Effects of vertebrate herbivores and shrub characteristics on arthropod assemblages in a northern Arizona forest ecosystem

Large herbivores have potential to affect invertebrate community structure through numerous processes, but little work has been done to evaluate the relative importance of direct and indirect factors. In this study, we measured arthropod community assemblages on Ceanothus fendleri A. Gray (Fendler's ceanothus) plants that were growing inside and outside of 4-m² exclosures. We used univariate analyses and structural equation modeling (SEM) to evaluate relationships within this herbivore–plant–arthropod system in ponderosa pine (Pinus ponderosa Laws.) forests of northern Arizona, USA. Results showed that individual arthropod abundance, family diversity, family richness, and functional group richness were significantly greater on plots where C. fendleri plants were protected from large ungulate herbivores (e.g., mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus nelsoni)) than on unprotected plots in each of the three study years. Results also indicated the following: (1) arthropod abundance was significantly greater on protected plants than unprotected plants; (2) rarefaction curves suggested arthropod family richness was similar between protected and unprotected plants in two of the three years when scaled by number of individuals but the estimated total richness was consistently higher on protected plants; (3) arthropod abundance was directly affected by protection from herbivores, plant stem length, and number of flowers; (4) arthropod family richness was related to the number of individuals collected and affected by stem length. Results from this study illustrate that arthropod communities are directly affected by foraging vertebrate herbivores as well as indirectly affected through complex plant-mediated factors in this model system. Protection of preferred forage plants such as C. fendleri from ungulate herbivores can potentially increase diversity of arthropod assemblages in these forests, help conserve biological diversity, and enhance ecosystem restoration efforts.     

不同类型东北梅花鹿亲缘关系的研究

用聚丙烯酰胺凝胶电泳法测定140头东北梅花鹿5个类型的转铁蛋白（Tf）的多态性．Tf有6种表型,受TfA1、TfA2、TfB1、TfB2、TfC1、TfC2等6个复等位基因控制．比较梅花鹿5种类型间Tf基因频率,类型间有较大差异．利用同质度（H·I）、平均杂和性（H）和有效基因数（Ne）比较5种类型间的遗传变异性,双阳型和伊通型变异性较大,其次是东丰型、抚松型和龙潭型．根据基因频率计算遗传距离,并用类平均法进行聚类分析,结果表明,东丰型与抚松型、双阳型与伊通型的亲缘关系较近,龙潭型与其它4种类型有较大的分化．     

Radio-iodine treatment of hyperthyroid cats

Thirty-two elderly domestic shdrthaired cats (mean age 12.9 years) were treated with radioiodine (¹³¹I). The dose of ¹³¹I administered ranged from 39 mBq to 134 mBq. Twenty-eight cats became euthyroid after treatment, one became hypothyroid and three remained hyperthyrox-aemic. Two of the hyperthyroxaemic cats were successfully re-treated with ¹³¹I. Five cats died from concurrent diseases within one year of treatment. The administration of a dose of ¹³¹I selected by assessing the severity of the clinical signs, the size of the thyroid gland(s) and the serum level of thyroxine was an effective treatment for hyperthyroidism.     

东北梅花鹿卵泡发育过程中卵泡细胞超微结构的观察

为了进一步弄清东北梅花鹿卵泡细胞超微结构的变化规律,本研究用透射电镜、目镜测微尺和显微照相技术对各期卵泡中卵泡细胞的超微结构进行了观察,并按卵泡大小、颗粒细胞层数、透明带状况及卵泡腔是否出现,把卵泡分成4个阶段。结果表明：原始卵泡-卵泡细胞与卵母细胞已开始建立结构上的联系,卵泡细胞的形态变化也是适应卵泡发育的需要;初级卵泡-细胞器数量增加,结构变得清晰,卵泡细胞中出现厚壁小泡,可能是一种早期的脂滴;次级卵泡-卵泡突起穿过透明带,并出现有营养作用的脂滴和支持作用的微丝;三级卵泡-高尔基复合体发达,多与粗面内质网相贴,核糖体丰富,成簇分布,接近排卵的卵泡中卵泡细胞发生扩展等一系列结构上的变化将利于受精。     

Effects of bark stripping by sika deer, Cervus nippon, on wind damage to coniferous trees in subalpine forest of central Japan

We evaluated the effect of bark stripping by sika deer (Cervus nippon), and subsequent wood decay, on tree fall in a coniferous forest on Mt Ohdaigahara in central Japan from July to September 2006. This valuable primeval coniferous forest is declining because of bark stripping. Broken trunks of Abies homolepis and Picea jezoensis var. hondoensis had more serious decay and larger bark-stripping wounds on the trunk than standing trees, suggesting that bark stripping causes trunk decay and results in broken trunks and uprooting by typhoons.     

长白山马鹿的调查

马鹿在吉林省的分布区可划为 3个一级区和 8个二级区 ,适栖面积为 1.0 4× 10 6hm2 ,预计数量为 9853± 3586只 ,马鹿的平均寿命为 6.9岁。     

Impact of bark stripping by sika deer, Cervus nippon, on subalpine coniferous forests in central Japan

We investigated the effect of bark stripping by sika deer, Cervus nippon, on forest regeneration in subalpine coniferous forests on Mt. Ohdaigahara and in the Ohmine Mountains of central Japan. Bark stripping by sika deer occurred in five major tree species: Abies homolepis; Abies Veitchii; Tsuga diversifolia; Picea jezoensis var. hondoensis; and Chamaecyparis obtusa. The percentage of damaged trees on Mt. Ohdaigahara was higher than in the Ohmine Mountains, probably because of the higher deer density. On Mt. Ohdaigahara, the DBH distributions of stems for P. jezoensis var. hondoensis, A. homolepis, T. diversifolia andC. obtusa were bell-shaped with fewer smaller and larger trees. On the other hand, in the Ohmine Mountains the distributions for P. jezoensis var. hondoensis and A. Veitchii showed a reverse-J shaped with more smaller trees. Larger overstory conifers on Mt. Ohdaigahara were killed by bark stripping when 100% barked, although in the Ohmine Mountains ca. 50% of the trees survived even when 100% barked. After the disappearance of the overstory conifers on Mt. Ohdaigahara, the dwarf bamboo, Sasa nipponica, expanded into the forest floor due to changes in light reaching the forest floor. Since S. nipponica is the main forage of deer in this area, this increase caused a corresponding increase in the deer population, which in turn, could cause a further decline in the coniferous forests.     

梅花鹿18SrRNA基因的克隆和序列测定

对梅花鹿的18SrRNA基因片段进行了克隆测序,序列长度为1207bp,并且已被发送到Gene-bank上,其登录号是:AY 225108.     

梅花鹿γ 干扰素在不同真核细胞系中稳定表达的研究

提取经植物血凝素诱导培养的梅花鹿外周血淋巴细胞总RNA,应用RT PCR方法扩增出梅花鹿γ 干扰素成熟蛋白基因,经克隆测序表明与GenBank上发表的干扰素序列同源性为100%。将其重组到含有CMV增强子的真核表达载体质粒pCI neo上。利用磷酸钙介导转染法将重组载体质粒pCI neo CerIFN γ转染入中国仓鼠肾细胞(BHK 21)和牛肾细胞（MDBK）中,在G418抗性压力下进行筛选培养获得了稳定分泌表达的转染细胞系。通过Western blotting检测确定表达产物的相对分子质量分别为23、20、16 ku,与预测大小一致。本研究成果为进一步开发梅花鹿生物制品类治疗制剂奠定了基础。     

梅花鹿GHR基因完整编码区序列生物信息学分析

为了研究梅花鹿生长激素受体基因的结构和功能,从GenBank中下载梅花鹿、牛、山羊、猪、北极狐、大熊猫、人、猕猴、小鼠、大鼠、鸡、家鹅、绿头野鸭及金鱼的生长激素受体基因完整编码区及氨基酸序列,对梅花鹿与其他13个物种生长激素受体基因的完整编码区及其编码氨基酸序列进行相似性比对,并基于氨基酸序列构建系统进化树,利用BioEdit 7.0等软件对梅花鹿生长激素受体基因的碱基组成及其编码蛋白的理化性质和结构特征进行生物信息学分析。结果表明,梅花鹿与山羊、牛的生长激素受体基因氨基酸序列相似性较高,亲缘关系最近;梅花鹿生长激素受体基因完整编码区长度为1 905bp,编码634个氨基酸,A+T含量高于G+C;其编码的蛋白是一种分子质量为70.927 8ku、等电点为4.56的疏水性不稳定酸性蛋白;该蛋白含有1个信号肽,属于一种分泌型蛋白;存在1个强跨膜区、36个广泛磷酸化位点,二级结构元件以无规则卷曲为主。研究结果可为梅花鹿生长激素受体基因的进一步分析提供详细的生物信息学基础资料。