克鲁斯假丝酵母及其近似种的脉冲电泳核型分析

用钳位均匀电场脉冲电泳(CHEF)系统分析了克鲁斯假丝酵母(Candida krusei),郎比可假丝酵母(C. lambica)和粗状假丝酵母(C. valiad)的模式菌株的电泳核型,发现这三种表型相似的假丝酵母却具有互不相同的染色体DNA分子带型,为其分类学研究提供了可靠的鉴别依据。在常规分类学研究的基础上,测定了AS 2.75(原定种名为(C. incospicua),AS2.1182(原定种名为 C. lambica)和AS 2.1772(未定种)等三株假丝酵母的G+C含量和脉冲电泳核型。通过对已报道的C. inconspicu的G+C含量及上述三种假丝酵母模式菌株的脉冲电泳核型的比较分析证明,AS 2.75和AS 2.1772为粗状假丝酵母(C. valida),AS 2.1182为克鲁斯假丝酵母(C. krusei)。     

Yeast Mutants That Produce a Novel Type of Ascus Containing Asci Instead of Spores

Tetraploid yeast cells lacking BFR1 or overexpressing an essential gene BBP1 produce a novel type of ascus that contains asci instead of spores. We show here that the asci within an ascus likely arise because a/α spores undergo a second round of meiosis. Cells depleted of Bbp1p or lacking Bfr1p are defective in a number of processes such as nuclear segregation, bud formation, cytokinesis and nuclear spindle formation. Furthermore, deletion of BFR1 or overexpression of BBP1 leads to an increase in cell ploidy, indicating that Bfr1p and Bbp1p play roles in both the mitotic cell cycle and meiosis. Bfr1p and Bbp1p interact with each other in a two hybrid assay, further suggesting that they might form a complex important for cell cycle coordination.     

朱顶红花粉萌发过程中营养细胞质的超微结构变化

本文应用透射电镜对朱顶红成熟花粉水合、活化和萌发的动态过程中营养细胞质的结构和组成变化进行了观察。成熟花粉具质体、线粒体、内质网、高尔基体。微丝束以聚集体的形式存在。花粉活化后,细胞器的数目和结构发生显著变化：质体和线粒体的片层明显增加,内质网片层狭窄,高尔基体活跃产生小泡,脂体降解及微丝聚集体散开。花粉萌发后,细胞质中出现周质微管和被刺小泡,此期细胞器的变化不明显。微丝以纤丝状遍布整个花粉管中。     

拟夏孢锈属（Uredinopsis）新记录种

采到骨状拟夏孢锈（Ｕｒｅｄｉｎｏｐｓｉｓ ｏｓｓｉｆｏｒｍｉｓ Ｋａｍｅｉ）为中国新记录种。     

无花果蛋白酶在阴离子交换树脂上的固定化

无花果蛋白酶通过８％戊二醛活化载体,共价结合到聚苯乙烯阴离子交换树脂ＧＭ２０１上,固定化作用在ｐＨ７．７,酶浓度０．８ｍｇ／ｇ树脂,４℃下进行６ｈ。得到的固定化酶表观Ｋ_ｍ值（酪蛋白,１．１１×１０~（－４）ｍｏｌ／Ｌ）小于溶液酶Ｋ_ｍ值（１．９６×１０~（－４）ｍｏｌ／Ｌ）;固定化酶活性在ｐＨ６～８保持稳定,溶液酶最适ｐＨ为７．２;固定化酶最适温度由溶液酶的５０～６０℃移至３７℃;固定化酶２５℃保持７ｄ,重复水解酪蛋白７次后,保留８３．３％活性。固定化酶对酪蛋白水解度达４７．５％,对大豆球蛋白达１１．６％。     

根霉超氧化物歧化酶同工酶类型的鉴别

利用ＫＣＮ、Ｈ_２Ｏ２和ＳＤＳ的选择性反应引起的ＳＯＤ同工酶谱带变化即可鉴别粗抽提液中的ＳＯＤ同工酶类型;用这种方法对五株不同种根霉的鉴别实验表明,它们均不同程度地含有Ｃｕ,Ｚｎ型和Ｍｎ型两种ＳＯＤ,前者约占８０％左右,后者只占２０％左右。用邻苯三酚自氧化法对样品中ＳＯＤ活性测定结果与在同工酶谱上的鉴别结果基本一致。     

Localization of nitric oxide synthase in canine ileocolonic and pyloric sphincters

The distribution of neurons containing NADPH-diaphorase (NADPH-d) activity and nitric oxide synthase-like immunoreactivity (NOS-LI) in the canine pyloric and ileocolonic sphincters was studied. Cells within the myenteric and submucosal ganglia were positive for NADPH-d. These cells generally had the morphology of Dogiel type-I enteric neurons, however, there was some diversity in the morphology of NADPH-d-positive neurons in the myenteric plexus of the pylorus. Intramuscular ganglia were observed in both sphincters, and NADPH-d was found in a sub-population of neurons within these ganglia. Dual staining with an antiserum raised against nitric oxide synthase (NOS) demonstrated that almost all cells with NOS-LI were also NADPH-d positive. Varicose fibers within ganglia and within the circular and longitudinal muscle layers also possed NOS-LI and NADPH-d activity. Dual staining with anti-VIP antibodies showed that some of the NADPH-d-positive cells in the myenteric and submucosal ganglia also contained VIP-LI, but all VIP-LI-positive cells did not express NADPH-d activity. These data are consistent with recent physiological studies suggesting that nitric oxide serves as an inhibitory neurotransmitter in the pyloric and ileocolonic sphincters. The data also suggest that VIP is expressed in a sub-population of NADPH-d-positive neurons and may therefore act as a co-transmitter in enteric inhibitory neurotransmission to these specialized muscular regions.     

含金地质体表生带中主要微生物类群的研究

通过对16个含金矿区主要微生物类群的分布、生态结构的研究,发现不同类型的金矿具有不同的微生物类群.金矿矿石与金矿酸水中的自养硫细菌和异养菌分布具有明显差异,酸性水中含自养硫细菌较多,含异养菌极少;金矿氧化带中的异氧菌一般多于自氧硫细菌,其优势菌以芽孢杆菌属中蜡状芽孢杆菌为主.研究结果揭示了金矿中存在的主要微生物类群,对阐明表生金的形成、成岩和蚀变作用具有一定的意义,对发掘生物湿法冶金菌种资源具有重要作用.     

祁连山地区植被特征及其分布规律

分析和讨论了祁连山地区主要植被类型及其分布特征。祁连山地区随着青藏高原的强烈隆升表现为整体抬升,植被具有明显的生态地理边缘效应特征和高原地带性规律。该区植被虽然受到四周的较大影响,但各类高寒植被占有绝对优势,表现出与青藏高原植被整体明显的相似性和广泛的一致性。另一方面,本区植被也有其特殊性及与高原面存在一些差异。因此,建议把祁连山地区做为青藏高原植被区的次一级独立单元