青海湖裸鲤mtDNA遗传多样性的初步研究

本文用BclⅠ、AvaⅠ、BamHⅠ、PstⅠ、KpnⅠ、PvuⅡ共6种限制性内切核酸酶,分析了15尾青海湖裸鲤mtDNA的限制性片段长度多态性,共检测出20个酶切位点,发现BclⅠ、BamHⅠ和PvuⅡ三种酶切类型具有多态性.根据不同个体mtDNA的酶切类型,青海湖裸鲤存在4种mtDNA单倍型,计算mtDNA多态度π值为0.0043,初步认为青海湖裸鲤在线粒体DNA上存在较丰富的群体内变异、 Abstract:An analysis of patterns of cleavage of mtDNA by restriction endonucleases was performed for 15 Gymnocypris przewalskii przewalskii.Mitochondrial DNA polymorphisms were detected in the restriction patterns generated by the following 5 enzymes,BclI,AvaI,BamH],PstI,KpnI,PvuII.Only 3 of them (BclI,BantHI,PvuII) were found to be polymorphisms.Our results shorted that there were 4 mtDNA haplotypes in Gyrnnocypris przewalskii przewalskii and the genetic divergenec(π)was 0.0043,which indicated that mtDNA genetic diversity in Gymnocypris przewalskii przewalskii is higher.     

大熊猫线粒体DNA的九种限制酶图谱

本文用9种限制性内切酶（BamHⅠ,BglⅠ,BglⅡ,EcoRⅠ,EcoRⅤ,PstⅠ,PvuⅡ,SalⅠ,XhoⅠ）分析大熊猫的线粒体DNA（mtDNA）。构建其中5种酶（BamHⅠ,EcoRⅠ,EcoRⅤ,PstⅠ,PvuⅡ）的mtDNA物理图谱。大熊猫mtDNA的分子大小约为16.4 Kb,酶切位点是随机分布。我们的结果为进一步研究大熊猫mtDNA进化提供了基础资料。     

树qumtDNA限制性内切酶图谱及其与小家鼠褐家鼠的新缘关系

本实验用ApaⅠ,AvaⅠ,BamHⅠ,BclⅠ,BglⅠ,ClaⅠ,EcoRⅠ,EcoRⅤ,HpaⅠ,PstⅠ,PvuⅡ,ScaⅠ,XbaⅠ等13种限制性内切酶分析树qu(Chiromyscus chiropus) 的mtDNA限制性片段长度多态性,并用双酶解法构建了其中8种酶的限制性内切酶图谱。根据限制性片段差异法和分子钟,计算并讨论树qu和小家鼠(Mus musculus)、褐家鼠(Rattus norvegicus)的mtDNA遗传距离和亲缘关系。结果表明树qu与褐家鼠的关系较接近,两者的分歧时间在距今1500-2000万年前,即处于中新世早中期。     

鳜及大眼鳜线粒体DNA比较研究

采用10种限制性内切酶HindⅢ、EcoRⅠ、BglⅠ、BglⅡ、BamHⅠ、PvuⅡ、PstⅠ、SalⅠ、XbaⅠ、XhoⅠ对鳜及大眼鳜肝脏线粒体DNA（mtDNA）进行了分析。鳜鱼mtDNA分子量为9.703×106u,大小为16．19kb;大眼鳜mtDNA分子量为9．603×106u,大小为16．02kb。根据单、双酶切结果构建了鳜及大眼鳜mtDNA10种酶限制性酶切图谱,并对两种鱼的mtDNA酶切图谱进行了比较。     

三大不同品种马mtDNA Cytb基因的PCR-RFLP分析

用BamHⅠ、TaqⅠ、HaeⅢ、RsaⅠ和HincⅡ5种限制性内切酶通过PCR-RFLP技术检测了包括引入品种、培育品种和地方品种的6个类型共256匹马的mtDNA Cytb基因部分序列多态性。用8%非变性聚丙烯酰胺凝胶电泳将酶切产物分离,并用银染法显色。结果BamHⅠ和TaqⅠ表现出多态,5种酶共检测到7种态型,归纳为3种单倍型,以单倍型Ⅰ和Ⅲ为主体单倍型,但通过一个特殊的酶型BamHⅠ-B分析推测所研究的马起源于一个母系祖先。     

滑鼠蛇肝线粒体DNA的限制酶图谱

用六种限制性内切酶BamHⅠ、EcoRⅠ、PstⅠ、BglⅠ、BglⅡ和SalⅠ对滑鼠蛇肝脏线粒体DNA(mtDNA)进行酶解。发现BglⅡ、PstⅠ、BamHⅠ、BglⅠ和EcoRⅠ在滑鼠蛇肝mtDNA上分别有1、2、3、3和4个切点。SalⅠ不能切割滑鼠蛇肝mtDNA。根据滑鼠蛇肝mtDNA的单酶、双酶完全酶解及部分酶解片段的数目和分子量,建立了滑鼠蛇肝mtDNA的限制酶图谱。     

鲤鱼肝组织线粒体DNA的限制性内切酶分析

用EcoRⅠI,HindⅢ,PstⅠ,BglⅡ,BamHⅠ,Xho Ⅰ, Xba Ⅰ, Sal Ⅰ和Kpn Ⅰ共9种限制性内切酶酶切对鲤鱼肝组织的mtDNA进行酶解,利用Gel-Pro Analyzer算出各酶切片段长度及mtDNA大小,测出其大小约为16．61kb(1kb=1×103b),另外,对电泳条件的优化进行了探讨,并将实骚结果与以前报道的有关酶切实验结果进行了比较,表明鲤鱼mtDNA的长度及限制性酶切位点均存在地域差异．     

限制性内切酶诱发的姊妹染色单体互换

用限制性内切酶PstⅠ,SalⅠ,PvuⅡ和BamHⅠ处理CHO细胞后,发现其SCE率升高,与对照相比,前三种酶具有显著性差异。但这些酶诱导SCE的效应与其致染色体畸变效应相比则较弱,提示引起DNA双链断裂的限制性内切酶不是SCE的强刺激物。实验结果表明,BrdU取代胸苷不能消除限制酶对底物DNA的识别及裂解。     

鸭类mtDNA限制性酶切图谱的比较研究

本文报道了番鸭、建昌鸭、杂交鸭(♀建昌鸭×(?)番鸭)和北京鸭的mtDNA限制性酶切图谱。限制性内切酶HindⅢ、PsiⅠ、BamHⅠ和EcoRⅠ在番鸭mtDNA上分别有(?)、2、2和1个酶切位点。建昌鸭、杂交鸭和北京鸭的mtDNA限制性酶切图谱完全一致。以上4种内切酶在这3种鸭子mtDNA上分别有5、4、2和1个位点。比较研究4种限制性图谱,我们得到三点结论:(1)鸭类mtDN种间差异程度很高;(2)家鸭很可能不存在mtDNA种内异质现象;(3)鸭类mtDNA为母性遗传。     

FMMU白化豚鼠线粒体DNA RFLP分析研究

目的研究FMMU白化豚鼠的mtDNA,并与花色豚鼠mtDNA进行多态性分析比较,以确定其独特的生物学特性是否与mtDNA相关。方法用碱变性法提取FMMU白化豚鼠以及花色豚鼠的mtDNA,并用AvaⅠ、BalⅠ等12种限制性内切酶进行酶切和限制性片段长度多态性分析。结果与结论FMMU白化豚鼠mtDNA和花色豚鼠mtDNA的相对分子质量相同,约为16.7×103;FMMU白化豚鼠与花色豚鼠两品系的mtDNA经AvaⅠ、BalⅠ等内切酶酶切后有3-8个酶切位点,酶切图谱完全相同,经RFLP分析FMMU白化豚鼠与花色豚鼠的mtDNA之间缺乏多态性。本实验没有发现FMMU白化豚鼠的独特的生物学特性与mtDNA相关。     

普氏原羚的食性分析

普氏原羚（Ｐｒｏｃａｐｒａｐｒｅｚｗａｌｓｋｉ）是我国特有的珍稀动物,属国家Ⅰ级保护动物,在ＩＵＣＮ１９９６年版红皮书中被列为极危级。普氏原羚曾分布于内蒙古、甘肃和青海,现仅生存于青海湖西部的鸟岛及东北部的尕海、小北湖和湖东一带,数量不足３００只。它...     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

2017年中国植物科学若干领域重要研究进展

2017年中国植物科学继续保持高速发展态势, 重大成果频出, 具体表现在中国植物学家在国际顶级学术期刊发表的文章数量平稳上升。中国植物科学领域的研究工作者成果精彩纷呈, 如新型广谱抗病机制的发现、水稻广谱抗病遗传基础及机制和疫霉菌诱发病害成灾机制研究等。2017年中国生命科学领域十大进展评选中, 有两项植物科学领域的研究成果入选。水稻生物学、进化与基因组学和激素生物学等领域学科发展突出。另外, 值得一提的是, 长期从事高等植物与代谢途径调控分子网络研究和水稻品种设计育种的李家洋院士的研究成果“水稻高产优质性状形成的分子机理及品种设计”荣获2017年国家自然科学一等奖。这一具有重大国际影响的开创性贡献标志着中国植物科学在该领域的国际科学前沿居于引领和卓越地位。该文对2017年中国本土科学家在植物科学若干领域取得的重要研究成果进行了系统梳理, 旨在全面追踪和报道当前中国植物科学领域发展的最新前沿动态, 与广大读者共同分享我国科学家所取得的辉煌成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义。综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望。     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义.综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望.     

Changes in aquatic vegetation in Rhine floodplain streams in Alsace in relation to disturbance

Abstract. Changes are described in aquatic vegetation in oligotrophic, groundwater-fed Rhine floodplain streams in Alsace (eastern France), resulting from disturbance. Disturbance factors include changes in nutrients, either permanent ones - effluent from a waste water treatment plant or trout hatcheries - or periodic ones: flooding. Regular inputs of high levels of phosphate and ammonia modified the macrophyte vegetation in these streams. The floristic composition, which was characteristic of oligotrophic waters upstream of the eutrophicated sector, changed to that of a eutrophic situation as originally found downstream. Periodic disturbance by floods which normally occur once a year, irregularly eutrophicates the small streams, causing the development of a mixture of eutrophic and oligotrophic species. Six macrophyte communities are distinguished, indicating different trophic levels. The aquatic vegetation is adapted to the variations of phosphate and ammonia levels. Hence, aquatic macrophytes can be used as bio-indicators of fluctuations in water nutrient levels in relation to the type of disturbance.