Cofilin蛋白功能及活性调节

Cofilin是普遍存在于真核细胞的一种肌动蛋白结合蛋白. Cofilin的基本功能是在细胞内结合和解聚F肌动蛋白（F-actin）,其活性是通过磷酸化、去磷酸化、磷酸肌醇、pH改变等进行调节.cofilin介导了细胞内的信号途径,从而调节肌动蛋白骨架的重组,对肌肉形态发育起到重要作用.目前,在各种有机体中发现了许多特征性的cofilin蛋白同系物.其中鼠和人有2种cofilin蛋白：cofilin-1（non-muscle cofilin）和cofilin-2（muscle cofilin）.本文根据目前对cofilin的研究结果,从cofilin蛋白结构、功能、活性调节、在肌肉发育中的作用及相关疾病等方面进行阐述.     

Further evidence of the African antiquity of hyaenodontid (‘Creodonta’, Mammalia) evolution

We report here the new ‘creodont’ Lahimia selloumi gen. et sp. nov. from the late Palaeocene of the Ouled Abdoun Basin (Morocco) as the oldest known Hyaenodontidae with Tinerhodon from the Ouarzazate Basin (Morocco). By contrast to Tinerhodon, Lahimia is unexpectedly derived. Most of its specializations, such as the shortening of the anterior dentition (e.g. loss of P₁) and the talonid reduction and simplification, are strikingly shared with Boualitomus from the Ypresian of the Ouled Abdoun Basin, and are distinctive from other hyaenodontids, including ‘proviverrines’. They are interpreted as synapomorphies evidencing a precociously specialized early African hyaenodontid lineage. Although Lahimia and Boualitomus remain known only by the lower dentition, their relationships with Koholia are suggested by comparison of their molar occlusal pattern. Lahimia and Boualitomus are referred to the Koholiinae, which is representative of an old African endemic lineage, as initially recognized. This remarkable lineage is characterized by synapomorphies of Lahimia and Boualitomus, and also by a shared original prevallum/postvallid shearing. The discovery of Lahimia provides direct evidence for the antiquity of the African evolution of the Hyaenodontidae. This is in agreement with an African origin of the Hyaenodontidae, and with the probable diphyletism of the ‘Creodonta’. Lahimia and the Koholiinae, as well as the diversity of the first Laurasian hyaenodontid lineages, emphasize our poor knowledge of the striking early African hyaenodontid radiation.     

CRBGP通过抑制FAK-AKT通路和白介素-6的分泌抑制胶质瘤U251细胞的活性

目的 电压门控钠通道(voltage-gated sodium channels,VGSCs)表达于胶质瘤U251细胞,并影响U251细胞的增殖、侵袭和凋亡.富含半胱氨酸的颊腺蛋白(cysteine-rich buccal gland protein,CRBGP)是一种从日本七鳃鳗颊腺中分离出来的VGSCs阻断剂.本文...     

放牧后羊草和芦苇叶组织转化的比较

运用组织转化理论与分析方法,对羊草与芦苇在放牧后的叶组织转化进行了比较研究。结果表明,整个生长季内,除5月份外,芦苇的绿叶数大于羊草,羊草的绿叶长大于芦苇;2种禾草的叶片发生率和伸长率均在生长初期最大,以后逐渐降低,萎蔫率正好相反;芦苇叶片寿命短,叶组织转化快、叶组织物质积累呈抛物线型增长,如果不及时利用,会造成资源的浪费,羊草叶片寿命较长,叶组织转化慢。可以通过不同的利用方式和时间来改善羊草草地的质量。     

Genetic diversity and differentiation in natural and reintroduced populations of Bencomia exstipulata and comparisons with B. caudata (Rosaceae) in the Canary Islands: an analysis using microsatellites

Variation at five polymorphic microsatellite loci was used to investigate genetic diversity and differentiation of two tetraploid Canarian endemics, Bencomia exstipulata and B. caudata. Data were analysed and are discussed in terms of tetrasomic (autotetraploid) and disomic (allotetraploid) inheritance. In both cases, genetic diversity values were similar to those described in other tetraploid plant species. High genetic differentiation between the only two described natural populations of B. exstipulata was detected (F_ST = 0.411). Bayesian cluster analysis revealed a geographical structure with distinct genetic groups from each island. High genetic differentiation and low genetic diversity of the B. exstipulata population from Tenerife suggest a recent population bottleneck, perhaps caused by the most recent major volcanic eruption, for this natural locality. This may be heightened by possible inbreeding depression and the monoecy of these species. Polymorphic microsatellite loci were also tested across all species in the Bencomia alliance. These reliably amplified the target sequence, suggesting a high degree of conservation of the sequences flanking the microsatellites. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 429–441.     

猪CFL2b 基因cDNA克隆初步分析

利用基因表达谱芯片分析法筛选出与大白猪高肌肉产量-肌纤维形成有关的CFL2b基因.参考人和小鼠CFL2b基因序列,采用SMART-RACE技术结合EST序列拼接技术,从猪骨骼肌肌肉中首次克隆了猪CFL2b的全长cDNA序列（GenBank登录号EU561660,EU561661）,Northern杂交检测CFL2b基因 mRNA.结果表明,猪CFL2b基因含有2个转录本,长转录本3　012 bp,短转录本1　466 bp .CFL2b基因在多种真核生物中都有表达,且编码区序列非常保守,开放式读码框501 bp编码了166个氨基酸的蛋白质.氨基酸序列分析表明,猪CFL2基因与人和小鼠氨基酸同源性分别为100%和99.1%.核苷酸序列相似性分别为88.1%和74.9%.     

Anti-alpha-fodrin antibodies do not add much to the diagnosis of Sjögren's syndrome

The presence of anti-alpha-fodrin autoantibodies has been reported to be a highly specific and sensitive test for the diagnosis of Sj?gren's syndrome (SjS). We looked (in Nijmegen) for anti-alpha-fodrin, anti-Ro60, and anti-La autoantibodies in a cohort of 51 patients with rheumatic diseases (primary SjS [21], secondary SjS 6, rheumatoid arthritis [RA] 12, systemic lupus erythematosus [SLE] 6, and scleroderma 6) and in 28 healthy subjects, using ELISA, immunoblotting, and immunoprecipitation. The same samples were analyzed with an alternative anti-alpha-fodrin ELISA in Hanover. The Nijmegen ELISA of the sera from primary SjS showed sensitivities of 43% and 48% for IgA- and IgG-type anti-alpha-fodrin antibodies, respectively. The Hanover ELISA showed sensitivities of 38% and 10% for IgA- and IgG-type anti-alpha-fodrin antibodies, respectively. The ELISAs for alpha-fodrin showed six (Nijmegen) and four (Hanover) anti-alpha-fodrin-positive RA sera. IgA and IgG anti-fodrin antibodies were also present in four patients with secondary SjS. The sensitivities of Ro60 and La-antibodies in the Nijmegen ELISA were 67% and 62%, respectively. Unlike anti-alpha-fodrin antibodies, all anti-Ro60 and anti-La positive sera could be confirmed by immunoblotting or RNA immunoprecipitation. Thus, anti-Ro and anti-La autoantibodies were more sensitive than anti-alpha-fodrin autoantibodies in ELISA and were more frequently confirmed by other techniques. Anti-La antibodies appear to be more disease-specific than anti-alpha-fodrin antibodies, which are also found in RA sera. Therefore, the measurement of anti-alpha-fodrin autoantibodies does not add much to the diagnosis of Sj?gren's syndrome.     

Melon rugose mosaic virus, the cause of a disease of watermelon and sweet melon

A mechanically transmissible virus with isometric particles c. 32 nm in diameter, was isolated from infected watermelons and sweet melons in the People's Democratic Republic of Yemen. Purified virus preparations contained two major sedimenting components with sedimentation coefficients of 61S and 117S. In isopycn ic centrifugation in CsCl the particles formed a single band of buoyant density 1.39 g cm^-3. Preparations of virus particles comprised of a single polypeptide of mol. wt c. 22 000 and ssRNA of mol. wt 2.1 × 10⁶. The virus was serologically related to three of six subgroups of tymoviruses tested. The name melon rugose mosaic virus is proposed for this newly described virus.