电镜分析非晶状体βγ晶状体蛋白与三叶因子蛋白复合物在人红细胞膜上的孔道形成效应

非晶状体βγ晶状体蛋白与三叶因子蛋白复合物(non-lens βγ-crystallin and trefoil factor complex,βγ-CAT)是一个从大蹼铃蟾(Bombina maxima)皮肤分泌物中分离的大然分子量为72kDa的全新的蛋白复合物.本研究测定了βγ-CAT处理红细胞后引起细胞内钾离子外流与溶血效应的时效曲线,结合扫描电子显微镜和透射电子显微镜分析βγ-CAT处理红细胞引起的早期形态学变化.结果表明:βγ-CAT(3 nmol/L)37℃处理红细胞5 min,(93.31±5.89)%的细胞内钾离子迅速外流(P＜0.01),相心溶解率为(13.12±1.92)%(P＜0.05).电子显微镜观察发现红细胞形态发生明显变化,细胞体枳增加,肿胀.少数红细胞表面向外形成棘状异常突起,部分肿胀细胞内的血红蛋白通过棘状突起缺口向细胞外喷射血红蛋白.表明βγ-CAT通过在红细胞膜上形成孔道使细胞内钾离子迅速外流导致红细胞内渗透压改变而溶血.其结果为理解βγ-CAT的溶血机制提供了直接的形态学证据.

血清白蛋白的功能及应用

血清白蛋白是脊椎动物血浆中含量最丰富的蛋白质.人血清白蛋白是由585个氨基酸组成的单链蛋白质,分子量为67 kDa.成熟的人血清白蛋白是一个心形分子,由3个结构相似的α-螺旋结构域组成.不同来源的血清白蛋白的氨基酸序列及其空间结构非常保守,它具有结合和运输内源性与外源性物质,维持血液胶体渗透压,清除自由基,抑制血小板聚集和抗凝血等生理功能.最近研究发现,蟾蜍血清白蛋白可能与其皮肤呼吸有关.人血清白蛋白目前已广泛应用于临床.

微卫星及其应用

微卫星是广泛分布于真核生物基因组中的短串联重复序列(1-5bp),具有突变速率快、多态性高等特性。已被广泛应用于生物遗传作图、群体遗传研究、个体间亲缘关系鉴定等方面。简要论述了微卫星的突变、位点的分离、数据的收集、在生物学中的应用及其存在的缺陷。

Composition and evolution of the V2r vorneronasal receptor gene repertoire in mice and rats

Pheromones are chemicals produced and detected by conspecifics to elicit social/sexual physiological and behavioral responses, and they are perceived primarily by the vomeronasal organ (VNO) in terrestrial vertebrates. Two large superfamilies of G protein-coupled receptors, V1rs and V2rs, have been identified as pheromone receptors in vomeronasal sensory neurons. Based on a computational analysis of the mouse and rat genome sequences, we report the first global draft of the V2r gene repertoire, composed of similar to 200 genes and pseudogenes. Rodent V2rs are subject to rapid gene births/deaths and accelerated amino acid substitutions, likely reflecting the species-specific nature of pheromones. Vertebrate V2rs appear to have originated twice prior to the emergence of the VNO in ancestral tetrapods, explaining seemingly inconsistent observations among different V2rs. The identification of the entire V2r repertoire opens the door to genomic-level studies of the structure, function, and evolution of this diverse group of sensory receptors. (c) 2005 Elsevier Inc. All rights reserved.

The Acquisition of an Inheritable 50-bp Deletion in the Human mtDNA Control Region Does Not Affect the mtDNA Copy Number in Peripheral Blood Cells

The mitochondrial DNA (mtDNA) control region is believed to play an important biological role in mtDNA replication. Large deletions in this region are rarely found, but when they do occur they might be expected to interfere with the replication of the molecule, thus leading to a reduction of mtDNA copy number. During a survey for mtDNA sequence variations in 5,559 individuals from the general Chinese population and 2,538 individuals with medical disorders, we identified a 50-bp deletion (m.298_347del50) in the mtDNA control region in a member of a healthy Han Chinese family belonging to haplogroup B4c1b2, as suggested by complete mtDNA genome sequencing. This deletion removes the conserved sequence block II (CSBII; region 299-315) and the replication primer location (region 317-321). However, quantification of the mtDNA copy number in this subject showed a value within a range that was observed in 20 healthy subjects without the deletion. The deletion was detected in the hair samples of the maternal relatives of the subject and exhibited variable heteroplasmy. Our current observation, together with a recent report for a benign 154-bp deletion in the mtDNA control region, suggests that the control of mtDNA replication may be more complex than we had thought. Hum Mutat 31:538-543, 2010. (C) 2010 Wiley-Liss, Inc.

In vitro construction of a recombinant human embryonic brain-derived neurotrophin-4 gene and pEGFP-N1 vector

BACKGROUND: Neurotrophin-4 (NT-4) can promote neuronal growth, development, differentiation, maturation, and survival. NT-4 can also improve recovery and regeneration of injured neurons, but cannot pass through the blood-brain barrier, which limits its ac

四种渗透性防冻剂在猕猴精子低温冷冻保存中对精子功能状态的影响

以冷冻精子的复苏运动度、荧光染料Hoechst 33258 检测的细胞膜完整率、异硫氰酸荧光素标记的 花生凝集素(FITC2PNA) 检测的顶体完整率作为精子功能状态的指标, 对甘油、二甲亚砜、乙二醇和丙二醇4 种常用渗透性防冻剂在猕猴精子冷冻保存过程中的作用进行了比较。结果表明: 冷冻保存精子的复苏运动度, 甘油(4713 ±517 %) 和乙二醇(4418 ±617 %) > 二甲亚砜(2219 ±019 %) > 丙二醇(0 ±0 %) ; 细胞膜完整 率, 甘油(5418 ±312 %) 和乙二醇(5410 ±617 %) > 二甲亚砜(3715 ±710 %) > 丙二醇(2813 ±615 %) ; 顶 体完整率, 甘油(8212 ±214 %) 和乙二醇(8214 ±214 %) > 二甲亚砜(6817 ±517 %) 和丙二醇(7213 ± 315 %) ( P < 0105) 。结果提示: 二甲亚砜和丙二醇, 尤其是丙二醇并不适合猕猴精子的冷冻保存; 而乙二醇具 有和甘油相似的保护作用, 是一种极具潜力的猕猴精子冷冻保存的渗透性防冻剂。

中国叶猴类的分类、现状与保护

国家自然科学基金

Computational fluid-structure interaction of DGB parachutes in compressible fluid flow

This paper describes large-scale simulations of compressible flows over a supersonic disk-gap-band parachute system. An adaptive mesh refinement method is used to resolve the coupled fluid-structure model. The fluid model employs large-eddy simulation to describe the turbulent wakes appearing upstream and downstream of the parachute canopy and the structural model employed a thin-shell finite element solver that allows large canopy deformations by using subdivision finite elements. The fluid-structure interaction is described by a variant of the Ghost-Fluid method. The simulation was carried out at Mach number 1.96 where strong nonlinear coupling between the system of bow shocks, turbulent wake and canopy is observed. It was found that the canopy oscillations were characterized by a breathing type motion due to the strong interaction of the turbulent wake and bow shock upstream of the flexible canopy. Copyright © 2010 by ASME.