黄泥河自然保护区狍冬季栖息地选择

2009年12月—2010年1月,在黄泥河自然保护区采用样线法对狍冬季栖息地选择进行了研究。共设置了47条样线,调查了109个狍利用样方和109个对照样方,测定了海拔、坡度、坡向、坡位、隐蔽级、郁闭度、食物丰富度、灌丛盖度、树胸径、人为干扰距离、林型、裸岩、雪深、倒木和针叶树15类栖息地因子。Baileys法和Mann-WhiteyU检验表明:在黄泥河自然保护区冬季,狍喜欢在坡度平缓、平均海拔602m,位于阳坡或半阴半阳坡的中坡位上雪被较浅,食物丰富度、灌丛盖度和隐蔽级都较高的针阔混交林生境中活动,对倒木因子表现出明显的选择性,避开选择阴坡、裸岩和针叶林生境。在主成分分析中,前5个主成分中的累积贡献率达到88.6%,第一主成分贡献率为30.8%,主要反映利用样方的林型、海拔和隐蔽级的影响,第二主成分贡献率为26.5%,主要反映利用样方的食物丰富度和灌丛盖度影响。     

藏羚羊PGC-1α基因编码区的克隆与分析

以藏羚羊(Pantholops hodgsonii)及同海拔分布的藏系绵羊(Tibetan Sheep)的心肌组织为材料,提取总RNA,利用逆转录聚合酶链反应(RT-PCR)技术扩增出过氧化物酶体增生物激活受体γ辅激活因子-1α(PGC-1α)的基因编码区cDNA片段,与载体连接构建重组质粒,经转化、扩增培养、鉴定后测序。利用生物信息学方法分析显示,藏羚羊和藏系绵羊的PGC-1α基因编码区长度均为2 349 bp,编码797个氨基酸(GenBank登录号分别为:JF449959和JF449960);与其他脊椎动物PGC-1α基因的核苷酸及氨基酸序列相似性达到90%以上;其包含RNA/DNA结合位点、RNA识别基序(RRM)、与核呼吸因子1(NRF-1)及肌细胞增强因子2C(MEF2C)相互作用的区域、富含丝氨酸/精氨酸的结构域、负调节功能结构域、LXXLL模体以及TPPTTPP和DHDYCQ两个保守序列,14个氨基酸差异性位点位于以上部分功能结构域中;此外,磷酸化位点的预测提示藏羚羊可能存在一个潜在的蛋白激酶G的磷酸化位点(第329位的苏氨酸)。本研究成功克隆出了藏羚羊PGC-1α基因的编码区序列,为从能量代谢角度深入探讨藏羚羊适应高原的分子生物学机制提供了新的思路。     

Molecular Cloning and Sequence Analysis of PGC-1α cDNA in Tibetan Antelope

以藏羚羊(Pantholops hodgsonii)及同海拔分布的藏系绵羊(Tibetan Sheep)的心肌组织为材料,提取总RNA,利用逆转录聚合酶链反应(RT-PCR)技术扩增出过氧化物酶体增生物激活受体γ辅激活因子-1α(PGC-1α)的基因编码区cDNA片段,与载体连接构建重组质粒,经转化、扩增培养、鉴定后测序.利用生物信息学方法分析显示,藏羚羊和藏系绵羊的PGC-1α基因编码区长度均为2 349 bp,编码797个氨基酸(GenBank登录号分别为:JF449959和JF449960);与其他脊椎动物PGC-1α基因的核苷酸及氨基酸序列相似性达到90％以上;其包含RNA/DNA结合位点、RNA识别基序(RRM)、与核呼吸因子1( NRF-1)及肌细胞增强因子2C(MEF2C)相互作用的区域、富含丝氨酸/精氨酸的结构域、负调节功能结构域、LXXLL模体以及TPPTTPP和DHDYCQ两个保守序列,14个氨基酸差异性位点位于以上部分功能结构域中;此外,磷酸化位点的预测提示藏羚羊可能存在一个潜在的蛋白激酶G的磷酸化位点(第329位的苏氨酸).本研究成功克隆出了藏羚羊PGC-1α基因的编码区序列,为从能量代谢角度深入探讨藏羚羊适应高原的分子生物学机制提供了新的思路.     

Interactive influences of ozone and climate on streamflow of forested watersheds

The capacity of forests to mitigate global climate change can be negatively influenced by tropospheric ozone that impairs both photosynthesis and stomatal control of plant transpiration, thus affecting ecosystem productivity and watershed hydrology. We have evaluated individual and interactive effects of ozone and climate on late season streamflow for six forested watersheds (38–970 000 ha) located in the Southeastern United States. Models were based on 18–26 year data records for each watershed and involved multivariate analysis of interannual variability of late season streamflow in response to physical and chemical climate during the growing season. In all cases, some combination of ozone variables significantly improved model performance over climate‐only models. Effects of ozone and ozone × climate interactions were also consistently negative and were proportional to variations in actual ozone exposures, both spatially across the region and over time. Conservative estimates of the influence of ozone on the variability (R²) of observed flow ranged from 7% in the area of lowest ozone exposure in West Virginia to 23% in the areas of highest exposure in Tennessee. Our results are supported by a controlled field study using free‐air concentration enrichment methodology which indicated progressive ozone‐induced loss of stomatal control over tree transpiration during the summer in mixed aspen‐birch stands. Despite the frequent assumption that ozone reduces tree water loss, our findings support increasing evidence that ozone at near ambient concentrations can reduce stomatal control of leaf transpiration, and increase water use. Increases in evapotranspiration and associated streamflow reductions in response to ambient ozone exposures are expected to episodically increase the frequency and severity of drought and affect flow‐dependent aquatic biota in forested watersheds. Regional and global models of hydrologic cycles and related ecosystem functions should consider potential interactions of ozone with climate under both current and future warmer and ozone‐enriched climatic conditions.     

ICSI精子遗传和表观遗传学缺陷

卵胞浆内精子注射(Intracytoplasmic sperm injection, ICSI)技术可用于男性少精、弱精、精子畸形、无精子和常规体外受精周期失败等, 克服了精子数量不足甚至直接从附睾、睾丸获取精子来治疗不育。该技术直接将单个精子注射入卵子, 因违背自然受精的生物学法则而具有很大的遗传风险。文章对ICSI精子遗传缺陷和表观遗传缺陷及其相关疾病进行综述, 可进一步认识ICSI精子遗传与表观遗传缺陷导致后代遗传风险增加的分子的机理, 文章阐述了ICSI精子有待于通过DNA甲基化、组蛋白乙酰化等表观遗传因子进行严格质量控制, 切实降低ICSI遗传及表观遗传缺陷风险的必要性。     

紫草素及其衍生物的调控策略

紫草素及其衍生物在医药、食品、化妆品和印染等领域有着巨大的市场潜力,如何提高它们的产量已成为该领域研究的热点。综述了调控紫草素及其衍生物的合成和积累方法,主要包括高产细胞系的筛选、生产培养基的改良、外加物和外加条件的影响、基因工程调控、生物反应器的影响及分析和提取纯化技术等,并对有关紫草素及其衍生物今后的发展方向进行了展望。     

藏羚羊组蛋白去乙酰化酶1 基因编码区的克隆与序列分析

为探讨藏羚羊的低氧适应机制与高原低氧环境的相关性,采用RT-PCR 技术,首次从藏羚羊心肌组织总DNA 中克隆出组蛋白去乙酰化酶1 (Histone deacetylase1,HDAC1)基因的编码区序列。该序列全长为1 449 bp,
编码482 个氨基酸,预测其蛋白质分子量约为55 kDa。序列分析表明,藏羚羊HDAC1 基因的编码区序列与其它哺乳动物相似性超过90% ,其中与牛的相似性最高为98.27% ;它的氨基酸序列与其它哺乳动物的相似性达到
98.76% ～ 99.59%,显示出极高的保守性。利用邻接法(Neighbor-Joining,NJ 法)构建的分子系统进化树聚类结果表明,藏羚羊与牛先聚为一类,该聚类结果与传统的物种进化关系基本一致。藏羚羊HDAC1 基因编码区的成
功获得,为进一步揭示藏羚羊低氧适应的表观遗传机制奠定基础。     

Nucleotide diversity of 11S seed storage protein gene and its implications for ecological adaptation of Oryza nivara

The mechanism by which a new species arises and adapts to its environment is a fundamental question in evolutionary biology.Seed characteristics such as seed size and nutrient composition are important fitness-related traits and have been shown to vary greatly among populations and species.However,the significance of variation in seed traits in plant adaptation and speciation remains unclear.We carried out a population genetic study on nucleotide variation of one 11S seed storage protein gene(Pss) of Oryza rufipogon Griff,and O.nivara Sharma Shastry,two closely related wild rice species.By comparatively examining the genetic variation pattern of the regulatory and coding regions of Pss and fragments of six reference loci across different chromosomes,we found significantly lower polymorphisms at coding regions of the gene(PssI) in O.nivara relative to O.rufipogon.Neutrality tests indicated that the reduction of polymorphisms at PssI in O.nivara was caused by positive selection rather than population demography,implying a role of selection on the 11S seed protein gene.Further phylogenetic and principal component analyses also support the hypotheses that the origin of O.nivara was associated with the adaptive divergence on the coding region of Pss.It is most likely that higher reproductive effort would be favored when O.nivara arose from O.rufipogon populations and adapted to the environment change.     

吡虫啉对褐飞虱DNA甲基化多态性的影响

为了探知基因组甲基化是否参与了昆虫抗药性, 本研究在室内对褐飞虱 Nilaparvata lugens连续9个世代的3龄若虫施用吡虫啉, 用AFLP检测褐飞虱抗性产生过程中DNA甲基化多态性的变化。利用25对AFLP引物共获得120个位点, 其中15个位点呈现甲基化多态性, 共获得78条多态性条带。根据多态性条带在不同世代样本中出现的多少计算多态性条带比例, 其中最高比例出现在G5代（10.26%）, 最低比例出现在G6代（1.28%）。多态性条带在不同世代间比例的变化趋势表明, 褐飞虱对吡虫啉的筛选产生快速应答。在筛选早期（G1, G2和G3）世代间DNA甲基化多态性比例差异相对较小, 变化范围在3.85%～6.41%之间; 在筛选中期（G4, G5和G6）世代间比例差异较大, 变化范围在1.28%～10.26%之间; 在筛选后期（G7, G8和G9）世代间比例差异相对较小, 变化范围在5.13%～7.69%之间。结果说明, 吡虫啉的连续施用能够诱导褐飞虱基因组产生甲基化变异, 初步揭示甲基化在褐飞虱抗药性产生过程中参与了基因组的表达调控。