眼镜蛇科 cathelicidin 基因的分子克隆及活性研究

Cathelicidins 是天然免疫系统中的一种带正电的宿主防御肽段，它们广泛地 分布在哺乳类及其他一些物种如鱼类，鸟类中。它们均包含保守的前肽区和多变 的C-末端成熟抗菌肽区域，该抗菌肽区域无论是在种间还是种内都不保守。 我们首次分别从爬行纲眼镜蛇科的眼镜蛇，金环蛇，眼镜王蛇三种毒蛇的毒 腺cDNA 文库中克隆了3 个cathelicidin 编码序列。所克隆到的序列编码的开放 阅读框架均长576bp，编码191 个氨基酸残基组成的蛋白前体。从cDNA 开放阅 读框推导得到的毒蛇cathelicidin 都含有22 个氨基酸残基组成的信号肽， 135 个 氨基酸残基组成的cathelin 保守区域以及34 个氨基酸残基组成的成熟肽区域。 与哺乳类中的cathelicidin 基因的高度多样性不同，来源于3 种毒蛇的cathelicidin 基因在核酸和蛋白水平都比较保守。结构分析表明，以上3 种毒蛇的cathelicidin 成熟肽由第157 位的Val 被elastase 切割而产生。采用化学合成法合成推导得到 的眼镜王蛇的cathelicidin（OH-CATH）。在1% NaCl 的浓度下，该合成肽对测试 的多种细菌具有很强的抑菌活性，MIC 值为1-20 μg/ml。与此同时，即使当浓度 高达200 μg/ml 时，该合成的肽段对人的红细胞依然没有溶血活性。对脊椎动物 的cathelicidin 遗传进化树分析发现毒蛇类的cathelicidin 聚在一起。从进化上看， 蛇的cathelicidin 与来源于小鼠、大鼠、兔的中性粒细胞颗粒蛋白更接近。毒蛇 的cathelicidin 可能为新药开发提供了一个很好的模板。

Methylation and gene mutation in eukaryotic DNA

5-methylcytosine (m(5)C) as a rare base exists in eukaryotic genomes, which is a normal constitution in many eukaryotic DNA and the existence of m(5)C is a feature of eukaryotic DNA. Under regular physiological conditions, cytosine of eukaryotic DNA is usually methylated. Up to the present, many people consider that the m(5)C may be mutation hotspots by the deamination leading to gene mutation. Our study indicated that the spontaneous mutation caused by the transition of G.C --> A.T, in eukaryotic DNA, may result from the tautomer changing of base pairs and may also be cause by other factor actions, however it could not be caused by the deamination of m(5)C.

Pharmacokinetics of sifuvirtide, a novel anti-HIV-1 peptide, in monkeys and its inhibitory concentration in vitro

Aim: To study the pharmacokinetics of sifuvirtide, a novel anti-human immunodeficiency virus (HIV) peptide, in monkeys and to compare the inhibitory concentrations of sifuvirtide and enfuvirtide on HIV-1-infected-cell fusion. Methods: Monkeys received 1.2 mg/kg iv or sc of sifuvirtide. An on-line solid-phase extraction procedure combined with liquid chromatography tandem mass spectrometry (SPELC/MS/MS) was established and applied to determine the concentration of sifuvirtide in monkey plasma. A four-I-127 iodinated peptide was used as an internal standard. Fifty percent inhibitory concentration (IC50) of sifuvirtide on cell fusion was determined by co-cultivation assay. Results: The assay was validated with good precision and accuracy. The calibration curve for sifuvirtide in plasma was linear over a range of 4.88-5000 mu g/L, with correlation coefficients above 0.9923. After iv or sc administration, the observed peak concentrations of sifuvirtide were 10626 +/- 2886 mu g/L and 528 +/- 191 mu g/L, and the terminal elimination half-lives (T,12) were 6.3 +/- 0.9 h and 5.5 +/- 1.0 h, respectively. After sc, T-max was 0.25-2 h, and the absolute bioavailability was 49% +/- 13%. Sifuvirtide inhibited the syncytium formation between HIV-1 chronically infected cells and uninfected cells with an IC50 of 0.33 mu g/L. Conclusion: An on-line SPE-LC/MS/MS approach was established for peptide pharmacokinetic studies. Sifuvirtide was rapidly absorbed subcutaneously into the blood circulation. The T-1/2 of sifuvirtide was remarkably longer than that of its analog, enfuvirtide, reported in healthy monkeys and it conferred a long-term plasma concentration level which was higher than its IC50 in vitro.

懒猴能量需求的研究

三组成年懒猴(Nycticebus coucang bengalensis)日均摄入量能值分别为210.19kJ/kG, 177.222kJ/kG和161.608kJ/kG; 日均消化能分别为191.89kJ/kG, 155.131kJ/kG 和146.783kJ/kG。据统计学方差及t测验分析表明:I—Ⅱ组之间和I—Ⅲ之间的日 均摄食量能值及日均消化能均有显著性差异。实验结果表 明: I组所饲喂的配 合饲料的组成优于Ⅱ、Ⅲ组并可做为懒猴 的长期用配方。表4参8

黑长臂猿（Hy lobates concolor）对人类和非人类捕食者的回避行为

捕食和避免捕食在动物生存和进化过程中起着重要作用．本文报道了我们自１９９０年３月至．１９９２年元月观察黑长臂猿（Ｈｙｌｏｂａｔｅｓｃｏｎｃｏｌｏｒ）对人类和非人类捕食者的一系列反映．在遇到人类（观察者）后，据离观察者的远近和受惊程度不同，它们表现出５种回避方式．而在遇到非人类捕食者时，成年雌雄性一起将捕食者引开，以保护其后代个体免遭捕食．文中还对这些不同的行为方式进行了讨论．成年雄性是群体的主要保护者，成年雌性在群体保护中也起到重要的作用，不同个体的邀免捕食行为又有所不同，特别是幼体．

中国猕猴类(Macaca)的演化

对6种中国分布猕猴某些头骨特征的比较和35个比例性状的聚类分析, 并对 这几个种的亲缘关系进行了探讨。结果表明: M. assamensis和M. thibetana.M. mulatta和M. cyclopis关 系最为接近, 在前两者相聚以后, 与M. nemestrina相 聚成一大支系, 后两者与M. arctoides相聚成另一大支系, 最后两大支系聚在 一起成为中国猕猴类的亲缘关系。图1表1参21

A new species of the genus Tor from Yunnan, China (Teleostei : Cyprinidae)

A new species of the subfamily Barbinae, Tor yingjiangensis, is recognized from Yunnan province, China. It can be distinguished from other Tor species by the following combination of characters: last simple dorsal-fin ray osseous and non-serrated; no forward directed predorsal procumbent spine; head length considerably longer than body depth; no tubercles on the snout or sides of the face; 18-20 gill rakers on the outside of first gill arch; 24-26 lateral line scales; median lobe of lower lip short, its posterior margin truncate, not extending to the vertical across the inner corners of the mouth; and the condition of the lower lip consistent in individuals of different sizes. The new species has been misidentified previously as Tor putitora (Hamilton, F. 1822. An account of the fishes found in the River Ganges and its Branches. Edinburgh & London. 405 pp), which occurs in the Ganges and Indus River basins. The new species can easily be distinguished from T. putitora by having 3-3.5 (vs. 2.5) scales from lateral line to pelvic-fin origin, shorter caudal peduncle length (13.0% vs. 17.2% of standard length), lesser body depth (26.4% vs. 24.0% of standard length) and longer caudal peduncle depth (12.0% vs. 10.9% of standard length), no longitudinal stripe present along side of body, and eyes visible in ventral view of head.

Exaggerated Status of

Given its relative ease, screening the entire mitochondrial DNA (mtDNA) for heteroplasmic or novel homoplasmic mutations has become part of the routine diagnostic workup for the molecular geneticist confronted with a disease case exhibiting clinical and b

独龙牛遗传多样性及其种群遗传结构的等位酶分析

用水平切片淀粉凝胶电泳技术, 进行30头独龙牛41种蛋白质共计44个遗传座位的等位酶分析,只在Tf、Hp、Amy、Est等4个座位发现多态性。每个座位等位基因的平均数、多态座位百分 比和平均杂合度值分别为A=1.0909、P=0.0682和H=0.0262。贡山县和福贡县独龙牛群体从酶基因的角度上看遗传多样性贫乏, 可能是分别由小种群引种而来, 受到瓶颈效应的作用, 并伴随着创立者事件的发生。表3参12