家鸡和原鸡的线粒体DNA多态性比较

本文运用１１种限制性内切酶分析了家鸡（茶花鸡、尼西鸡、大理漾濞黄鸡）和原鸡共１０只个体的线粒体ＤＮＡ限制性片段长度多态性（ＲＦＬＰ）,平均每个个检测到的片段为４０条左右。但仅发现３种变异的限制性片制性格局,即ＳｔｕＩ－Ｂ,Ｅｃａ－Ｉ－ｂ和ＲＩ－Ｂ．其中ＳｔｕＩ－Ｂ和ＳｃａＩ－Ｂ为首次报道,而且均为原鸡所物有,ＥｃｏＲＩ－Ｂ则为大理漾濞黄鸡所特有。茶花鸡和尼西鸡拥有完全相同的限制性格局。经过计算,原     

笼养白腹锦鸡觅食活动的观察

笼养条件下白腹锦鸡（Ｃｈｒｙｓｏｌｏｐｈｕｓ ａｍｈｅｒｓｔｉａｅ）的日觅食活动呈现早（７：００－８：００）和晚（１８：００－１９：００）两个明显高峰期,不同季节和天气其觅食节律有一定的差异;在一年中９月翌年４月的觅食频次较高,这可能与鸟类补充繁殖期能量消耗、积累能量御寒和保证生殖腺发育有关;逐步回归分析结果表明：影响雄鸟觅食活动的主要因素为求偶、理羽和游走;影响雄鸟觅食的主要因素是游走、理羽和静     

Multiple genotypes of mitochondrial DNA within a horse population from a small region in Yunnan province of China

mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km² in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal origins, as suggested by fossil and literature records. We think the population of horses is an amazing seed-resource pool of horses and hence deserves to be paid more attention from the view of conservation genetics. However, it is also remarkable that we did not find any typical mtDNA genetic markers which would discriminate between short horses and common domestic horses.     

Effect of pH on isoamylase production by Pseudomonas amyloderamosa WU 5315

The isoamylase activity of Pseudomonas amyloderamosa WU 5315 was stable over the pH range from 5.5 to 6.25 while only about 30% of the activity remained at pH 6.5. Low isoamylase activity (418 U ml^-1) was produced by the cells grown at high pH. Activity reached almost 3000 U ml^-1 when pH was kept below 6.0 during the fermentation. With 1% glucose plus 2% maltose instead of 3% maltose as carbon source, however, no pH control was required and the isoamylase activity of Ps. amyloderamosa WU 5315 increased to 3400 U ml^-1.     

转译优化对EPO基因在COS7细胞中表达的影响

利用ＣＯＳ７细胞暂时表达系统,研究转译起始序列对ＥＰＯ－ｃＤＮＡ表达的影响。通过ＤＮＡ重组技术,构建了原ＥＰＯ－ｃＤＮＡ表达载体ｐＣＳＶ－ＥＰＯ（１）,其转译起始序列为５＇ＡＡＴＴＣＡＴＧＧ３＇。同时通过定点突变技术,将起始序列改变成５＇ＣＣＡＣＣＡＴＧＧ３＇,而构建了另一表达载体ＰＣＳＶ－ＥＰＯ（２）。后经序列分析证明无误后和前均通过ＤＥＡＥ－ｄｅｘｔｒａｎ法转染ＣＯＳ７细胞上清,测定结果为     

杂交水稻及其“三系”线粒体DNA的AP—PCR指纹图谱

为了研究水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）细胞质雄性不育（ＣＭＳ）与线粒体基因组的关系,应用ＡＰ－ＰＣＲ 分析,用７ 个任意单引物对６ 种水稻品系线粒体ＤＮＡ 进行了扩增。水稻线粒体ＤＮＡ 的ＡＰ－ＰＣＲ 产物可分为三种类型：（１）所有供试品系均能扩增的片段,它们代表了线粒体ＤＮＡ 在进化上的保守性序列。有４ 个引物检测到这类片段。（２）２ 个以上水稻品系共同出现而在全部供试材料间存在差异的扩增片段,这类片段是检测水稻线粒体ＤＮＡ多态性的主要来源。（３）一种细胞质类型所特有的扩增片段,从引物Ｒ２ 和Ｖ５ 的扩增产物中发现了这类片段,它们可能与ＣＭＳ有关联。另外,ＷＡ型不育系珍汕９７Ａ 与其杂种之间在６ 个引物的扩增图谱上均存在不同程度的差异,说明两者的线粒体ＤＮＡ序列结构可能存在某种差别     

离体条件下诱导番茄果实状结构的再生

以番茄（Ｌｙｃｏｐｅｒｓｉｃｏｎ ｅｓｃｕｌｅｎｔｕｍ Ｍｉｌｌ．）雌蕊和幼果的组织作外植体可以诱导果实状结构的再生。这种果实状结构在离体条件下能培养成熟,成熟时具红色。解剖观察表明：果实状结构由果肉和包围在外面的果皮组成,无种子和胎座。外源激素和外植体年龄的试验揭示：１．以雌蕊组织作外植体时,仅附加外源细胞分裂素就可以诱导果实状结构的再生,外源生长素似乎不是必需的,最高的诱导频率（５０．０％ ）出现在仅附加玉米素０．５ ｍ ｇ／Ｌ的组合。２．从直径４—１２ ｍ ｍ 的幼果上分离的外植体在附加外源激素的培养基上均可诱导果实状结构的再生,但只有从直径８ ｍ ｍ 的果实分离的组织块作外植体并将它们培养在６－ＢＡＰ ２ ｍ ｇ／Ｌ,ＮＡＡ０．１ ｍ ｇ／Ｌ的培养基上时,果实状结构的诱导频率最高（６２．５％ ）。为了探讨在果实状结构再生中表现出来的细胞全能性的表达,提出了植物细胞全能性的部分表达（Ｐａｒｔｉａｌｅｘｐｒｅｓｓｉｏｎ ｏｆｐｌａｎｔ ｃｅｌｌｔｏｔｉｐｏｔｅｎｃｙ）的概念并进行了讨论。     

鹿衔草化学成分的研究：羟基肾叶鹿蹄草甙的结构鉴定

从鹿衔草（Ｐｙｒｏｌａ ｃａｌｌｉａｎｔｈａ Ｈ．Ａｎｄｒｅｓ）分离得到两个化合物。经光谱分析,确定其中１个化合物为新化合物,命名为羟基肾叶鹿蹄草甙（１, ｈｙｄｒｏｘｙｌｒｅｎｉｆｏｌｉｎ）,另一化合物为儿茶素（３）。     

刺果番荔枝中的番荔枝内酯

从刺果番荔枝（Ａｎｎｏｎａ ｍ ｕｒｉｃａｔａ Ｌ．）的种子中分离到３ 个单四氢呋喃型番荔枝内酯类化合物,用波谱方法鉴定为海南哥纳香甲素（ｈｏｗ ｉｉｃｉｎ Ａ, Ｓ１３）、乙素（ｈｏｗ ｉｉｃｉｎ Ｂ, Ｓ５）和新化合物４－去氧海南哥纳香乙素（４－ｄｅｓｏｘｙｈｏｗ ｉｉｃｉｎ Ｂ, Ｓ２）。