica)的遗传多样性及其保护

筛选的12条ISSR引物，对采集于陕西华山3个自然居群、20个亚居群的150个华山新麦草(Psathyrostachys huashanica Keng ex Guo)个体的遗传多样性进行了分析．发现华山新麦草样本ISSR产物的多态位点比率(P)为96．8％；每个位点的平均有效等位基因数(Ae)为1．411；居群的预期杂合度(He)为0．251，大于一般风媒异交植物的平均值0．148；居群的香农多样性指数(I)为0．391；这些结果表明华山新麦草在居群水平上有相对较高的遗传多样性．亚居群间的基因分化系数(GST)为0．304，表明大部分(约为70％)的遗传变异均存在于亚居群内．同时亚居群间具有一定频率的基因流，其遗传相似性也较高，变化范围为0．796～0．974(平均为0．903)．根据上述结果推断，华山新麦草的濒危不是因为遗传多样性稀有，而是由于它对特殊生态环境的要求影响了它的扩散而仅分布于华山这一狭小范围．因此，只要能够保证目前华山的生态环境不被进一步破坏，华山新麦草就能得到很好的保护而不会因种内遗传多样性降低而灭绝．     

Microsatellite polymorphisms of Sichuan golden monkeys

Previous study using protein electrophoresis shows no polymorphism in 44 nuclear loci of Sichuan golden monkey （Rhinopithecus roxellana）, which limits our understandings of its population genetic patterns in the nuclear genome. In order to obtain sufficient information, we scanned 14 microsatellite loci in a sample of 32 individuals from its three major habitats （Minshan, Qinling and Shennongjia）. A considerable amount of polymorphisms were detected. The average heterozygosities in the local populations were all above 0.5. The differentiations among local populations were significant. There was evidence of geneflow among subpopulations, but geneflow between Qinling and Shennongjia local populations was the weakest. Minshan and Qinling populations might have gone through recent bottlenecks. The estimation of the ratio of the effective population sizes among local populations was close to that from census sizes. Comparisons to available mitochondria data suggested that R. roxellana＇s social structures played an important role in shaping its population genetic patterns. Our study showed that the polymorphism level of R. roxellana was no higher than other endangered species; therefore, measures should be taken to preserve genetic diversity of this species.     

Deciphering the evolution and metabolism of an anammox bacterium from a community genome

Anaerobic ammonium oxidation (anammox) has become a main focus in oceanography and wastewater treatment. It is also the nitrogen cycle's major remaining biochemical enigma. Among its features, the occurrence of hydrazine as a free intermediate of catabolism, the biosynthesis of ladderane lipids and the role of cytoplasm differentiation are unique in biology. Here we use environmental genomics--the reconstruction of genomic data directly from the environment--to assemble the genome of the uncultured anammox bacterium Kuenenia stuttgartiensis from a complex bioreactor community. The genome data illuminate the evolutionary history of the Planctomycetes and allow us to expose the genetic blueprint of the organism's special properties. Most significantly, we identified candidate genes responsible for ladderane biosynthesis and biological hydrazine metabolism, and discovered unexpected metabolic versatility.     

基于色木枫转录组数据的核低拷贝基因引物开发

基于色木枫的转录组数据初步设计166对引物,并根据琼脂糖凝胶电泳与Sanger测序结果筛选出其中的26对核低拷贝基因引物．在东亚63个种群的182个个体中大批量扩增所开发引物,单倍型多样性范围为0.45~0.97,核苷酸多样性为(1.90~18.03)×10?3;9~15对引物可在金钱槭、茶条槭、青榨槭和鸡爪槭中扩增;STRUCTURE聚类结果与之前核微卫星研究结果类似,且展示了更多的谱系地理结构,结果表明引物多态性高、拓展性强、具有可靠性．本研究的转录组数据为槭属的研究提供重要遗传信息,所用方法被证明可以有效开发大量核低拷贝基因引物,已开发出的26对引物将为色木枫的进化历史和槭属系统发育研究提供丰富有效的分子标记．      

On the origin of species by sympatric speciation.

Understanding speciation is a fundamental biological problem. It is believed that many species originated through allopatric divergence, where new species arise from geographically isolated populations of the same ancestral species. In contrast, the possibility of sympatric speciation (in which new species arise without geographical isolation) has often been dismissed, partly because of theoretical difficulties. Most previous models analysing sympatric speciation concentrated on particular aspects of the problem while neglecting others. Here we present a model that integrates a novel combination of different features and show that sympatric speciation is a likely outcome of competition for resources. We use multilocus genetics to describe sexual reproduction in an individual-based model, and we consider the evolution of assortative mating (where individuals mate preferentially with like individuals) depending either on an ecological character affecting resource use or on a selectively neutral marker trait. In both cases, evolution of assortative mating often leads to reproductive isolation between ecologically diverging subpopulations. When assortative mating depends on a marker trait, and is therefore not directly linked to resource competition, speciation occurs when genetic drift breaks the linkage equilibrium between the marker and the ecological trait. Our theory conforms well with mounting empirical evidence for the sympatric origin of many species.     

Genetic similarity between mates and extra-pair parentage in three species of shorebirds

Matings between close relatives often reduce the fitness of offspring, probably because homozygosity leads to the expression of recessive deleterious alleles. Studies of several animals have shown that reproductive success is lower when genetic similarity between parents is high, and that survival and other measures of fitness increase with individual levels of genetic diversity. These studies indicate that natural selection may favour the avoidance of matings with genetically similar individuals. But constraints on social mate choice, such as a lack of alternatives, can lead to pairing with genetically similar mates. In such cases, it has been suggested that females may seek extra-pair copulations with less related males, but the evidence is weak or lacking. Here we report a strong positive relationship between the genetic similarity of social pair members and the occurrence of extra-pair paternity and maternity ('quasi-parasitism') in three species of shorebirds. We propose that extra-pair parentage may represent adaptive behavioural strategies to avoid the negative effects of pairing with a genetically similar mate.     

阿尔泰两河源物种多样性及其保护

阿尔泰两河源区生境多样性形成了新疆地区独特的、具有潜在经济和生态价值的遗传基因,多种动植物已被列为优先保护物种和中国濒危重点保护植物,其物种多样性在新疆乃至全国占有相当重要地位.在物种多样性保护和研究方面,对重要的动植物资源进行迁地保护和专属引种研究.物种多样性迁地保护、种群分布地生态系统保护和自然景观多样性保护对古老特有成分、受威胁的动植物种类和具有重要经济潜力的物种资源具有重大意义.     

Genes mirror geography within Europe

Understanding the genetic structure of human populations is of fundamental interest to medical, forensic and anthropological sciences. Advances in high-throughput genotyping technology have markedly improved our understanding of global patterns of human genetic variation and suggest the potential to use large samples to uncover variation among closely spaced populations. Here we characterize genetic variation in a sample of 3,000 European individuals genotyped at over half a million variable DNA sites in the human genome. Despite low average levels of genetic differentiation among Europeans, we find a close correspondence between genetic and geographic distances; indeed, a geographical map of Europe arises naturally as an efficient two-dimensional summary of genetic variation in Europeans. The results emphasize that when mapping the genetic basis of a disease phenotype, spurious associations can arise if genetic structure is not properly accounted for. In addition, the results are relevant to the prospects of genetic ancestry testing; an individual's DNA can be used to infer their geographic origin with surprising accuracy-often to within a few hundred kilometres.     

增强自主创新能力与古人精神信念的局限性

中国古人的精神世界气宇轩昂卓然不凡，它是历代有识之士的精神营养，也是今天知识分子投身科技创新的精神动力。我们也应该看到中国古人精神信念的不足与局限。这种消极方面在今天仍值得警惕。古人精神信念中的不足，首先是追求信念过于关注现实，因而社会行为中缺少了探索客观真理的动机；其次是人生信念过于世俗，因而社会行为中缺少了超越性追求；第三是处世信念过于圆滑，因而思想和行为中缺少了独立性。这三个不足，曾妨碍了中国古代的科技发展。以史为镜，方能明得失、知兴替、与时俱进。     

无柄醉鱼草与大叶醉鱼草的遗传多样性解析

无柄醉鱼草(Buddleja sessilifolia)是狭域分布的极小种群野生植物(Plant Species with Extremely Small Populations, PSESP),大叶醉鱼草(B.davidii)则是广布种,二者亲缘关系较近,且同为四倍体。通过比较濒危物种与近缘广布种的遗传多样性,可以了解濒危物种的演化历史,为制定保护策略提供理论依据。本研究通过简单重复序列(Simple Sequence Repeats, SSR)分子标记对无柄醉鱼草5个居群(126个个体)和大叶醉鱼草14个居群(206个个体)进行遗传多样性和遗传结构解析,并提出对无柄醉鱼草的保护建议。结果表明,无柄醉鱼草和大叶醉鱼草各居群的期望杂合度(He)平均值分别为0.606、0.775,Shannon′s多样性指数(I)平均值分别为1.162、1.729,两个物种均具有较高的遗传多样性,但广布种大叶醉鱼草遗传多样性水平高于狭域种无柄醉鱼草;无柄醉鱼草和大叶醉鱼草遗传分化系数(F_ST)分别为0.043和0.024,两个物种居群间遗传分化程度均较低。遗传结构分析结果表明,无柄...     

西南联大对我国创建世界一流大学的启示

西南联大堪称我国教育史上的一流大学,也是中国现代高等教育史上的一株奇葩,其光华为世界所瞩目,它的成功办学经验对于当前我国创建世界一流大学的启示主要有：独特的办学理念是创建一流大学的灵魂;科学的管理制度是创建一流大学的保障;杰出的大学校长是创建一流大学的关键;优秀的师资队伍是创建一流大学的前提;有力的政策支持是创建一流大学的助推器。     

Estimating genetic diversity and sampling strategy for a wild soybean （Glycine soja） population based on different molecular markers

With the rapid development of the global economy and continued increase in world population, natural environments face serious deterioration and change, which has led to the extinction or severe endangerment of many plant species including important crops…