人线粒体tRNA基因突变与疾病

线粒体是体内重要的细胞器,存在于胞质内。许多生物化学反应都在线粒体内进行,其中尤为重要的是通过氧化磷酸化作用产生ＡＴＰ,供生命活动需要。线粒体内ｔＲＮＡ的总数只有２２个（核编码的ｔＲＮＡ总数至少为３０多个）。这样,线粒体ｔＲＮＡ与编码氨基酸之比基本是...     

苯、苯酚、硝基苯对水丝蚓的急性毒性及超氧化物歧化酶活性的影响

苯、苯酚、硝基苯通过工业废水排入到水域当中,是水体常见的污染物,造成水质、植被,以及水生生物一定程度的影响与危害.     

A novel <Emphasis Type="Italic">Candida glycerinogenes</Emphasis> mutant with high glycerol productivity in high phosphate concentration medium

A novel Candida glycerinogenes mutant, which possesses high glycerol productivity in a high phosphate concentration medium, was obtained by mutagenesis of an industrial glycerol producer. The mutant accumulated a total biomass of 11.5 g l⁻¹, which is less than the 15 g l⁻¹of the wild-type strain, but it consumed glucose faster than the wild-type strain did. The mutant reached its maximal glycerol concentration of 129 g l⁻¹ in 84 h compared to 96 h for the wild-type strain. High cytoplasmic glycerol-3-phosphate dehydrogenase activity of the mutant in the early glycerol formation phase, leading to a rapid glycerol synthesis and accumulation, may be the main reason for the short fermentation process.     

精原干细胞自我更新和分化的调控

精原干细胞（spermatogonial stem cells,SSCs）是体内自然状态下惟一能将遗传信息传至子代的成体干细胞,它们能通过维持自我更新和分化的稳定从而保证雄性生命过程中精子发生的持续进行。了解SSCs自我更新和分化的调节机制有助于阐明精子发生机理,并为探究其他组织中成体干细胞增殖分化的调节机制提供依据。然而目前对于SSCs自我更新和分化的调控机制所知甚少。SSCs的更新与分化遵循特定模式,受以睾丸支持细胞为主要成分的微环境及各种内分泌因素如胶质细胞源神经营养因子（GDNF）、维生素、Ets转录因子ERM/Etv5等的调控。本文评述了SSCs更新与分化的模式以及上述因素对其更新、分化的调控,探讨了其中可能涉及的信号通路,以期为本领域及其他成体干细胞相关研究提供借鉴。     

中国水螅属一新种(水螅虫纲:螅形目)

报道采自黑龙江省漠河地区北极村水螅１新种,即漠河水螅Ｈｙｄｒａ ｍｏｈｅｎｓｉｓ ｓｐ．ｎｏｖ．,模式标本保存于哈尔滨师范大学生物学系无脊椎动物教学研究室。     

Alkaline unfolding and salt-induced folding of arginine kinase from shrimp Feneropenaeus chinensis under high pH conditions

The structural and functional properties of arginine kinase (AK) in alkaline conditions in the absence or presence of salt have been investigated. The conformational changes of AK during alkaline unfolding and salt-induced folding at alkaline pH were monitored using intrinsic fluorescence emission, binding of the fluorescence probe 1-anilino-8-naphthalenesulfonate and circular dichroism. The results for the alkaline unfolded enzyme showed that much lower pH (11.0) was required to cause the complete loss of AK activity than was required to cause an obvious conformational change of the enzyme. Compared with the completely unfolded state in 5 M urea, the high pH denatured enzyme had some residual secondary and tertiary structure even at pH 13.0. Increasing the ionic strength by adding salt at pH 12.75 resulted in the formation of a relatively compact tertiary structure and a little new secondary structure with hydrophobic surface enhancement. These results indicate that the partially folded state formed under alkaline conditions may have similarities to the molten globule state which is compact, but it has a poorly defined tertiary structure and a native-like secondary structure.     

水芹水浸提液对斜生栅藻的化感效应研究

采用栅藻在不同浓度的水芹水浸提液中纯培养的方法,研究了水芹水浸提液对斜生栅藻细胞数、叶绿素含量及藻细胞超微结构的影响。结果显示,10 g·L^-1水芹水浸提液对斜生栅藻的生长和叶绿素含量的增加具有明显的促进效应;20 g·L^-1水芹水浸提液对藻细胞数和叶绿素含量的增加持续到第3 d,3 d后出现显著的抑制效应;高浓度（30~50 g·L^-1）水芹水浸提液对藻细胞数和叶绿素含量的明显抑制在第2 d始现,随时间延长而加剧,并具有浓度效应;40 g·L^-1水芹水浸提液处理后,斜生栅藻细胞壁断裂甚至消失,细胞中叶绿体片层肿胀甚至解体,核膜破裂,核质外渗。水芹水浸提液对斜生栅藻具有化感效应,低浓度促进生长,高浓度抑制。     

半乳糖凝集素1的免疫功能

半乳糖凝集素为S型凝集素,因其可特异性识别β-半乳糖苷键而得名。半乳糖凝集素1是最早发现的半乳糖凝集素家族成员,它在固有免疫与适应性免疫中均发挥着重要的作用。在固有免疫中,半乳糖凝集素1调节中性粒细胞、肥大细胞、巨噬细胞的功能,进而调节免疫反应;在适应性免疫中,半乳糖凝集素1对T细胞有重要的免疫调节功能,在T细胞存活、T细胞免疫调节、T细胞免疫疾病、炎症、肿瘤发生发展及免疫逃逸中都扮演着重要的角色。     

微生物基因组简化的研究进展

微生物基因组简化是合成生物学研究热点之一。基因组的适度精简可使细胞代谢途径得以优化,改善细胞对底物、能量的利用效率,大大提高细胞生理性能的预测性和可控性。基因组简化细胞将为生物技术的应用提供理想的底盘细胞。同顾了构建基因组简化细胞的研究策略、研究方法及一些模式生物相关研究进展,总结了基因组简化研究所面临的问题及解决办法,对基因组减小化研究发展趋势前景进行了展望。     

红茶菌抗菌蛋白产生方式的初步研究*

从红茶菌液中分离得到膜醋酸菌与裂殖酵母。采用单菌培养与混合菌培养,探讨了各菌对红茶菌抗菌蛋白的产生所起的作用。初步推断,裂殖酵母先合成相关蛋白,该蛋白经膜醋酸菌产生的酶修饰后,抗菌活力显著提高。不同属酵母与膜醋酸菌共培养,结果表明裂殖酵母优于其它酵母。