秦岭羚牛高度重复序列DNA片段的分子克隆和序列分析

羚牛(Budorcas taxicolor)属偶蹄目(Artiodactyla)、牛科(Bovidae),为我国一类大型珍贵保护动物。我们从其基因组中克隆得到若干约800bp的BamHI高度重复序列并对部分克隆进行了序列测定,发现它们显示了很高的同源性。利用其中一个单元为探针,对限制酶消化后的羚牛基因组DNA作杂交分析,发现其杂交谱带不具有个体及亚种间特异性,说明该重复序列在羚牛基因组中具有保守的分布和排列。在牛科动物中,羚牛BamHI片段与绵羊属和山羊属的相关序列具有高度同源性,而与水牛和家牛序列差异较大。这些结果为羚牛与羊亚科物种亲源关系较近的分类学观点提供了分子生物学证据。有证据表明,这些片段可能代表羚牛染色体着丝点的卫星DNA单体。     

DNA修复基因RAD24的分子克隆和序列分析

利用缺口修复（ｇａｐｒｅｐａｉｒ）方法克隆啤酒酵母（Ｓ．ｃｅｒｅｖｉｓｉａｅ）野生型ＲＡＤ２４基因,并将其亚克隆到Ｍ１３ｍｐ１８和Ｍ１３ｍｐ１９,用双脱氧末端终止法对该基因的两条链均进行了序列测定,ＤＮＡＳｔｒｉｄｅｒ程序分析显示该基因编码２６８个氨基酸的蛋白质,基因缺失试验表明,该基因为细胞生存所必需。     

高等植物DNA重复序列的主要类型和特点

高等植物核基因组的一个显著特征是其内含有大量的ＤＮＡ重复序列,因此它们在核基因组结构和功能研究中居于举足轻重的地位。一些ＤＮＡ重复序列已日趋广泛地作为分子民用于构建遗传图谱、鉴别品种、研究进化和分离目标基因等。主要介绍高等植物几类重要ＤＮＡ重复序列,如卫星ＤＮＡ、微卫星ＤＮＡ、核糖体ＲＮＡ基因、端粒重复序列和转座子等的若干特点和用途。     

鲫鱼Hind Ⅲ高重复DNA序列的分子克隆

基因组DNA高重复序列的研究有助于解释许多重要的生命现象 ,如基因调节、基因转座、基因进化等 ,还可以用于进行种群的遗传分析。鱼类的DNA高重复序列研究资料较少 ,曾在鲤科鱼类发现HindⅢ高重复序列家族。本研究用HindⅢ内切酶消化 ,从鲫鱼 (Carassiusauratusauratus)基因组DNA也克隆出一种独特的高重复序列。序列测定揭示该重复序列长度为 175bp ,在单倍体基因组的拷贝数为 1× 10 5。鲫鱼HindⅢ高重复序列与鲫鱼属 (Carassius)其它同类已知的高重复序列存在某种程度的变异 ,而与鲤科其它属的已知的HindⅢ高重复序列完全不同     

刺猬高重复顺序DNA的分子克隆及核苷酸顺序分析

为了分析比较食虫目高重复顺序的结构特征,我们将食虫目动物刺猬的高重复顺序DNA进行了分离、纯化、分子克隆,并测出了1186bp的核苷酸顺序。经分析发现在碱基组成上它与食虫目另一动物臭鼩有许多相似之处,如:G-C碱基对与A-T碱基对在整个片段中分布很不均衡;片段内部含有许多连续多次重复的短片段等,很可能为食虫目动物所特有。     

高重复序列DNA的分离与分析方法

本文介绍了一种简便快速分离动物重复序列ＤＮＡ的技术，以及与之相关的Ｃ０ｔ值的测定方法。     

TTV武汉分离株DNA克隆和序列分析

用PCR技术从一武汉病人血清中分离获得TGV DNA片断,把此DNA片断克隆到pMD18-T质粒载体中,进行全序列测定并用计算机软件对核苷酸,氨基酸序列和ORF2多肽特征进行比较和分析。所分离获得的TTV DNA片断全长1333bp,含TTV完整的ORF2及部分ORF1序列,核苷酸和氨基酸序列与其它基因型为1a的TTV分离株具有极高的同源性。ORF2多肽含202个氨基酸,在N端部分和C端部分具有较高的亲水性和较强的抗原性,而中间为一段疏水区域,抗原性较弱。N端结构以α螺旋为主,含有典型的酪氨酸激酶磷酸化价点（RARDWYPGY,38－45aa）和三个潜在的蛋白质激酶C的磷酸化位点,C端富含脯氨酸。结构以β转向为主,含有三个连续的N－十四烷酰化位点,推测ORF2编码的蛋白可能是一种磷酸化蛋白。     

小麦族植物DNA重复序列研究

近些年来从小麦族植物中分离到了许多DNA重复序列,并对其组织结构特点,物种分布特异性和在染色体上的分布特征做了广泛的研究,其中一些重复序列已被成功地用于检测遐入小麦的外源染色质和小麦族有关种属的进化研究,本文就以上诸方面进行了简要介绍。     

大麻哈鱼生长激素基因Ⅱ的分子克隆和序列分析

以λ噬菌体ＥＭＢＬ－３为基因载体,构建大麻哈鱼（Ｏｎｃｏｒｈｙｎｃｈｕｓ　ｋｅｔａ）基因组文库,并从中分离出含全长的生长激素（ｃｓＧＨ）基因的克隆。本研究首次报道了对ｃｓＧＨ全长核苷酸序列分析的结果。发现ｃｓＧＨ基因由６个外显子和５个内含子组成,长度为３３６１碱基对（ｂｐ）。由该序列可推导出含２１０个氨基酸的多肽,其中存在２２个疏水氨基酸残基的信号肽。本研究所分析的ｃｓＧＨ的外显子和内含子,其排列方式与其他鲑类（Ｓａｌｍｏｎｉｄｓ）和罗非鱼（Ｔｉｌａｐｉａ）是相似的,而与鲤科鱼类（Ｃａｒｐｓ）不同,后者外显子和内含子的排列方式与哺乳类和鸟类相似。将所测定的 ｃｓＧＨ基因的编码区与已发表的 ｃｓＧＨⅡ和ｃｓＧＨ Ⅱ两种 ｃＤＮＡ序列进行比较,证明本研究所克隆的 ｃｓＧＨ基因应属于 ｃｓＧＨ Ⅱ,因它们的编码序列 １００％同源。     

Genetic diversity of golden takin (Budorcas taxicolor bedfordi) population from Qinling Mountains in China revealed by sequence analysis of mitochondrial DNA control region

The golden takin is an endangered species, listed as a First Grade Protected animal and found only in the Qinling Mountains in China. A great deal of research on the golden takin's living habitat, population size, and home range has been conducted. Here, we employed sequence analysis of the mitochondrial DNA control region to study the genetic diversity of the golden takin from three separate nature reserve parks in the Qinling Mountains. We also compared the results of our study with previously published data on the genetic diversity of mixed takin species located in the Qinling Mountains and the Minshan area. Based on 62 sampled golden takin individuals, we found an overall mean genetic haplotype diversity of 0.687. There is no significant geographic genetic diversity across different golden takin populations within the Qinling Mountains. However, we did show significant diversity between golden takin from the Qinling Mountains and from Minshan. These original data provide a foundation for the genetic diversity of golden takin, and will yield comprehensive information for better supporting the management in the national reserve parks.     

西藏慈巴沟自然保护区羚牛栖息地选择

2001 年12 月至2002 年8 月,笔者在西藏慈巴沟自然保护区对羚牛栖息地选择性及其季节变化进行了调查研究。调查中,沿慈巴沟河谷随机选择起始点,系统地设置了187个10 m×10 m 的固定样方,记录了样方所在位置的植被类型、海拔、坡度、坡向、距水源距离、乔木密度、灌木密度、箭竹密度、郁闭度和隐蔽度等,并分别在冬、春、夏三季检查样方是否被羚牛利用。本文通过计算Vanderloeg 选择系数和Scavia 选择指数来研究羚牛对植被的选择性,结果发现羚牛冬季对杜鹃针叶林、箭竹针叶林和针阔混交林具有正选择性,春季则对箭竹针叶林和针阔混交林、夏季对高山灌丛草甸和杜鹃针叶林具有正选择性。对9 个数量化因子进行分组处理,利用Vanderloeg 选择系数和Scavia 选择指数,计算了这些因子在各个季节不同的选择性,进一步分析了羚牛对栖息地的选择性。对9 个数量化因子的判别分析表明,冬、夏及春、夏之间有极显著差异,海拔对判别函数的贡献最大,其它因子如箭竹密度、隐蔽度、郁闭度和乔木密度等贡献也较大,说明这些因子的季节分离明显。而羚牛的冬、春之间判别分析不显著,季节分离的程度较小。在结合其它分布区羚牛栖息地研究的基础上,本文探讨了食物和盐源在羚牛栖息地选择季节变化中的作用。     

羚牛秦岭亚种的产仔地特征及早期母幼关系

生育后代是每个动物在种群内扩散其遗传基因的惟一方式。确保产仔期间自身的安全和新生后代的安全,是动物种群在长期进化过程中都要面对的问题。因此,在长期进化过程中每个物种在栖息地的选择和利用方面,都将隐蔽条件作为重要的因子（Bailey,1984）。无论是在隐蔽的洞穴中产仔、还是在不利于隐蔽的草原上集群产仔,都是动物为了保证在产仔过程中免受天敌攻击和新生幼仔的安全而形成的保证种群长期存活的生存策略（Sinclair,1977;Estes and Estes,1979）。     

秦岭雄性羚牛的发情行为与其社会状态的关系

2004年5月31日至8月31日在陕西省佛坪县国家级自然保护区,对羚牛秦岭亚种（Budorcas taxicolor bedfordi）的繁殖行为及雄牛的社会状态进行了研究。研究期间每天在比较容易见到羚牛的区域内沿固定路线寻找羚牛,在不惊扰羚牛正常活动的情况下,记录牛群大小、群内个体的性别、年龄、雄性的社会状态,即是单独活动还是在繁殖群中;社会状态的变动,即每只是进入还是离开繁殖群;羚牛群中个体之间的相互关系,包括入群的独牛与群内其它雄牛之间的行为、与群内雌牛之间的行为。同时用摄像机辅助记录羚牛在群内的行为,并根据图像资料对记录的数据进行校正。研究期间累计对277 头次雄性羚牛的繁殖行为进行了观察,记录到241次繁殖行为。虽然6月初至8月下旬都可以见到羚牛的繁殖活动,但80% 以上的繁殖行为发生在6月20日至7月10日期间,其中以6月21 ～ 30日间的繁殖活动最多（105 次）。繁殖季节中雄性羚牛有两种社会状态,即在繁殖群中和单独活动（即独牛）。研究期间累计的独牛比例占成年雄性的30. 32%,其中72. 62%的独牛出现在6月10 日至7 月10 日。6 月21 ～ 30 日间独牛比例最高,占成年雄性个体的50. 67%。雄牛进出繁殖群的现象比较常见,独牛的比例与繁殖行为正相关。繁殖高峰期后,单独活动的雄牛数量迅速减少。雄牛的社会状态会随着繁殖期的不同阶段发生改变,独牛在不同繁殖群之间移动寻求更多的交配机会。我们的研究结果不支持以往认为独牛是繁殖争斗失败者的观点。     

Characterizing the behavior and reproductive biology of zoo-housed Sichuan takin (Budorcas taxicolor tibetana) using non-invasive techniques

The Sichuan takin (takin; Budorcas taxicolor tibetana) is distributed in the Gansu and Sichuan providences of southern China and along eastern Tibet. Because of their ecology, few data on takin reproductive biology exist, with the exception of its mating season in the Sichuan province, which occurs from July through August. Therefore, the objectives were to: 1) characterize reproductive hormones in zoo-housed male and female takin, including pregnancy in the female, using non-invasive fecal steroid hormonal monitoring; 2) characterize behaviors of zoo-housed takin, emphasizing reproductive behaviors and activity budget; and 3) assess the influence of season on births in North America and reproductive hormonal and behavioral activity. Fecal samples were collected 3 to 5 times per week from two adult males and three adult females. Extracted hormones were analyzed using an enzyme immunoassay for progestagen and androgen concentrations. Behavioral observations were collected for 2 yrs using an ethogram. In this study, season affected reproduction, specifically birth occurrences, reproductive cyclicity in females and androgen production in males. The duration of the estrous cycle was approximately 35 d and cycles occurred June through December. Androgen concentrations peaked in May through August. Season did not influence behavior; however, age and sex may affect some behaviors, including activity level, foraging and drinking, social affiliative behavior, and visibility from the visitor's viewpoint. In conclusion, fecal hormonal and behavioral analyses can provide information for management and conservation of this herd species.     

羚牛四川亚种在陕西秦岭分布的新记录

羚牛(Budorcastaxicolor),别名扭角羚,隶属偶蹄目牛科,有4个亚种,分别为指名亚种(B.t.taxicolor)、不丹亚种(B.t.whitei)、四川亚种(B.t.tibetana)和秦岭亚种(B.t.bedfordi),四川亚种和秦岭亚种为中国所特有(吴家炎,1986;吴家炎等,1990)。羚牛四川亚种(简称四川羚牛)分布于甘肃东南部、四川盆地西缘和西北缘的中高山地带,其分布区跨越岷山山系、邛崃山系、相岭山系、凉山山系、大雪山和沙鲁里山系(吴家炎等,1990;胡锦矗、魏辅文,1993;魏辅文、胡锦矗,1993);秦岭亚种(简称秦岭羚牛)仅分布于秦岭山脉的山地森林中(吴家炎等,1983,1990;吴家炎…     

Seasonal migration by a large forest ungulate: a study on takin (Budorcas taxicolor) in Sichuan Province, China

Migration in large mammals is a biological phenomenon that involves seasonal movements over a vertical or horizontal scale that encompasses distances of more than several home ranges. Takin are large bovid herbivores that conduct seasonal migrations. From 2006 to 2009, we utilized data from 9 GPS-collared animals and 22 trail event recorders to describe takin migration pattern at the level of both individuals and population. We found seasonal migration of takin over an elevation gradient which contained two migration cycles, with takin inhabiting the highest elevations in summer, lowest elevations in spring and autumn, and intermediate elevations during winter. These movements did not involve expansion of home range size but rather shifts in distribution. Habitat availability analysis based on five forest types indicated that takin showed significant monthly forest preferences. Based on both telemetry and trail monitors, mature forest with bamboo understory was the habitat favored by takin for more than 8 months of the year. Both methods also indicated that not all individuals migrated to the highest elevations during summer or the lowest elevations in winter. We also found that individual takin do not necessarily follow the same annual movement, as three out of the four animals with at least 2 years of data changed their migration pattern between years. Current protocols for annual surveys conducted at high-elevation meadows or low-elevation valleys are not adequate to detect all individuals. We suggest that surveys must include all potential habitats and include detection functions in order to accurately estimate takin numbers or relative changes in their density.     

Cloning and characterization of a highly repetitive fish nucleotide sequence

We have cloned and sequenced a highly repetitive HindIII fragment of DNA from the common carp Cyprinus carpio. It represents a tandemly repeated sequence with a monomeric unit of 245 bp and comprises 8% of the fish genome. Higher units of this monomer appear as a ladder in Southern blots. The monomeric unit has been sequenced; it is A + T-rich with some direct and some inverse-repeat nucleotide clusters.     

独龙江流域羚牛的种群、分布和保护

2012年11月至2013年7月间研究了独龙江乡区域羚牛指名亚种Budorcas taxicolor taxicolor(后文简称羚牛)的种群分布、数量和保护现状的问题。研究采用了改良的访问调查和实地调查相结合的方法。其中实地调查独龙江乡羚牛种群一群,调查面积35.70 km2,目测羚牛种群数量58头,适宜生境面积24.46 km2。计算羚牛适宜生境种群密度为2.4头/km2。种群数量和访查信息相符合,说明采用访问调查的方法是可靠的。本研究共计访问调查了独龙江乡的25个村庄,发现共有12个羚牛种群分布在独龙江乡,分布区羚牛适宜生境面积总和为167 km2。综合羚牛分布区面积和访查结果,本研究估算当前独龙江羚牛种群数量为400~450头。根据实地调查中羚牛利用的生境类型,利用GIS分析获得全独龙江羚牛适宜生境面积为1726 km2,可承载超过4000头,因此独龙江区域应为羚牛指名亚种的主要分布区。基于访查结果本研究还分析了羚牛的垂直分布和保护现状,提出降低人为干扰和保护羚牛生境廊道是独龙江羚牛保护的关键。