牛精子发生相关新基因b-DAZL的克隆、生物信息学分析与组织表达研究

人和多种动物的DAZL(Deleted in AZoosPermia-like)基因是精子发生的重要调控因子,DAZL基因突变或表达缺乏将导致精子发生过程减数分裂障碍和雄性不育.文中采用电子克隆和克隆测序方法获得了黄牛DAZL,基因cDNA全序列,利用生物信息学方法进行黄牛DAZL基因序列和蛋白结构分析,并对黄牛、牦牛和犏牛DAZL基因的组织表达特征进行了分析.结果发现黄牛DAZL,基因cDNA全长2509 bp,编码295个氨基酸(命名为b-DAZL);b-DAZL基因含有12个外显子和11个内含子,定位于牛1号染色体末端;b-DAZL基因与哺乳纲各物种同功能基因开放阅读框的同源性为90%一94%,其编码蛋白含有DAZL典型的RNA识别基序(RRM),DAZ重复基序,Pumilio一2和PABP作用位点.RT-PCR结果显示b-DAZL,基因仅在成年黄牛和成年牦牛睾丸、卵巢组织中表达,在成年F1代犏牛的卵巢组织中表达而在睾丸组织中检测不到表达信号,且犏牛睾丸组织切片表现出DAZL,基因缺失的典型精子发生障碍表型,因此推测b-DAZL基因在牛精子发生过程中发挥重要作用,可能与F1代犏牛雄性不育相关,是犏牛雄性不育的候选基因.     

牛精子发生相关新基因b-DAZL的克隆、生物信息学分析与组织表达研究

人和多种动物的DAZL(Deleted in AZoospermia-like)基因是精子发生的重要调控因子,DAZL基因突变或表达缺乏将导致精子发生过程减数分裂障碍和雄性不育.文中采用电子克隆和克隆测序方法获得了黄牛DAZL基因cDNA全序列,利用生物信息学方法进行黄牛DAZL基因序列和蛋白结构分析,并对黄牛、牦牛和犏牛DAZL基因的组织表达特征进行了分析.结果发现：黄牛DAZL基因cDNA全长2509bp,编码295个氨基酸(命名为b-DAZL);b-DAZL基因含有12个外显子和11个内含子,定位于牛1号染色体末端;b-DAZL基因与哺乳纲各物种同功能基因开放阅读框的同源性为90%—94%,其编码蛋白含有DAZL典型的RNA识别基序（RRM）,DAZ 重复基序,Pumilio-2 和PABP 作用位点.RT-PCR结果显示：b-DAZL基因仅在成年黄牛和成年牦牛睾丸、卵巢组织中表达,在成年F1代犏牛的卵巢组织中表达而在睾丸组织中检测不到表达信号,且犏牛睾丸组织切片表现出DAZL基因缺失的典型精子发生障碍表型,因此推测b-DAZL基因在牛精子发生过程中发挥重要作用,可能与F1代犏牛雄性不育相关,是犏牛雄性不育的候选基因.     

基于ChIP-seq筛选睾丸支持细胞中雄激素受体靶基因初步研究

雄激素及其受体在精子发生中有重要作用.寻找并鉴定更多雄激素及其受体的靶基因,对阐明雄激素及其受体介导精子发生的分子机制,解析其调控精子发生的网络具有非常重要的科学意义.在本研究中,我们分离了睾丸支持细胞,以睾酮刺激,并以ARKO小鼠睾丸作为背景对照,进行ChIP-seq和分析验证.数据分析显示了8679个差异表达基因,其中4830个基因在睾酮处理组表达上调,3849个表达下调.我们从差异基因中筛取了43个靶基因进行验证,其中39个基因的启动子区域找到了ARE结合位点.候选靶基因介导雄激素调控精子发生的分子机制仍有待进一步研究.本项目初步鉴定的靶基因可为进一步深入系统研究雄激素及其受体调控精子发生的机制提供参考.     

小鼠睾丸TERT表达的增龄变化

应用免疫组织化学和图像分析方法研究了10,20,30,60,90天龄的小鼠睾丸不同分化类型生殖细胞中端粒酶催化亚基TERT的表达.结果发现在精子发生过程中精原细胞及成熟精子中均未见TERT阳性表达,而初级精母细胞尤其是粗线期精母细胞和精子细胞是高表达TERT的细胞类群,附睾管上皮细胞也呈TERT阳性表达;同时TERT在小鼠个体发育过程中的表达存在着从弱到强再到弱的动态变化趋势.结果表明TERT在小鼠睾丸中的表达特点与精子发生过程密切相关,可能对维持生殖细胞遗传物质的完整性和减数分裂的正常进行发挥着重要作用.     

哺乳动物精子发生及其基因表达调控

精子发生的过程是一个受机体严密调节的过程,其中包括激素调节、睾丸旁分泌因子的调节和其它信号分子的调节,睾丸特异性表达的基因在这一调节过程中发挥着重要的作用。研究睾丸特异性表达基因的功能的最终目的是阐述精子发生的机理和发现新一代高效、特异、可逆的男性避孕药物的靶蛋白基因。     

类固醇激素受体在扬子鳄睾丸表达的免疫细胞化学研究

用免疫细胞化学方法对雄激素受体(AR)、雌激素受体(ER)和孕激素受体(PR) 在扬子鳄睾丸中进行定位研究.结果表明,三种类固醇激素受体在扬子鳄睾丸中都有分布:雄激素受体在睾丸的肌样细胞和支持细胞中呈阳性反应,雌激素受体在睾丸的间质细胞中呈 阳性反应,孕激素受体在睾丸的生精细胞中呈阳性反应.推测结果表明,雄激素受体在扬子 鳄精子发生过程有重要作用;雌激素受体可能在扬子鳄睾丸发育过程中影响睾丸间质细胞雄性激素的分泌,进而调节生精过程和精子发育成熟,孕激素受体可能通过转换成AR和ER来对精子发生进行调节.这些结果为证明性类固醇激素参与调节扬子鳄性腺生殖内分泌调控提供了重要的形态学新证据.     

睾丸支持细胞功能的研究进展*

摘要: 支持细胞位于睾丸曲细精管内皮,作为与生精细胞接触的惟一体细胞,在生精过程中起着至关重要的调控作 用。支持细胞在精子发生过程中可为精子细胞提供结构支持; 他分泌的各种蛋白质参与精子发生所需物质的转 运; 同时支持细胞表达一些膜蛋白,促进局部免疫豁免形成,为精子发生提供有利的微环境; 再者,支持细胞通过发 挥粘附与吞噬作用,清除精子发生中凋亡的精子细胞。随着研究的深入,近年来对支持细胞又有了新的认识。     

CREBBP在小鼠睾丸发育过程中表达模式的研究

睾丸是雄性动物最为重要的生殖器官,主要由曲细精管和间质构成。雄性哺乳动物持续的精子发生依赖于精原干细胞。精原干细胞通过有丝分裂自我更新,并在一些因子的诱导下启动分化进一步发育为精母细胞。研究睾丸中各细胞基因的表达调控对男性不育和睾丸生殖细胞肿瘤的治疗具有十分重要的意义。本研究利用RT-PCR、免疫组织化学及免疫荧光双染的方法主要研究了CREBBP在小鼠睾丸中的表达模式,结果显示CREBBP主要在精原细胞中表达,并在增殖状态的精原细胞中有表达,但在分化后启动了减数分裂的细胞中未检测到阳性信号。因此我们推测CREBBP可能参与了精原细胞的增殖,为后期精原细胞自我更新机制的研究提供理论基础。     

雄激素对小鼠睾丸支持细胞Akt和MEK/Erk磷酸化水平的影响

磷酸化信号通路在精子发生过程中有重要作用,本文研究小鼠睾丸支持细胞中雄激素诱导的蛋白磷酸化。研究中分离培养小鼠睾丸支持细胞,建立了稳定的培养体系。蛋白磷酸化抗体芯片结果显示,睾酮快速激活Akt及MEK/Erk的磷酸化,蛋白免疫印迹验证了芯片分析结果,且激酶磷酸化的激活是由AR介导。结果表明睾酮诱导小鼠睾丸支持细胞中Akt和MEK/Erk磷酸化。     

绒山羊曲细精管生殖细胞的长期培养和精子发生过程的观察

哺乳动物精子发生过程是生殖生物学的重要研究课题之一.为了开展对山羊精子发生过程的研究,我们首次建立了绒山羊睾丸生殖细胞原代培养方法.原代生殖细胞和支持细胞(Sertolicells)由绒山羊睾丸曲细精管组织块产生,在体外共培养超过三个月.在共培养期间,观察到绒山羊的精原干细胞分化为精母细胞和精子细胞的形态变化过程.这一方法的建立为山羊精子发生过程的研究和应用打下了基础.实验结果显示,在没有添加任何生长因子的条件下,绒山羊睾丸生殖细胞长期增生分化,不断产生精子细胞.这一结果暗示了组织块和共生的支持细胞为生殖细胞的增生和分化提供了营养因子和调节因子.生成的游离精子细胞最后全部死亡,暗示这一共培养体系不能提供变态过程所需因子.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that