9 resultados para OVIS

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Dalai-lamae (Ovis ammon dalai-lamae), Gobi (O. a. darwini), Kara Tau (O. a. nigrimontana) and Tibetan (O. a. hodgsoni) argali share a 2n = 56 diploid chromosome number and a karyotype consisting of 2 pairs of biarmed and 25 pairs of acrocentric autosomes, a large acrocentric X and a minute Y chromosome. The Giemsa-banding patterns of the largest pair of biarmed chromosomes were identical to those of the largest biarmed chromosomes in all wild sheep and domestic sheep of the genus Ovis. The banding patterns of the second pair of biarmed chromosomes (metacentric) were identical to the third pair of biarmed chromosomes in Ovis with 2n = 54 and to the third largest pair of chromosomes in the 2n = 52 karyotype of Siberian snow sheep (O. nivicola). The G-banded karyotypes of dalai-lamae, darwini, hodgsoni and nigrimontana are consistent with all subspecies of argali (O. ammon), except that the Y chromosome is acrocentric instead of metacentric as typical of the argaliform wild sheep and Ovis. The Dalai-lamae and Tibetan argali specimens exhibit the light-colored, long-haired ruffs and body coloration typical of argalis from the Tibetan Plateau. The Gobi argali, from the extreme western Gobi, is similar to the dark phase argali.

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Based on mitochondrial cytochrome b gene sequence analysis, the history of true sheep ( Ovis) began approximately 3.12 million years ago ( MYA). The evolution of Ovis resulted in three generally accepted genetic groups: Argaliforms, Moufloniforms, and Pac

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The phylogenetic relationship of several subspecies of Ovis ammon were analyzed by comparing DNA sequences within the entire mitochondrial D-loop region. Five putative subspecies of ammon (dalai-lamae, darwini, hodgsoni, sairensis and adamerzi) were sampled from four provinces in China [Xinjiang, Qinghai, Gansu and Xizang (Tibet)] and two (servertzovi and nigrimontana) from Uzbekistan. The argalis sampled represent most of the currently recognized putative Subspecies of argali. Analysis of mtDNA sequences revealed high variability within ammon (7.7%), ranging from 2.4 to 11.5%. MaxiMUM-Parsimony tree indicated that nigrimontana from Uzbekistan diverged First, followed by severtzovi from Uzbekistan. The dispersal of argalis into China gave rise to three clades, suggesting that the argali originated in Western Asia and then dispersed throughout the central Asian highlands on a southeastward course. Among the Chinese argalis, mtDNA analysis places dalailamae genetically closer to hodgsoni than to darwini. Severtzovi and.. nigrimontana are two separate subspecies and genetically distinct from the Chinese argali.

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Chromosomal homologies have been established between the Chinese muntjac (Muntiacus reevesi, MRE, 2n = 46) and five ovine species: wild goat (Capra aegagrus, CAE, 2n = 60), argall (Ovis ammon, OAM, 2n = 56), snow sheep (Ovis nivicola, ONI, 2n = 52), red goral (Naemorhedus cranbrooki, NCR, 2n = 56) and Sumatra serow (Capricornis sumatraensis, CSU, 2n = 48) by chromosome painting with a set of chromosome-specific probes of the Chinese muntjac. In total, twenty-two Chinese muntjac autosomal painting probes detected thirty-five homologous segments in the genome of each species. The chromosome X probe hybridized to the whole X chromosomes of all ovine species while the chromosome Y probe gave no signal. Our results demonstrate that almost all homologous segments defined by comparative painting show a high degree of conservation in G-banding patterns and that each speciation event is accompanied by specific chromosomal rearrangements. The combined analysis of our results and previous cytogenetic and molecular systematic results enables us to map the chromosomal rearrangements onto a phylogenetic tree, thus providing new insights into the karyotypic evolution of these species.

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盘羊(Ovis amman)又称大角羊、大头羊,为山地岩栖动物,隶属偶蹄目牛科绵羊属,国家二类保护动物。盘羊具有角大而粗的外形特征,雌雄皆有,但雌性角较小,体型粗壮有力,为亚洲中部高山代表动物,在我国主要分布于新疆、西藏、青海、内蒙、甘肃等地,有关盘羊的地理分布、食性、活动规律等的研究已有报道,但盘羊的细胞遗传学研究在国内尚属首次。

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兔属物种的形态特征差异甚微,其分类地位长期存在争议。本研究论文来用线粒体DNA标记从分子水平对兔属物种的系统发育,分类地位以及历史生物地理学进行探讨。我们应用四个线粒体DNA标记:细胞色素b和125基因全序列,ND4和控制区部分序列构建中国野兔和世界范围内的其它兔属物种间的系统发育关系。系统发育关系的构建以鼠兔为外群,采用三种方法:最大简约法(淤),最大似然法(ML)和贝叶斯方法(Bl)。分析结果显示:中国野兔并不是一个单系群。世界范围内的兔属动物形成一个单系,并以地理分布可分为相应的三个种组:北美种组(NortoAmericanspeciesgroup),欧亚种组①urasionspeciesgroP)和非洲种组(S。uthAfricanspeciesgroup)。兔属动物鉴定的29个种可能多于该属的有效种。历史生物地理学的祖先地分析表明:兔属动物起源于北美大陆,通过白令大陆桥扩散到欧亚大陆,最后到达非洲大陆。Brooks简约分析(BPA)揭示兔属物种形成是在扩散事件之后,在不同的地理区域适应当时的生态环境导致种的发生。兔属动物经历了一个快速扩散和种发生的过程。贝叶斯放松分子钟方法估计种组内的分化时间显示:兔属物种的形成是在上新世早期(Plioceneepoch:4.29-5.39MyA)。云南兔(L.comusGAllen1927)是仅分布于云贵高原上的唯一一种兔属物种。我们应用线粒体DNA控制区第一高变区检测云南兔的群体遗传结构和系统地理结构模式,评价地理隔离,如高山、河流等对该物种的群体结构和系统地理模式的影响。分子变异分析显示(AMOVA)不同的地理区域间遗传差异明显,而且成对遗传差异与相应的地理距离成线性关系。错配核普酸分析(Mismatchanalysis)表明云南兔群体近期没有群体扩张。系统地理学的嵌套分析法揭示云南兔现有的群体遗传结构和遗传分化与云南高原复杂的地形地貌相关。高山、河流等地理隔离导致群体间有限的基因流形成了现有云南兔群体的分布。云南兔不同地理区域单倍型的分子系统分析以及明显的群体分化建议云南兔两个亚种的划分(L.c.comusandL.c.peni)。雪兔种组(thetimidusspeciescomplex)是生活于北半球高纬度区域的兔属物种。我们以该种组为模型,采用快速进化的mtDNA控制区序列对它们的系统地理结构进行比较研究。结果表明:雪兔种组以白令海峡为地理隔离存在显著的系变异为7.7%,变异范围从2.4%一11.5%。分子系统分析的最大简约树显示:来自乌孜别克斯坦的两个亚种(seertzoviandnikr枷ontana)首先发生遗传上的分化。之后盘羊祖先群体的扩散导致在中国某些地理区域可能有三个进化谱系的分化。盘羊祖先群体的扩散可能起始于亚洲大陆的西部通过中亚高原向南扩散。分布于中国的盘羊亚种中,阿尔金亚种(O.a.dalai-lamae)与西藏亚种(O.a.hodsoni)有着比蒙古亚种(aa.da附ino较近的系统进化关系。而来自乌孜别克斯坦的两个亚种(servertzoviandnigrimontana)与中国的盘羊亚种有着显著的遗传差异。

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A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.

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1. Plateau pikas Ochotona curzoniae are considered a pest species on the Tibetan Plateau because they compete with livestock for forage and their burrowing could contribute to soil erosion. The effectiveness of pest control programmes in Tibet has not been measured, and it is not known whether changes in livestock management have exacerbated problems with plateau pikas or compromised their control. This study measured the impact of control programmes and livestock management for forage conservation on populations of plateau pikas in alpine meadow in Naqu District, central Tibet, during 2004 and 2005.2. Current techniques for controlling plateau pikas in spring cause large reductions in abundance, but high density-dependent rates of increase result in no differences between treated and untreated populations by the following autumn. Rates of increase from spring to autumn are not influenced by standing plant biomass or concurrent grazing by yaks Bos grunniens and Tibetan sheep Ovis aries.3. In autumn there was significantly lower biomass outside fenced areas with year-round livestock grazing compared with inside fenced areas with equivalent or higher numbers of plateau pikas but predominantly winter grazing by livestock. Inside fenced areas, control of plateau pikas in spring produced no detectable effect on standing plant biomass at the end of the following summer compared with uncontrolled populations of plateau pikas.4. Regardless of their initial density, populations of plateau pikas declined rapidly over winter outside fenced areas where there was very low standing plant biomass in autumn. However, inside fenced areas with higher plant biomass in autumn, low-density populations of plateau pikas declined more slowly than high-density populations.5. Synthesis and applications. Current control programmes have limited effect because populations of plateau pikas can recover in one breeding season. There was no apparent increase in forage production in areas where plateau pikas were controlled. However, plateau pikas appear to benefit from changes in grazing management, with low-density populations declining less over winter inside fenced areas than elsewhere. It was not evident that control programmes are warranted or that they will improve the livelihoods of Tibetan herders.

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卡拉麦里山有蹄类自然保护区是世界著名的荒漠有蹄类自然保护区, 区内有蒙古野驴(E. hemionus)、鹅喉羚(G. subgutturosa)、盘羊(Ovis ammon)以及近期野放的普氏野马(E. przewalski)。经过多年有效保护和管理,区内蒙古野驴及鹅喉羚种群得到恢复并有较大增长。从2006年开始,我们在该保护区开展了蒙古野驴和鹅喉羚的食性构成、社群结构、种群密度、卧息及采食生境利用、季节性栖息地利用等方面的研究。主要结果如下: 采用粪样显微分析技术研究了蒙古野驴、鹅喉羚与家羊、家马和家骆驼3种家养动物春季、秋季和冬季食性组成及食物生态位。结果发现:(1) 该区域的蒙古野驴、鹅喉羚和家畜所采食的植物科数和种数都不相同,针茅、驼绒藜、蒿和梭梭在各自食谱中所占的比例不同, 但蒙古野驴、鹅喉羚和家畜主要采食针茅、驼绒藜、蒿和梭梭;(2) 春季、秋季和冬季这些野生与家养草食动物两两之间的食物生态位重叠均在0.8以上,最低为0.832(冬季:鹅喉羚和家马),最高达到0.986(秋季:蒙古野驴和家羊;秋季:家马和家羊)。五种有蹄类之间的食物生态位重叠度也达到了0.3以上。表明在卡拉麦里山有蹄类自然保护区,上述野生动物及季节性进入该自然保护区的家畜之间均存在食物竞争。冬季积雪深,食物短缺, 荒漠有蹄类易因冻饿及疾病等造成死亡。因此,应采取限制秋冬季进入该自然保护区家畜数量及调整放牧区域等保护管理措施,对该区域荒漠有蹄类实施有效保护。 对蒙古野驴和鹅喉羚的集群行为进行了初步研究。将鹅喉羚或蒙古野驴集群划分为雌性群、雄性群、母仔群、雌雄混群和独羚或独驴5种类型。共统计蒙古野驴556群次,计8235匹次。其中,雌雄混群223群次, 占40%, 为最多的集群类型;其余为雄性群(24%)、独驴(19%)、雌性群(11%)和母仔群(6% )。不同集群大小的比例差异极显著 (P=0.000)。其中2-30匹的集群占69%,独驴占18%,其余为13%。最大集群为266匹。除独驴外,其余4种集群类型的集群大小存在极显著差异。独驴作为一种特殊的集群类型,其占雄性个体的比例达63%,说明雄性个体比雌性更容易形成独驴。观察记录到鹅喉羚1286群次,计9148只次。其中,雌雄混群459群次, 占35%,为最多的集群类型;其余为独羚(18%)、母仔群(18%)、雄性群(17%)和雌性群(12%)。不同大小集群的比例差异极显著(P=0.000),其中2一15头的集群占73%, 16头以上集群占42%,独羚仅占3%,不同集群大小差异也极为显著(P=0.000)。除独羚外,其余4种集群类型的集群大小存在极显著差异。独羚作为一种特殊的集群类型,其雌性个体的比例占到55%,因此, 不能说明雄性比雌性更容易形成独羚。 分四个季节采用截线取样法,用DISTANCE5.0估计了蒙古野驴、鹅喉羚的密度和遇见率。根据DISTANCE5.0计算,该区域春季蒙古野驴种群密度为0.55±0.14匹/km2 (平均数±标准差,下同),夏季为0.60±0.13匹/km2,秋季为0.78±0.19匹/km2和冬季为0.54±0.14匹/km2。春季、夏季、秋季和冬季的鹅喉羚种群密度分别为1.14± 0.18头/km2,0.95±0.12头/km2,1.08±0.18头/km2和1.54±0.31头/km2。将这些结果与本区域不同时期及不同地域的蒙古野驴、鹅喉羚密度和遇见率数据进行了比较对比。截线取样法为研究干旱地区的有蹄类动物提供了一种标准方法,本研究结果为卡拉麦里自然保护区蒙古野驴和鹅喉羚的长期监测提供了基础数据。 采用样方法研究了鹅喉羚夏季和冬季卧息生境选择。夏季测定了49个卧迹样方,36个对照样方;冬季测定了75个卧迹样方,75个对照样方。研究发现,春季鹅喉羚主要选择平滩、下坡位和无坡位、海拔高度910米以上、与水源距离较远、远离道路、远离居民点、隐蔽级高、中低植被密度和中高草本密度的区域作为卧息生境;而冬季则主要选择山坡、阳坡和半阴半阳坡、中上坡位和下坡位、海拔900~1000m范围、离道路501~1000m以及大于2000m的距离、靠近居民点、中低隐蔽级、中厚度(1.1-3cm)雪深、中高植被密度和中高草本密度的区域作为卧息生境。主成分分析表明,卡拉麦里山鹅喉羚夏季季卧息样方前4个主成分的累积贡献率达到86.57%,第1主成分主要反映卧迹样方的植物密度、草本密度、针茅密度、至最近居民点距离、至永久水源最近距离和海拔。冬季该区域鹅喉羚卧息样方前4个主成分的累积贡献率达到73.88%,第1主成分主要反映卧迹样方的植物密度、草本密度、针茅密度和坡度。 通过设立样方研究了蒙古野驴的采食生境。研究发现,夏季和秋季两个季节蒙古野驴主要在平滩和山沟采食。集中在无坡向的平滩、1001m以上的海拔高度、与水源距离较近、远离道路、远离矿区等人类活动点、植被盖度高、草本盖度高、植物多样性高、草本多样性高(P<0.05)的区域采食。主成分分析表明,夏季影响蒙古野驴采食生境选择的环境因子是植物盖度、草本盖度、针茅盖度、植物密度、草本密度、针茅密度、植物种类、草本种类和禾本科种类。秋季影响蒙古野驴采食生境选择的环境因子是海拔、植物盖度、草本盖度、针茅盖度、植物密度、草本密度、针茅密度、植物种类、草本种类和禾本科种类。 利用卡山保护区不同季节野外种群调查数据,以3S技术为手段,评价了蒙古野驴和鹅喉羚季节性栖息地适宜性。首先把各季节蒙古野驴和鹅喉羚分布点图层,分别和固定水源点图层、道路图层、固定冬牧点图层和矿点图层进行叠加和距离查询,用Vanderploeg & Scavia’s选择指数(Ei*)分析了蒙古野驴和鹅喉羚季节性栖息地选择及其主要影响因素,建立了固定水源点、植被、道路、固定冬牧点和矿点对蒙古野驴和鹅喉羚栖息地影响强度的评价标准。通过缓冲区分析,分别研究了固定水源点、道路、固定冬牧点、矿点对蒙古野驴和鹅喉羚季节性栖息地的影响。通过缓冲区分析,综合研究了与人类活动有关的道路、固定冬牧点和矿点因子对蒙古野驴和鹅喉羚季节性栖息地的影响。最后将固定水源点、植被、道路、固定冬牧点和矿点等5个因子结合起来通过地图综合查询研究分析了这些因子对蒙古野驴和鹅喉羚季节性栖息地的综合影响,在固定水源点较适宜以上范围给出了该保护区蒙古野驴和鹅喉羚季节性不同适宜等级的生境面积。 我们建议采取以下积极措施来保护卡山保护区荒漠生态系统多样性以有效保护该区域内栖息的蒙古野驴和鹅喉羚:提高保护区周边社区政府的认识,提高公众参与自然资源和生物多样性保护的意识;加强水源地建设,积极采取飞播等措施,恢复植被,提高栖息生境质量;逐步限制进入卡拉麦里山越冬渡春的家畜数量;严格进入卡山保护区采矿制度,取缔非法矿业;加强草原围栏生态通道建设;与蒙古国合作建立跨国界的国际自然保护区;建立卡山自然保护区自然资源有偿使用机制;开展长期蒙古野驴和鹅喉羚种群监测。