黄土高原的一个VA菌根真菌新种：三红盾巨孢囊霉

在黄土高原中条山区发现一个盾巨孢囊霉属新种,其孢子无色透明,但球茎状连孢菌丝、芽盾及发芽菌丝均呈明显的红棕色,故命名为三红盾巨孢囊霉Scutellosporatrirubiginopa X．L. Pan & G. Y．Zhang 近似种 S. gilmorei Walker ＆ Sanders(1986)和S scutata Walker ＆ Diederichs(1989),在许多方面均不同于此新种。标本藏于山西省农科院棉花研究所。     

Biotransformation of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide,a novel potent 5‐HT7 receptor antagonist with antidepressant‐like and anxiolytic properties: In vitro and in silico approach

The aim of the study was to investigate the metabolism of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide (PZ‐1150), a novel 5‐HT₇ receptor antagonist with antidepressant‐like and anxiolytic properties, by the following three ways: in vitro with microsomes; in vitro employing Cunninghamella echinulata, and in silico using MetaSite. Biotransformation of PZ‐1150 with microsomes resulted in five metabolites, while transformation with C. echinulata afforded two metabolites. In both models, the predominant metabolite occurred due to hydroxylation of benzene ring. In silico data coincide with in vitro experiments, as three MetaSite metabolites matched compounds identified in microsomal samples. In human liver microsomes PZ‐1150 exhibited in vitro half‐life of 64 min, with microsomal intrinsic clearance of 54.1 μL/min/mg and intrinsic clearance of 48.7 mL/min/kg. Therefore, PZ‐1150 is predicted to be a high‐clearance agent. The study demonstrated the applicability of using microsomal model coupled with microbial model to elucidate the metabolic pathways of compounds and comparison with in silico metabolite predictions.     

Testing hypotheses driving genetic structure in the cooperatively breeding Brown‐headed Nuthatch Sitta pusilla

Habitat fragmentation has often been implicated in the decline of many species. For habitat specialists and/or sedentary species, loss of habitat can result in population isolation and lead to negative genetic effects. However, factors other than fragmentation can often be important and also need to be considered when assessing the genetic structure of a species. We genotyped individuals from 13 populations of the cooperatively breeding Brown‐headed Nuthatch Sitta pusilla in Florida to test three alternative hypotheses regarding the effects that habitat fragmentation might have on genetic structure. A map of potential habitat developed from recent satellite imagery suggested that Brown‐headed Nuthatch populations in southern Florida occupied smaller and more isolated habitat patches (i.e. were more fragmented) than populations in northern Florida. We also genotyped individuals from a small, isolated Brown‐headed Nuthatch population on Grand Bahama Island. We found that populations associated with more fragmented habitat in southern Florida had lower allelic richness than populations in northern Florida (P = 0.02), although there were no differences in heterozygosity. Although pairwise estimates of F_ST were low overall, values among southern populations were generally higher than northern populations. Population assignment tests identified K = 3 clusters corresponding to a northern cluster, a southern cluster and a unique population in southeast Florida; using sampling localities as prior information revealed K = 7 clusters, with greater structure only among southern Florida populations. The Bahamas population showed moderate to high differentiation compared with Florida populations. Overall, our results suggest that fragmentation could affect gene flow in Brown‐headed Nuthatch populations and is likely to become more pronounced over time.     

中华绒螯蟹白化症、正常肝胰腺组织结构及脂肪酸组成的比较研究

采用气相色谱、组织学及电镜技术分别对中华绒螯蟹雄蟹白化症肝胰腺与正常肝胰腺脂类和脂肪酸组成、显微及超微结构进行了比较研究,结果表明：正常肝胰腺的总脂含量（31.54%肝胰腺湿重）显著高于白化症肝胰腺（19.07%肝胰腺湿重）,两种蟹肝胰腺的脂类组成没有显著差异,但脂肪酸组成存在一定的差异,白化症肝胰腺中C18∶1的含量显著高于正常肝胰腺,中性脂和极性脂HUFA正常蟹肝胰腺含量都高于白化症蟹,但没有显著差异。组织学结果和超微结构观察表明：白化症肝胰腺肝小管的上皮细胞壁结构紊乱,微绒毛及微绒毛黏膜大部分脱落,细胞内仅见有零星的线粒体、脂肪滴分布,R细胞呈现空泡化。     

竹叶眼子菜居群遗传多样性和克隆结构

采用ISSR技术对长江中游南岸豹澥湖和大冶湖不同生境中的竹叶眼子菜(Potamogeton malaianus)居群的遗传多样性及克隆结构进行了研究.结果表明,在两居群的106株个体中,利用6条ISSR引物共得到40条符合3/N标准并无连锁不平衡的清晰位点,竹叶眼子菜具有较高的遗传多样性,其多态位点百分率为75.0％,Shannon多样性指数为0.3736, 两居群的遗传分化很小.竹叶眼子菜的克隆多样性很高(D=0.9917),两居群间的克隆分化很大,不具有共有的基因型.竹叶眼子菜的基株分布为游击型构型,位于湖心的大冶居群克隆距离(3.0～31.5 m)明显地大于湖岸豹澥居群(2.4～6.7 m).     

玉米赤霉烯酮生物合成和降解的研究进展

介绍了玉米赤霉烯酮及其6个衍生物的分子结构,以及玉米赤霉烯酮的生物合成途径。阐述了玉米赤霉烯酮生物合成的基因序列群以及基因簇的表达方式。论述了玉米赤霉烯酮钝化和降解过程, 探讨了玉米赤霉烯酮水解酶在基因工程中的应用研究, 并为今后玉米赤霉烯酮生物工程降解研究提出了建议。     

中国蚌螨属支序分类分析(蜱螨亚纲:蚌螨科)

选择35个特征对我国蚌螨属15种的支序分析结果表明:蚌螨P-Ⅳ(胫节)端腹部的指状突是将它们聚集成两群的主要特征.今村蚌螨P-Ⅳ端腹部仅具有短矩,与外群最近,认为是我国的蚌螨属水螨中最原始的种类;雌螨前殖吸盘板的形态影响戊蚌螨亚属与多盘蚌螨亚属的种类聚类,由此推测可以将蚌螨P-Ⅳ端腹部的指状突与雌螨前殖吸盘板的形态也作为蚌螨亚属的区分特征.由于殖吸盘结构简单是祖征态之一,因此认为具有5对殖吸盘的邻近蚌螨比6对殖吸盘的厚蚌螨更原始.雌螨具有1对殖吸盘板的寄蚌螨亚属种类与沃蚌螨亚属种类在支序系统树中形成姊妹群,结果支持Vidrine 将沃蚌螨亚属从寄蚌螨亚属中分离的修订.