遗传物质的发现者之一——麦卡锡

1944年,3位科学家艾弗里、麦卡锡和麦克劳德在DNA遗传本质方面的发现是20世纪最重要的发现之一,这个发现打开了生物学革命的大门,从而改变了人类对自然界的看法,这项研究还为1953年沃森和克里克DNA双螺旋结构的发现奠定了坚实的基础,但不幸的是3位科学家都未曾荣获诺贝尔奖.通过介绍麦克林·麦卡锡的科学研究,从而对这项发现的基本状况有一个基本的了解.     

苏联猛犸象的研究

猛犸象(Elephas primigenius)是最著名的动物化石之一。在欧洲,西伯利亚,中国北部以及其他区域内的许多地方,都曾发现过大批这种动物的遗体,而且它们的庞大的躯体与奇特的形状早就吸引了人们的注意。此外,在亚洲及欧洲的冻土带内,曾发现过这种动物的,连皮,肉和毛都保存着的完整的尸体。古代极北地区的居民,当他们发现了这些由于海岸崩裂而从地下深处露出来的尸体后,曾企图寻求关于这些奇怪动物的外貌的解释。在耶库     

c-Cbl介导了hSef的泛素化和降解

Sef(similar expression to fgf genes)作为FGF信号通路中可诱导的拮抗分子相继在斑马鱼,小鼠,和人类中被鉴定出来,并进行了相应的功能研究.目前对于Sef蛋白本身稳定性的研究还未见报道.对c-Cbl对Sef稳定性的影响进行了研究.免疫荧光实验表明Sef能够和c-Cbl蛋白在细胞中发生共定位,随后的免疫共沉淀实验证明Sef能够和c-Cbl发生相互作用.体内泛素化实验表明c-Cbl能够使Sef发生明显的泛素化作用.这种泛素化最终导致了Sef本身的剂量依赖性的降解.针对c-Cbl的siRNA表达也使Sef稳定细胞系的表达水平得到恢复.结果表明,c-Cbl对Sef的泛素化及降解可能作为一种调控拮抗因子的蛋白质水平从而最终调节信号通路的一种机制.     

远古人类的狩猎武器

当你走进中国科学院古脊椎动物与古人类研究所内中国古动物馆的树华古人类馆,你注意到展柜里那些圆形的石头标本了吗?这就是10多万年前古人类狩猎与防身的武器——石球.与现在的手枪、步枪和机关枪的子弹和大炮的炮弹等异曲同工的是,这些远古社会古人类使用的石球是一种远距离杀伤武器.     

脑电图数据的相关性分析

目的:本文对客观记录的脑电图数据进行相关性分析,为正确理解人脑的不同局部以及局部与整体之间的相关性提供基础实验依据和理论根据,为脑电图研究的其它分析做基础分析.方法:分别对10导联电极和21导联电极的两组脑电图数据做互相关和自相关的相关性分析,得出在不同条件、事件下脑的各导联电极的自相关分析结果和左右对称导联电极的互相关分析结果,最后得出相关性值随实验条件和事件的具体变化.数据处理和统计分析采用独立设计的脑电图分析工具箱和相关性分析程序.结果:脑电图数据经过相关性分析后得到的相关图具有和脑电波相似的波形,具有周期性,时间滞后对应的标准化的相关图显示出相关性值的第一个主峰是最大的,主峰频率一般在8到13Hz的脑电波频段内;最后得到的相关性值随事件的变化而改变的结果说明实验事件对相关性的影响.结论:自相关和互相关都是随着时间滞后的增大而逐渐减小;波具有较强的相关性;相关图在从零延迟开始时间滞后所出现的第一个波峰是主峰,反应出相对较强的相关性;从大量数据的分析最后得到的相关性与事件的关系表明相关性是受事件影响的.     

高黎贡山北段东西坡种子植物区系的比较研究

高黎贡山北段的东西坡由于在降雨量和热量分配等方面存在着显著的差异,致使东西坡在植物的种类、组成及区系特征等方面表现出明显的差异.东坡记载野生种子植物152科,580属,1475种及192变种(亚种),西坡记载野生种子植物162科,659属,1804种及186变种(亚种).东西坡种子植物科、属、种的对比分析表明:1)东西坡现代种子植物区系具有相同的历史渊源,但其区系联系减弱了,东西坡区系相似性程度,依科、属、种的顺序依次递减;2)西坡现代种子植物区系比东坡具有更为深刻的热带起源烙印.就科、属、种三个水平来说,东坡的热带成分低于西坡,温带成分高于西坡.许多典型的泛热带大科在西坡比东坡有着更为丰富的种类,其中有些泛热带科分子在东坡缺乏分布,而在西坡找到了合适的驻留之地;3)西坡现代种子植物区系与东喜马拉雅植物区系的联系比东坡紧密,而东坡与高黎贡山以东的区系联系比西坡密切,由于高黎贡山山脉的阻隔,近代植物物种的东西坡交流发生了障碍;4)西坡生态地理环境比东坡更有利于物种的生存、繁衍和分化,它既是古老成分的避难所,又是孕育新生成分的摇篮.     

鸡的瞬膜

瞬膜(nictitating membrane),又称第三眼睑,是一种保护眼球、防止灰尘的结构.鸟类的瞬膜位于眼眶的前眼角,为半透明的膜,其内缘具有一种羽毛上皮,借以刷洗角膜上的灰尘.在飞行时能遮覆眼球,以避免干燥气流和灰尘对眼球的伤害.由于瞬膜在鸟类睁眼的一瞬间迅速缩回前眼角,很难拍摄到.最近费了好大的周折,终于拍到了理想的鸡瞬膜照片,现予以发表供生物学界的同行共享(友情提示:如引用请注明原作者).     

江西考古的结缘地——安义

正友情笔者从事史前考古学已40余年,让我最难忘的是与江西安义县文物爱好者胡贤钢的友情,这种友情还需从1988年讲起。当年,胡贤钢20岁,是安义县食品厂的一名工人。他勤奋好学,对历史文化有着浓厚的兴趣。他从中学历史书中掌握的一些史前学知识,来了解远古人类使用过的生产和生活工具。在休假的时候,他常常在自己家乡的丘陵和台地采集古人类使用过的工具来收藏。当时他的家庭人口多,经济拮据,但是他喜欢读书,他的父母支持他的爱好,舍得花钱给他买一些书。1988年在县的新华书店曾花一角钱,     

叶绿体基因组研究进展

作为植物细胞器的重要组成部分和光合作用的器官,叶绿体在生物进化的漫长历史中发挥了重要作用.伴随着生物技术的深入发展,人们发现叶绿体基因组结构和序列的信息在揭示物种起源、进化演变及其不同物种之间的亲缘关系等方面具有重要价值.与此同时,比核转化具有明显优势的叶绿体转化技术在遗传改良、生物制剂的生产等方面显示出巨大潜力,而叶绿体基因组结构和序列分析则是叶绿体转化的基石.基于叶绿体的这些重要作用,收集整理了有关的资料,从几个方面归纳了本领域最近的研究进展,希望能使读者对迅速发展的叶绿体基因组研究有更全面的了解,以及对叶绿体基因组在物种的进化、遗传、系统发育关系等方面的作用有更深刻的认识,同时也希望对叶绿体转化技术的研究和广泛应用产生积极作用.     

生物柴油植物桉树类叶油的开发利用

按树是我国南方地区常见的常绿树种,我们经过较长时间的调研和资料整理,认为桉树类的枝叶油与柴油的理化性质十分接近,是非常好的内燃机燃料油的代用品。而且,蒸馏按树油与绿化荒山、培育用材林矛盾不大,建设按树油基地不仅可以解决燃料油的短缺,也可培植用材林,带动地方经济的发展,增加农民收入,是一举多得的事业。     

Responses of Javan Gibbon (Hylobates moloch) Groups in Submontane Forest to Monthly Variation in Food Availability: Evidence for Variation on a Fine Spatial Scale

Primates tend to prefer specific plant foods, and primate home ranges may contain only a subset of food species present in an area. Thus, primate feeding strategies should be sensitive to the phenology of specific species encountered within the home range in addition to responding to larger scale phenomena such as seasonal changes in rainfall or temperature. We studied three groups of Javan gibbons (Hylobates moloch) in the Gunung Halimun‐Salak National Park, Indonesia from April 2008 to March 2009 and used general linear mixed models (GLMM) and a model selection procedure to investigate the effects of variation in fruit and flower availability on gibbon behavior. Preferred foods were defined as foods that are overselected relative to their abundance, while important food species were those that comprised >5% of feeding time. All important species were also preferred. Season and measurements of flower and fruit availability affected fruit‐feeding time, daily path lengths (DPL), and dietary breadth. Models that included the availability of preferred foods as independent variables generally showed better explanatory power than models that used overall fruit or flower availability. For one group, fruit and preferred fruit abundance had the strongest effects on diets and DPL in the models selected, while another group was more responsive to changes in flower availability. Temporal variation in plant part consumption was not correlated in neighboring groups. Our results suggest that fine‐scale local factors are important determinants of gibbon foraging strategies. Am. J. Primatol. 74:1154‐1167, 2012. © 2012 Wiley Periodicals, Inc.     

Phylogeography,Population Structure,and Conservation of the Javan Gibbon (<Emphasis Type="Italic">Hylobates moloch</Emphasis>)

An understanding of phylogeography and population genetics is needed for a comprehensive long-term conservation management strategy. The Javan gibbon (Hylobates moloch), an Endangered species endemic to the island of Java, has been protected since 1924 but is threatened by ongoing habitat loss, habitat degradation, and the wildlife trade. We studied the phylogeography and population genetic structure of the Javan gibbon, to define the number of Evolutionary Significant Units (ESUs) in the species, and the population genetic structure in each ESU. We sampled 47 individuals, analyzing 35 for variation in mitochondrial DNA control region, 41 for variation in 8 nuclear DNA microsatellites, and 13 for variation in 45 nuclear DNA single nucleotide polymorphisms (SNPs). We found support for two ESUs across the species range: a western ESU, extending from Ujung Kulon to Gunung Gede–Pangrango, and a central ESU, extending from Gunung Masigit–Simpang–Tilu to Gunung Slamet. Analysis of molecular variance and population structure analysis indicate significant structuring in the western ESU between Ujung Kulon and Gunung Halimun–Salak–Gede–Pangrango, and little to moderate structure in the central ESU, underscoring the importance of conserving as many populations as possible to preserve the full array of genetic diversity in this species. Our results will inform future more comprehensive population genetic surveys and the conservation genetic management of the Javan gibbon. This study demonstrates the importance of genetics when designing conservation management strategies for endangered primates.     

南方高丛蓝浆果‘南月’实生后代果实特性的变异分析

对南方高丛蓝浆果（Vaccinium corymbosum hybrids）品种‘南月’（‘Southmoon’）实生后代的单果质量、果实横径、可溶性固形物含量、单果种子数、果色、口感以及蒂痕类型等果实特征的变异进行了分析。结果表明,‘南月’实生后代的单果质量为0．64～2．15g,果实横径为10．0～16．4mm;果实可溶性固形物含量为9．1％-15．8％,其中有37％的单株果实可溶性固形物含量在12．0％以上;单果种子数为3～93粒,有18％的单株单果种子数小于25粒;果实颜色以蓝紫色和黑蓝紫色为主,比例分别为50％和42％;果实口感以中等和好2个等级为主,比例分别为50％和40％。在对果实的主要特征和经济性状进行评估的基础上,初步筛选出21个‘南月’实生后代优良单株。     

辣椒果实性状的遗传分析

以6个辣椒品种并按(1/2)n(n-1)双列杂交法配制的15个杂交组合为材料,根据Hayman分析法估算了辣椒果实5个性状的遗传模型和遗传参数。结果显示,果长、果肉厚和结果数的遗传符合“加性-显性”模型,果宽和单果质量不符合“加性-显性”模型,还存在显著上位性效应。遗传参数估算表明,5个果实性状遗传是以加性效应为主,但不同果实性状显性效应有较大的差异,果肉厚的显性效应最大,其次是果长和结果数,果宽和单果质量最小。     

Regulation of tomato fruit growth by epidermal cell wall enzymes

Water relations of tomato fruit and the epidermal and pericarp activities of the putative cell wall loosening and tightening enzymes Xyloglucan endotransglycosylase (XET) and peroxidase were investigated, to determine whether tomato fruit growth is principally regulated in the epidermis or pericarp. Analysis of the fruit water relations and observation of the pattern of expansion of tomato fruit slices in vitro , has shown that the pericarp exerts tissue pressure on the epidermis in tomato fruit, suggesting that the rate of growth of tomato fruit is determined by the physical properties of the epidermal cell walls. The epidermal activities of XET and peroxidase were assayed throughout fruit development. Temporal changes in these enzyme activities were found to correspond well with putative cell wall loosening and stiffening during fruit development. XET activity was found to be proportional to the relative expansion rate of the fruit until growth ceased, and a peroxidase activity weakly bound to the epidermal cell wall appeared shortly before cessation of fruit expansion. No equivalent peroxidase activity was detected in pericarp tissue of any age. It is therefore plausible that the expansion of tomato fruit is regulated by the combined action of these enzyme activities in the fruit epidermis.     

Relationship between reflectance spectra of host plant surfaces and visual detection of host fruit by Rhagoletis pomonella flies

ABSTRACT. Within host trees, male and female Rhagoletis pomonella (Walsh) flies locate visually individual fruit of apple and hawthorn, which are sites of mating and oviposition. By measuring the diffuse reflectance spectra of both fruit and foliage and by using artificially pigmented natural fruit and artificial fruit mimics, we show that fruit hue is not as important in R. pomonella fruit detection as is intensity contrast of dark fruit against a bright background of light transmitted through foliage or skylight. In discussing the fruit detection system of R. pomonella , we compare it to that of vertebrate fruit consumers and seed dispersers.     

Influence of physico-chemical traits of bitter gourd, Momordica charantia L. on larval density and resistance to melon fruit fly, Bactrocera cucurbitae (Coquillett)

Abstract:  Melon fruit fly, Bactrocera cucurbitae (Coquillett) is one of the most important pests of bitter gourd, Momordica charantia L. Because of the difficulties associated with chemical control of this pest, it is important to identify the traits associated with resistance and their influence on pest multiplication. There were significant differences in test genotypes for fruit infestation and larval density/fruit. The wild accessions, IC 256185, IC 248256, IC 213311, IC 248282, IC 256110 and IC 248281 were identified as resistance sources to melon fruit fly. There was a significant and positive correlation ( r  = 0.96) between percentage fruit infestation and larval density/fruit. Percentage fruit infestation and larval density/fruit were positively correlated with depth of ribs, flesh thickness, fruit diameter and fruit length, and negatively associated with fruit toughness. Flesh thickness and fruit diameter explained 93.0% of the total variation for fruit fly infestation, and flesh thickness and fruit length explained 76.3% of the variation for larval density/fruit. Ascorbic acid, nitrogen, phosphorus, potassium, protein, reducing sugars, non-reducing sugars and total sugars were negatively correlated, while the moisture content showed a positive association with fruit fly infestation and larval density/fruit. Moisture, potassium and reducing sugar content explained 97.4% of the total variation in fruit infestation, while moisture, phosphorus, protein, reducing and total sugars explained 85.7% variation for larval density/fruit.     

辣椒果色相关研究进展

辣椒是全球广泛种植的高经济价值茄科作物之一。在辣椒的各个经济性状中果色是最直观的重要性状之一。由于辣椒果色丰富多彩,目前已经成为研究果色遗传的一种模式植物。辣椒青熟果色与老熟果色存在差异且遗传、分子调控机制不同,本文将就辣椒这两个时期果色的遗传及分子调控机制研究做一个综述。     

Foliar application of aminoethoxyvinylglycine (AVG) delays fruit ripening and reduces pre-harvest fruit drop and ethylene production of bagged “Kogetsu” apples

Covering apple fruits with double layer waterproof bags to enhance fruit quality and evenness of blush colour is typical on many cultivars in Korea and Japan. Aminoethoxyvinylglycine (AVG) applied to unbagged apple fruits at 3–4 weeks before commercial harvest reduces ethylene production in the fruit, delays fruit ripening and reduces pre-harvest fruit drop. Spray application of AVG to trees of bagged apples should have no effect on apple ripening as there is␣no direct contact with the fruit and the translocation of AVG in apple trees is regarded as negligible. However, preliminary experiments suggested that AVG applied to trees of bagged apples reduced pre-harvest fruit drop in “Kotgetsu” apples. This study investigated the effect of spray treatments of 125 ppm of AVG on fruit drop, fruit ripening (firmness, starch conversion and soluble solids) and ethylene production to whole trees with bagged or unbagged “Kogetsu” fruit, as well as sprays of only the bagged or unbagged fruit on trees on two orchards. AVG applied to whole trees with unbagged apples reduced fruit drop from an average of 58.9% to 10.4%, delayed starch conversion and decreased ethylene production. AVG applied to whole trees with bagged fruit was equally effective in reducing pre-harvest drop, delaying fruit ripening and reducing ethylene production. Application of AVG to unbagged fruit only was nearly as effective as application to whole trees with unbagged fruit but application to bagged fruit only had no effect on fruit ripening or ethylene production. Application of AVG to bagged fruit only did reduce fruit drop to an average of 42.5% but this was not as effective as spraying unbagged fruit only or whole trees with bagged fruit. Possible mechanisms for this effect are discussed.     

Evaluation of Methods to Estimate Understory Fruit Biomass

Fleshy fruit is consumed by many wildlife species and is a critical component of forest ecosystems. Because fruit production may change quickly during forest succession, frequent monitoring of fruit biomass may be needed to better understand shifts in wildlife habitat quality. Yet, designing a fruit sampling protocol that is executable on a frequent basis may be difficult, and knowledge of accuracy within monitoring protocols is lacking. We evaluated the accuracy and efficiency of 3 methods to estimate understory fruit biomass (Fruit Count, Stem Density, and Plant Coverage). The Fruit Count method requires visual counts of fruit to estimate fruit biomass. The Stem Density method uses counts of all stems of fruit producing species to estimate fruit biomass. The Plant Coverage method uses land coverage of fruit producing species to estimate fruit biomass. Using linear regression models under a censored-normal distribution, we determined the Fruit Count and Stem Density methods could accurately estimate fruit biomass; however, when comparing AIC values between models, the Fruit Count method was the superior method for estimating fruit biomass. After determining that Fruit Count was the superior method to accurately estimate fruit biomass, we conducted additional analyses to determine the sampling intensity (i.e., percentage of area) necessary to accurately estimate fruit biomass. The Fruit Count method accurately estimated fruit biomass at a 0.8% sampling intensity. In some cases, sampling 0.8% of an area may not be feasible. In these cases, we suggest sampling understory fruit production with the Fruit Count method at the greatest feasible sampling intensity, which could be valuable to assess annual fluctuations in fruit production.