走进内蒙

2015年8月1日,我们每一个人收拾好行囊,整装待发,在邓涛老师带领下踏上了去往内蒙古的征程,拉开了探索灰色生命之旅的序幕. 队伍由两辆车、8人组成,我们早晨7点从中国科学院古脊椎动物与古人类研究所出发,披着清晨的阳光,摆脱城市的拥挤,缓缓地“逃离”了北京城.直到抵达张北之后我们的车子才能像矫健的马儿一样驰骋在广袤的公路上,沿途没有了城市的喧闹,没有了交通的堵塞,伴随我们的只有那一眼望去蓝蓝的天空、随风摆动的小草,以及那迷人的风景,偶尔打开车窗,一股凉爽的清风扑面而来,沁人心脾.经过一路的颠簸,我们在傍晚时刻到达锡林浩特,当地文物保护站的同志为我们安顿好了一切.     

高山栎组化石——喜马拉雅山隆升的证据

巍峨的青藏高原,雄踞于地球之巅,这片既古老而又年轻的大地,以其独特的地理景观,丰富的自然资源和悠久的地域文化,曾召唤着来自不同国度和年龄段的科学工作者致力于以“青藏高原的隆起及其对自然环境和人类活动的影响”为主题的科学研究。他(她)们在这片惊险而又充满神秘色彩的雪域高原的崎岖山路上,留下了其足迹,取得的研究成果,为青藏高原综合研究的主题增添了耐人寻味的古生物学证据。翻开亚洲新生代地质历史,喜马拉雅山的上升被认为是最重要的地质事件。由于这条东西长2400余km,南北宽200~350km的山峦重迭、群峰林立的山系隆起,不仅制约…     

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.     

昆虫孤雌生殖中中心体的组装和意义

中心体是动物细胞主要的微管组织中心(microtubule organizing center, MTOC), 负责组织纺锤体.近年来, 关于昆虫卵母细胞减数分裂后中心体形成的深入研究对阐明昆虫孤雌生殖的过程和机制以及了解孤雌生殖的进化和形成具有重要意义.综述了第一次有丝分裂纺锤体的形成、中心体的装配以及中心体对于昆虫孤雌生殖的意义, 表明昆虫孤雌生殖的普遍模式就是在没有精子提供中心粒的情况下, 卵子通过新形成的中心体进行有丝分裂, 中心体自我组装限制的解除可能是进行孤雌生殖的转折点.     

进化论系列讲座(一)自古以来的问题——我们从哪里来?

今天,当我们谈起进化论的时候,没有人不知道达尔文的鼎鼎大名.没错,正是达尔文根据自己20多年的考察、研究和思考,在1859年出版了影响世界的《物种起源》一书,创立了以自然选择为机制的生物进化理论体系.这个理论就像一盏明灯,照亮了当时那个被《圣经》的教义笼罩得黑沉沉的人类精神世界,使越来越多的人看清了有着更为客观之来龙去脉的世间万物更为真实的面目,同时也给整个科学界和人类的认识领域开启了一个全新的视野.对于生物学这支科学的舰队而言,进化论就象指南针一样,引导着代表各个分支学科的航船向着更远的方向协调前进.当这支舰队已经驶入诸如“人类基因组计划”和“克隆”技术这些现代领域的时候,回顾航迹我们发现,如果没有进化论,这个乘风破浪的远征是无法想象的.     

沉水植物光合作用测定的电化学方法

光合作用速率测定是植物光合作用研究的重要基础,沉水植物由于所处生境的特殊性,难以应用在陆生植物光合作用研究中发展起来的速率测定方法.在对水体中二氧化碳的基本特征进行详细描述的基础上,介绍了在沉水植物光合作用研究中广泛应用的电化学方法--pH-stat法和pH-drift法的原理,并给出了应用实例.这两种测定水生植物光合作用的电化学方法所依据的溶液无机碳浓度的变化可以利用Gran滴定法方便地计算出来.     

有機體舆生活條件的統一

在唯物主義的米丘林生物學的基本規律中,關於有機體與他的生活條件的統一這個命題,占據着中心地位。為了支配的目的而了解及掌握有機體的個別的發展及生物的質的改造——物種及變種的界限等,必須對這個命題作多方面的學習,才能達到。因此可見,在講授生物學原理時,使學生對於有機體與他的生活條件的統一的命題,獲得正確的了解,必須予以特別的注意。雖然初看時,這個命題,似乎是很簡單而明白的,然而這種看法往往是不正確的。     

和狗狗一起去冒险

一群雪橇犬在被冰雪覆盖的南极大陆上孤独地生活着,除了必要的觅食,还坚守着早已人去楼空的勘测站,难以想像的175天——这就是电影《南极大冒险》,一个感人至深的故事。南极大陆是令人神往的地方,圣洁的冰雪世界总给人无尽的遐想,一群科学家为了寻找火     

微生物在水环境污染物降解中的应用

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.     

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     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.