Characterization of mutations in the CPO gene in British patients demonstrates absence of genotype-phenotype correlation and identifies relationship between hereditary coproporphyria and harderoporphyria

Hereditary coproporphyria (HCP) is the least common of the autosomal dominant acute hepatic porphyrias. It results from mutations in the CPO gene that encodes the mitochondrial enzyme, coproporphyrinogen oxidase. A few patients have also been reported who are homoallellic or heteroallelic for CPO mutations and are clinically distinct from those with HCP. In such patients the presence of a specific mutation (K404E) on one or both alleles produces a neonatal hemolytic anemia that is known as "harderoporphyria"; mutations on both alleles elsewhere in the gene give rise to the "homozygous" variant of HCP. The molecular relationship between these disorders and HCP has not been defined. We describe the molecular investigation and clinical features of 17 unrelated British patients with HCP. Ten novel and four previously reported CPO mutations, together with three previously unrecognized single-nucleotide polymorphisms, were identified in 15 of the 17 patients. HCP is more heterogeneous than other acute porphyrias, with all but one mutation being restricted to a single family, with a predominance of missense mutations (10 missense, 2 nonsense, 1 frameshift, and 1 splice site). Of the four known mutations, one (R331W) has previously been reported to cause disease only in homozygotes. Heterologous expression of another mutation (R401W) demonstrated functional properties similar to those of the K404E harderoporphyria mutation. In all patients, clinical presentation was uniform, in spite of the wide range (1%-64%) of residual coproporphyrinogen oxidase activity, as determined by heterologous expression. Our findings add substantially to knowledge of the molecular epidemiology of HCP, show that single copies of CPO mutations that are known or predicted to cause "homozygous" HCP or harderoporphyria can produce typical HCP in adults, and demonstrate that the severity of the phenotype does not correlate with the degree of inactivation by mutation of coproporphyrinogen oxidase.     

Up-regulation of p21- and RhoA-activated protein kinases in human pregnant myometrium

The role of small ras homologous GTP-binding proteins in the regulation of smooth muscle contractility has become increasingly apparent but there is still little information about the presence of these proteins in human uterine smooth muscle. Messenger RNAs for p21-activated protein kinase isoforms (PAK1, PAK2, and PAK3) were detectable in both nonpregnant and pregnant human myometrial tissue. However, PAK3 protein was not detectable and the proteins for PAK1 and PAK2 were only detectable in pregnant tissue. Moreover there was a large increase in the constitutively active p34 protein fragment of PAK2 in pregnant tissue. Protein expression of RhoA-activated protein kinases isoforms (ROK1 and ROK2) also increased during pregnancy. Stimulation of RhoA signaling in pregnant myometrial tissue with lysophosphatic acid (LPA) increased the level of myosin light chain (MLC20) phosphorylation. Preincubation of the tissue with C3 toxin inhibited LPA-stimulated MLC20 phosphorylation and lowered the basal phosphorylation level of MLC20. Thus ROKS and PAKS have the potential to regulate uterine contractility and/or load-bearing during human pregnancy.     

甘肃马衔山平车前叶片δ^13C的海拔和时间差异

以甘肃马衔山自然生长的平车前为材料,比较了不同海拔高度和不同月份下叶片δ＾１３Ｃ的变化结果表明,随海拔的升高,叶片δ＾１３Ｃ值增大,生长实期叶片δ１３Ｃ也高于生长后期叶片δ＾１３Ｃ值,并且叶片δ＾１３Ｃ具有年间差异。叶片δ＾１３Ｃ的这种变化也许与植物对环境的适应有关。     

中国海南省金小蜂分类研究（膜翅目：小蜂总科：金小蜂科）

首次系统研究并报道了中国海南省分布的金小蜂,记录１５属１９种,编制了属种检索表。同时初步探讨了海南省与洲、非洲之间在金小蜂分布上的关系。     

泛蛋白连接酶Ubc9参与氧还蛋白Ref—1的降解

氧还蛋白Ｒｅｆ－１是一种双功能蛋白质,在细胞氧还调控和ＤＮＡ无嘌呤／无嘧啶损伤修复中起重要作用。发寻找与它相互作用的蛋白Ｒｉｐｓ（Ｒｅｒ－１ ｉｎｔｅｒａｃｔｉｎｇ ｐｒｏｔｅｒｎｓ）,用Ｒｅｆ－１氧还功能域进行了酵母双杂交库的筛选,得到了５种阳性克隆。其中Ｒｉｐ３经测序证实为泛蛋白连接酶Ｕｂｃ９。Ｈｅｌａ细胞中共过表达Ｕｂｃ９可以明显抑制Ｒｅｆ－１对ＡＰ－１报告系统的增强作用。Ｗｅｓｔｅｒｎ印迹     

hTERT基因片段的克隆、表达和抗hTERT抗体用于端粒酶及hTERT检测的研究

端粒酶是一种重要的肿瘤生物学标志,其活性在生殖细胞、绝大多数肿瘤细胞和体外培养的永生细胞可以测知,但在大多数体细胞中不易测出。人端粒酶由两部分组成,包括hTERC和hTERT,hTERC在正常细胞和肿瘤细胞中均有表达,而hTERT的表达似乎受到严格的调控且和端粒酶活性一致。为了检测肿瘤细胞中端粒酶及hTERT的表达,我们制备了抗hTERT蛋白的特异性多克隆抗体。首先用RT-PCR方法克隆了hTERTcDNA的一个片段,将其连接到GST融合表达载体pGEX-5X-3后在大肠杆菌中融合表达。将纯化的融合蛋白抗原免疫动物,制备抗hTERT蛋白的多克隆抗体。不同的细胞抽提物用该抗体进行了Westernblot分析,结果表明该抗体可特异识别端粒酶阳性细胞株中的hTERT及端粒酶,为端粒酶及hTERT的检测初步提供了一个简单有效的检测手段。     

类整合素在烟草花粉萌发和花粉管生长中的作用

本文研究了动物整合素VnR抗血清及动物整合素专一性抑制剂含RGD的多肽对体外及半体内培养条件下烟草花粉萌发及花粉管生长的影响。结果表明在体外培养条件下,VnR抗血清及GRGDSP肽对花粉的萌发及花粉管的生长没有明显的抑制作用,但可抑制钙调素促进的花粉萌发和花粉管的生长;两者对柱头上进行的花粉萌发及在花柱里进行的花粉管生长也有一定程度的抑制。对类整合素在花粉萌发及花粉管生长中的作用进行了讨论。     

木根麦冬与林生麦冬5S rRNA基因的进化

为了揭示多拷贝基因的进化方式, 对濒危植物木根麦冬(Ophiopogon xylorrhizus Wang et Dai) 3个居群、6个个体的294个5S rR NA 基因拷贝及其姐妹种林生麦冬(O. sylvicola Wang et Tang)的45个拷贝进行了DNA测序和序列分析,并以这个迄今发表的最大的单个物种的5S rRNA基因数据,以PAUP程序重建了分子系统发育树.结果表明: 1)所得序列呈高度多样性,长度变化在307～548碱基之间,仅13对(3.8%)相同,序列分化指数较高:木根麦冬是0.078,林生麦冬是0.032,两物种间是0.149; 2)100%的统计值支持两物种的5S rRNA 基因分别来自于祖先种的一个拷贝,即"建立者拷贝",这个拷贝在物种形成之后进行了一系列连续的扩增,形成一个直系的基因家族,而祖先种的其他拷贝在物种形成后被丢失; 3)不同拷贝是独立进化的,序列间的一致化过程很弱,这在串联重复的rR N A基因中是罕见的; 4)木根麦冬居群间曾存在频繁的基因交流,使5S rRNA 基因的许多拷贝扩散于不同居群,维持着种内较高的遗传多样性.可以认为是某些近期发生的变化,阻止了居群间的基因交流,导致该物种广泛的自交,发生自交衰退,并最后导致濒危.     

中国四斑金小蜂属分类研究及二新种记述(膜翅目：金小蜂科)

记述了中国金小蜂科金小蜂亚科的四斑金小蜂属(Cheiropachus Westwood,1828)5个种,包括2新种：马氏四斑金小蜂C. mai新种分布于甘肃(兰州);细体四斑金小蜂C. vimineus新种分布于北京。文中提供了分种检索表、新种形态描述和特征图。模式标本保存于中国科学院动物研究所动物 标本馆。