A novel serine protease inhibitor from Bungarus fasciatus venom

By Sephadex G-50 gel filtration, cation-exchange CM-Sephadex C-25 chromatography and reversed phase high-performance liquid chromatography (HPLC), a novel serine protease inhibitor named bungaruskunin was purified and characterized from venom of Bungarus fasciatus. Its cDNA was also cloned from the cDNA library of B. fasciatus venomous glands. The predicted precursor is composed of 83 amino acid (aa) residues including a 24-aa signal peptide and a 59-aa mature bungaruskunin. Bungaruskunin showed maximal similarity (64%) with the predicted serine protease inhibitor blackelin deduced from the cDNA sequence of the red-bellied black snake Pseudechis porphyriacus. Bungaruskunin is a Kunitz protease inhibitor with a conserved Kunitz domain and could exert inhibitory activity against trypsin, chymotrypsin, and elastase. By screening the cDNA library, two new B chains of beta-bungarotoxin are also identified. The overall structures of bungaruskunin and beta -bungarotoxin B chains are similar; especially they have highly conserved signal peptide sequences. These findings strongly suggest that snake Kunitz/BPTI protease inhibitors and neurotoxic homologs may have originated from a common ancestor. (c) 2007 Elsevier Inc. All rights reserved.

云南哀牢山平河黑长臂猿栖息地乔木结构分析

采用样方方法对栖息于云南省哀牢山平河(E 101°17′16.1″,N 24°20′09.5″,海拔2 600 m)的黑长臂猿(Nomascus concolor)栖息地乔木层结构进行了调查.调查中共记录到乔木57种隶属于23科37属;木质藤本植物9种隶属于6科8属.优势科主要为杜鹃花科(Ericaceae)、木兰科(Magnoliaceae)、山茶科(Theaceae)和壳斗科(Fagaceae)植物.主要树种重要值排序表明,露珠杜鹃(Rhododendron irroratum)为该地区最主要的优势种,在各坡位中均有广泛分布.乔木的多样性指数、均匀度指数在沟底明显降低,而乔木1层和2层所占的比例以及木质藤本的平均多度均随着坡位的下降而升高.与其他地区的长臂猿相比,哀牢山黑长臂猿的活动程度较低(10-22 m),果实性食物种类较少.

“鱇(鱼良)白鱼人工增殖技术和种群恢复研究”取得进展

由中国科学院昆明动物研究所、玉溪市水电局、抚仙湖管理局共同承担的“鱇(鱼良)白鱼人工增殖技术和种群恢复研究”项目是中国科学院昆明分院和玉溪市政府拟定的院、市合作项目之一. 该项目于1999年4月正式启动. 为顺利开展本项目的研究, 以参加单位的有关科技人员的技术骨干, 成立了“鱇(鱼良)白鱼人工增殖技术和种群恢复研究”实验站。

饵料中类雌激素对稀有鮈鲫体内VTG的诱导

利用卵黄蛋白原(VTG)作为生物标志物评价了两种不同饵料(污水处理厂采集的水蚯蚓和丰年虫)喂养对稀有鮈鲫的雌激素效应。结果显示:饵料喂养15 d后,饲喂水蚯蚓组幼鱼体内VTG含量要显著高于饲喂丰年虫组。因此,在毒理学实验中,实验模型鱼的饵料选择对实验结果的准确保证是至关重要的。

武汉后湖长角涵螺的周年生产量

采用两种方法对后湖长角涵螺(Alocinma longicornis)的周年生产量进行了测算,结果表明,两种方法得到的生产量较为吻合.生产量的带壳湿重和去壳干重分别是:体长频率法,2.22 g/(m2·a),0.111 g/(m2·a);瞬时生长率法,2.177 g/(m2·a),0.109 g/(m2·a).对应的P/B系数为4.0,5.4.