Transferability of Microsatellite Markers from Brachypodium distachyon to Miscanthus sinensis,a Potential Biomass Crop

Miscanthus sinensis has high biomass yield and contributed two of the three genomes in M.x giganteus,a bioenergy crop widely studied in Europe and North America,and thus is a potential biomass crop and an important germplasm for Miscanthus breeding.Molecular markers are essential for germplasm evaluation,genetic analyses and new cultivar development in M.sinensis.In the present study,we reported transferability of simple sequence repeat (SSR) markers from Brachypodium distachyon to M.sinensis.A set of 57 SS...     

一种优化的蜜环菌分离与纯化方法

从分离材料的采集、蜜环菌索的室内培养条件、培养基的改良和分离技术的优化4个方面对前人的蜜环菌分离方法进行了系统的完善和改进。结果表明：采用蜜环菌生长良好的木本植物组织为分离材料,在15℃保湿的条件下培养可以得到健壮的菌索;按玉米粉：黄豆粉：蔗糖：水=6：1：1：26的质量比例制作的培养基不仅能满足蜜环菌生长的营养需求,而且对于其他杂菌具有明显的阻滞作用,有助于菌株纯化;分离前对菌索表面进行适当干燥可显著提高分离的成功率。     

Intragenic duplication and divergence in the spectrin superfamily of proteins

Many structural, signaling, and adhesion molecules contain tandemly repeated amino acid motifs. The alpha-actinin/spectrin/dystrophin superfamily of F-actin-crosslinking proteins contains an array of triple alpha-helical motifs (spectrin repeats). We present here the complete sequence of the novel beta-spectrin isoform beta(Heavy)- spectrin (beta H). The sequence of beta H supports the origin of alpha- and beta-spectrins from a common ancestor, and we present a novel model for the origin of the spectrins from a homodimeric actin-crosslinking precursor. The pattern of similarity between the spectrin repeat units indicates that they have evolved by a series of nested, nonuniform duplications. Furthermore, the spectrins and dystrophins clearly have common ancestry, yet the repeat unit is of a different length in each family. Together, these observations suggest a dynamic period of increase in repeat number accompanied by homogenization within each array by concerted evolution. However, today, there is greater similarity of homologous repeats between species than there is across repeats within species, suggesting that concerted evolution ceased some time before the arthropod/vertebrate split. We propose a two-phase model for the evolution of the spectrin repeat arrays in which an initial phase of concerted evolution is subsequently retarded as each new protein becomes constrained to a specific length and the repeats diverge at the DNA level. This evolutionary model has general applicability to the origins of the many other proteins that have tandemly repeated motifs.      

海南岛吊罗山蕨类植物的多样性及其保育

对海南岛吊罗山的蕨类植物进行了专题研究。吊罗山有蕨类植物 4 3科 10 0属 2 13种及 4变种 ,其中 5种为海南新记录。蕨类物种密度高达 5 5 .8种 / 10 0km2 ,为海南蕨类多样性中心之一。该地蕨类植物区系以水龙骨科和膜蕨科为优势科 ,表现出明显的热带性质 ,热带分布的科、属、种分别达到 10 0 %、93.2 %和 95 .3%。在垂直分布上 ,蕨类植物的生态特点与植被类型相关 ,随着海拔升高 ,阳生性蕨类减少 ,阴生性蕨类、附生与石生蕨类增多 ,蕨类物种多样性在海拔 6 0 0～ 10 0 0m地段最为丰富。按照 2 0 0 1年IUCN红色名录等级及标准评估 ,在海南岛范围内 ,吊罗山有 36种受威胁蕨类植物 ,其中 6种为极危物种 ,13种为濒危物种 ,17种为渐危物种 ,这 36种受威胁蕨类中有 8种属于国家II级保护植物。导致这 36种蕨类植物受威胁的原因主要有 :人为直接破坏、生境旱化和分布区限制     

Metabolic and hormonal responses during squash

The metabolic and hormonal response during squash was observed in eight normal men. Significant increases from resting were found for blood glucose, lactate, pyruvate, alanine and glycerol while total ketone bodies and plasma nonesterified fatty acids rose after play stopped. Insulin and C-peptide decreased significantly and catecholamines, ACTH, prolactin and growth hormone increased.     

Formation of N-Pyroglutamyl Peptides from N-Glu and N-Gln Precursors in Aplysia Neurons

Abstract : Matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry is used to examine the formation of N -pyroglutamate (pGlu) in single, identified neurons from Aplysia . Six pGlu peptides are identified in the R3-14 and the R15 neurons that result from in vivo processing of peptides containing either Glu or Gln at their respective N-termini. Moreover, we show that Glu-derived pGlu is not a sample collection or measurement artifact. The pGlu peptides are detected in isolated cell bodies, regenerated neurites in culture, interganglionic connective nerves, cell homogenates, and collected releasates. We also demonstrate that R3-14 cells readily convert a synthetic N -Glu peptide to its pGlu analogue, indicating the presence of novel enzymatic activity.     

热带季节雨林凋落叶分解过程中的中小型土壤节肢动物的群落结构及动态

2000年5月-2001年4月,采用尼龙网袋法,以西双版纳热带季节雨林混合凋落叶作为分解基质,在3个季节雨林样地开展分解实验,对实验过程中分解袋内的中小型土壤节肢动物(meso—microarthropod)进行取样调查。根据所获数据探讨了中小型土壤节肢动物群落在分解过程中的结构和动态。结果显示：(1)在季节雨林凋落叶分解过程中,中小型土壤节肢动物群落组成始终以弹尾目和蜱螨目相对数量较高(均在30％以上),成为优势类群。(2)分解中期,土壤节肢动物群落多样性指数,类群、个体及重要类群的数量均处于整个分解过程中的较高水平,分解初期和后期相对较低,且波动性大,其中分解初期各多样性指标在波动过程中呈逐步增长趋势,而后期逐步降低,其变化过程受凋落叶数量和质量、林地降雨量变化的影响。土壤动物群落类群和个体相对密度(每克凋落叶干重的类群数和个体数)的变化可在一定程度上反映土壤动物与凋落物质量的动态关系。(3)不同样地间,土壤节肢动物群落结构及动态差异在分解前期不明显,而分解后期差异有所增加,但3样地凋落叶分解物质损失率没有明显差异。     

濒危物种巴东木莲的等位酶遗传多样性及其保护策略

为了确定中国特有濒危植物巴东木莲(Manglietia patungensis)的就地保护优先单元和制定迁地保护的取样策略,采用超薄平板聚丙烯酰胺等电聚焦电泳技术对巴东木莲的7个野生居群的等位酶遗传多样性及遗传结构进行了分析。通过对8个酶系统19个酶位点的分析结果来看,巴东木莲具有较高的遗传多样性和一定程度的遗传分化。每位点平均等位基因数（A）为1.57,多态位点百分率（P）为48.1%,平均预期杂合度（H_e）为0.192。巴东木莲居群间的遗传分化系数（G_ST）为0.165,说明其16.5％的遗传变异存在于居群间;基于遗传分化系数计算的基因流（N_m）为1.27,说明居群间存在适度的基因流;固定指数(F)为-0.191,显示巴东木莲居群杂合体轻微过量,纯合体略显不足。本研究表明,目前巴东木莲仍具有较高的遗传多样性并且在其适宜生境中可以完成自然更新,因此应采取以就地保护为主的综合保育策略。     

高榕小蜂群落结构及物种多样性的初步研究

在西双版纳地区采集干、湿两季5个样株的高榕(Ficus altissima)隐头果,单果收蜂,鉴定蜂种,共获高榕隐头果内小蜂标本18 000多号,隶属膜翅目5科9属14种。然后对样株小蜂群落结构、组成、性比及物种多样性进行对比研究。小蜂群落的结构和组成在干、湿两季有着明显的差异：湿季隐头果内的小蜂种类比干季丰富。另外,受人为干扰较少的样株隐头果内小蜂种类比受严重干扰的样株丰富。高榕的非传粉小蜂主要由造瘿者组成,寄生小蜂和寄居性小蜂仅占很少一部分;干、湿两季的小蜂群落多样性指数均很低,虽然在湿季群落内小蜂的丰富度指数较高,但不如干季小蜂分布得均匀;相同季节的小蜂群落均为中等相似,不同季节的2个榕树小蜂群落为中等不相似,有的树对达到极不相似水平;高榕隐头果内传粉小蜂的雄雌性比(♂：♀)较低,为0.14：1,而非传粉小蜂的雄雌性比相对较高,多在1：1左右。以上研究结果表明,西双版纳地区高榕隐头果内的小蜂受不同季节温湿度、人为干扰程度等因素的影响,保护并改善西双版纳地区的生态环境对丰富高榕隐头果小蜂物种多样性有重要意义。