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果蝇(Drosophila melanogaster)作为最早用于研究心脏发育基因调控的模式生物,已经走过三十年的历程。果蝇心脏发育过程经历了胚胎期、幼虫期和成虫期三大阶段。在胚胎早期, Tinman、Dorsocross和Pannier等基因是关键的调控因子。Tinman参与最早的心脏前体细胞分化和心脏细胞形成,而Dorsocross和Pannier则影响心脏前体细胞的定向分化和心脏管腔的形成。进入胚胎晚期和幼虫期,果蝇的心管经历进一步的发展和重塑,该过程主要受到转录因子Hand、Mef2以及Hox基因家族的调控。在成虫期, Hox基因家族和Tinman依旧发挥重要作用。虽然果蝇心脏与脊椎动物成熟心脏存在形态上的差异,但两者心脏的早期发育过程以及调控基因和信号通路都有保守性。本文综述了果蝇心脏发育基因调控研究的三十年进展以及利用果蝇模型研究人类心脏相关疾病的潜在希望。 相似文献
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Wt1最初被认为是一种抑癌基因,现在发现其在器官形成和病理生理过程中发挥作用,它不仅影响肾脏而且影响心脏的发育。心外膜细胞在经历了上皮-间充质细胞转化后成为心血管前体细胞,之后继续分化为心肌细胞、冠状动脉血管细胞等,该过程在心脏发育中起到重要作用,而Wt1调控了这一重要的转化过程。本综述主要阐述Wt1通过Wnt/β-catenin信号通路和维甲酸信号通路调控EMT,影响心脏发育的机制。充分理解Wt1调控EMT产生心血管前体细胞的过程与分子机制,对于研究正常心脏发育及心脏再生有很大帮助。 相似文献
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真核生物通过mRNA前体的剪接,包括选择性剪接机制,调控着自身的生长与发育,了解其基本过程和有关参与因子,对进一步探索真核生物基因的表达调控和分子进化都具有极其重要的意义.该文简要综述了mRNA前体剪接的基本过程及有关剪接因子的最新研究进展,介绍了SR蛋白(Ser-Arg rich protein)家族因子、某些新发现的参与形成核不均一核糖核蛋白(heterogeneous nuclear ribonucleoprotein,hnRNP)的因子及部分:RNA解旋酶等在mRNA前体剪接过程中的功能和作用. 相似文献
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SFRP分子对心脏发育的影响 总被引:1,自引:0,他引:1
Wnt信号通路对心脏发育起着重要的作用.分泌型卷曲相关蛋白(SFRP)家族作为调控 Wnt信号的重要分子,对心脏发育和心肌分化的作用也越来越被人们所重视.最近,研究人员们对SFRP家族蛋白有了新的认识,认为它们不仅具有拮抗Wnt的作用,还对Wnt信号的转导有着复杂的调节作用.本文就SFRP分子与Wnt信号转导对心脏发育的影响进行综述. 相似文献
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高等植物雌配子体的形成涉及孢原细胞和大孢子母细胞的确立与分化、大孢子发生、功能大孢子以及胚囊的形成和发育等多种复杂调控过程。随着当代生物技术及功能基因组学的发展, 近年对雌配子体发育的研究已从细胞学描述逐渐过渡到对基因和发育调控分子机理的探索。以拟南芥、水稻和玉米等模式植物为材料进行的相关研究, 丰富了人们对于植物雌配子体和其它有性生殖过程遗传调控机理的认识。本文着重阐述了植物雌配子体发生和发育过程, 并综述了这一领域最新研究进展。 相似文献
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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 相似文献
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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. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
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. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
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. 相似文献
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The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献