Evolution of Phenotype and Mitochondrial Genome Reveals Limbless and Body-elongated Squamates may Change Their Energy Basis for Locomotion

Limb reduction in Squamata present the dramatic characteristic to focus and usually accompanied with particularly morphological modifications, impacting tremendous locomotion changing and might generate different energy requirement. Herein, we combined both morphological and mitochondrial genomic data to explore the evolution of phenotypic transformation and mitochondrial genome of limbless and body-elongated squamates. We collected phenotypic measurements of 503 individuals, representing limbed or limbless taxa across all major lineages in Squama ta to investiga te the morphological correla tions with limb-reduction. Furthermore, we provided the mitochondrial genome of the representative limbless and elongated species Dibamus bourreti(Angel, 1935) to detect selective constraints on limbless clades with published mitogenomes of other squa ma te reptiles. Our results evidenced tha t body elongation had certain negative relationship with limbreduction in Squamata lineage and Lacertilia lineage(R = –0.495, P 2.2 e-16; R= –0.332, P = 1.1 e-13, respectively), while tail length showed slight correlation in both clades(R = 0.156, P = 4.3 e-04; R= 0.192, P = 2.1 e-05, respectively). Besides, detection demonstrated that ATP6 has experienced accelerated evolution among limbless lineages, suggesting selective pressure on mitogenomes may play an essential role in energy disparity for locomotion of limbed and limbless squamates.     

藻蓝蛋白亚基细胞渗透性及对肿瘤细胞光敏作用的研究

目的:研究藻蓝蛋白亚基对SP2/0、S180、COS7、C6的最佳渗透条件及由其介导的PDT对肿瘤细胞的抑制作用。方法:采用柱层析方法从藻蓝蛋白样品中分离得到藻蓝蛋白亚基,通过荧光显微镜观察其在细胞内的渗透特性,并以He-Ne激光器为激发光源,MTT法检测藻蓝蛋白亚基光敏作用对肿瘤细胞生长的抑制作用。结果:藻蓝蛋白α、α/β亚基在75μg/mL浓度下可以在4 h时充分地进入细胞,并可以在细胞内稳定2 h以上;藻蓝蛋白中的α,β亚基稳定性和作用不相同,β亚基荧光性强但易于降解,由α亚基介导的PDT作用比α/βPDT作用强;100μg/mLα亚基介导的PDT对SP2/0和S180两种悬浮细胞的抑制率可分别达到78.6%和39.8%,强于贴壁细胞C6和COS7的29.2%和17.8%。结论:藻蓝蛋白α亚基在合适的渗透条件下表现出较强的光动力学抗肿瘤效果,且PDT效果与光敏剂浓度、照射剂量及细胞类型相关。     

海南羊山湿地的传粉网络及其季节动态

传粉网络是植物和传粉者之间形成的网状相互作用关系,为理解群落物种多样性形成与维持机制提供了全新的视角。湿地是典型的群落交错区,环境异质性与物种多样性都很高,传粉网络可能比草地和森林等生态系统具有更复杂的结构。该研究针对海南岛海口市南郊的羊山湿地,比较4个样地在旱季(5月)与雨季(8月)的传粉网络及其动态变化,揭示湿地生态系统的传粉网络结构特征以及在干湿季的变化规律。结果表明,羊山湿地传粉网络共有71种开花的植物, 131种传粉者,传粉网络呈现低连接度、高嵌套度、中等网络特化程度的结构特征。在季节动态方面, 4个样地旱季的植物与传粉者种类高于雨季;而传粉网络的连接度、嵌套度与网络特化程度没有明显的季节差异。白花鬼针草和水角等多个物种可同时在雨季和旱季开花,使得植物-传粉者的种间关系虽然存在季节变化,但传粉网络在旱季与雨季间的动态变化不大。总体而言,羊山湿地物种多样性较高,边缘效应较明显,传粉网络结构较稳定。     

惠州市景观格局空间分异特征的梯度分析

本文将景观指数、梯度分析和移动窗口法相结合,分析了惠州市景观格局的空间分异特征.以中心城区为起点,向外等距设置辐射状梯度带;同时结合研究区的特点,设置了4个不同方向的样带.综合运用景观指数粒度效应分析和土地面积变化评价指数模型,确定适合研究区的分析粒度;考虑到景观格局的各向异性,计算不同方向的半变异函数和相应的块基比,...     

山西省不同地区柴胡根部可培养内生真菌的多样性分析

为研究柴胡（Bupleurum chinense DC.）根部可培养内生真菌的多样性，分析山西省不同地区柴胡根部可培养内生真菌多样性的差异性，建立柴胡根部内生真菌库。本文以山西省不同产地的柴胡根为材料，采用传统植物组织平板分离法对柴胡根部可培养内生真菌进行分离培养和分子鉴定。从25个不同产地的柴胡样品根部中共分离培养得到705株真菌，经分子生物学鉴定，其中695株真菌归属为4门14纲23目32科55属119种。晋南地区的优势菌属为镰刀菌属（Fusarium, 32.18%）、亚隔孢壳属（Didymella, 15.96%）、曲霉属（Aspergillus, 8.24%）、异茎点霉属（Paraphoma, 6.91%）、茎点球属（Phoma, 5.32%）、链格孢属（Alternaria, 5.05%），晋北地区的优势菌属为镰刀菌属（31.66%）、曲霉属（15.36%）、链格孢属（9.09%）、亚隔孢壳属（8.15%）、异茎点霉属（7.52%），亚隔孢壳属、曲霉属、链格孢属等优势属的相对丰度差异较大；晋南地区的优势物种为Didymella bellidis（11.44%）、三线镰刀菌（Fusarium tricinctum, 7.98%）、腐皮镰刀菌（Fusarium solani, 7.45%）、锐顶镰孢菌（Fusarium acuminatum, 5.85%）、烟曲霉（Aspergillus fumigatus, 5.85%），晋北地区的优势物种为锐顶镰孢菌（14.11%）、烟曲霉（11.91%）、三线镰刀菌（9.40%）、菊异茎点霉（Paraphoma chrysanthemicola, 5.64%）、D. bellidis（5.64%）、链格孢菌（Alternaria alternata, 5.64%），D. bellidis、锐顶镰孢菌、烟曲霉等优势种的相对丰度差异较大。差异性分析表明晋南地区的生物多样性显著高于晋北地区，D. bellidis、锐顶镰孢菌、烟曲霉等优势种的相对丰度差异较大，为进一步研究柴胡根内生真菌相对丰度差异较大的物种及其不同菌株对柴胡皂苷积累的影响提供参考。     

Gene expression and molecular characterization of a thermostable trehalose phosphorylase fromThermoanaerobacter tengcongensis

A gene encoding the trehalose phosphorylase (TreP), which reversibly catalyzes trehalose degradation and synthesis from α-glucose-1-phosphate (α-Glc-1-P) and glucose, was cloned fromThermoanaerobacter tengcongensis and successfully expressed inEscherichia coli. The overexpressed TreP, with a molecular mass of approximately 90 kDa, was determined by SDS-PAGE. It catalyzes trehalose synthesis and degradation optimally at 70°C (for 30 min), with the optimum pHs at 6.0 and 7.0, respectively. It is highly thermostable, with a 77% residual activity after incubation at 50°C for 7 h. Under the optimum reaction conditions, 50 μg crude enzyme of the TreP is able to catalyze the synthesis of trehalose up to 11.6 mmol/L from 25 mmol/L α-Glc-1-P and 125 mmol/L glucose within 30 min, while only 1.5 mmol/L out of 250 mmol/L trehalose is degraded within the same time period. Dot blotting revealed that thetreP gene inT. tengcongensis was upregulated in response to salt stress but downregulated when trehalose was supplied. Both results indicate that the dominant function of theT. tengcongensis TreP is catalyzing trehalose synthesis but not degradation. Thus it might provide a novel route for industrial production of trehalose.     

Induced life cycle transition from holocycly to anholocycly of the Russian wheat aphid (Homoptera: Aphididae)

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),exists with holocyclic life cycle in Tacheng, Xinjiang in Northwest China. It produces males and oviparae to mate and oviposit for overwintering by eggs. Under laboratory conditions with 14 h/d photophase and temperature not lower than 15℃, RWA occurred in parthenogenesis and produced no males. The laboratory popu-lations of Russian wheat aphid, which were kept under natural conditions in fall by 15th, 49th and 81st generation while wild populations produced males and oviparae for mating, produced males and oviparae with their number decreased gradually, but viviparae and nymphs increased sequen-tially. As a result, it produced a small amount of oviparae and no males emerged in fields by 49 generations' reproduction in laboratory. After development of 81 generations, oviparae happened occasionally and no eggs occurred for overwintering instead of viviparae and nymphs. A hypothesis of RWA disastrous process was proposed. The life cycle of RWA can be changed from holocycly to anholocycly in its long-term spread and evolution. Anholocycly is more dangerous than holocycly to small grains for its strong adaptability and dispersal ability.     

猪圆环病毒II型ORF2基因在酵母中的高效分泌表达

为了建立一种简便的检测猪圆环病毒2型(PCV2)的方法,本实验将PCV2的ORF2基因片段整合到巴斯德毕赤酵母(Pichia pastoris)菌株X-33染色体上,构建了X-33(pPICZa-ORF2)重组工程菌.经甲醇诱导后,成功的表达出ORF2基因片段.经过Bradford 蛋白质总含量测定和凝胶薄层扫描结果表明,表达产物占重组工程菌培养上清总蛋白的58%,表达量可达47mg/ L.间接ELISA结果初步表明重组表达产物具有良好的抗原性,能够有效地区分PCV2型病毒标准阳性与阴性血清.     

高寒草甸不同生境类型植物群落的α及β多样性研究

用比较样地法调查了青藏高原东缘高寒草甸不同生境 阴坡、滩地、阳坡 植物群落的α及β多样性特征.结果表明?1各种α多样性指数均显示高寒草甸不同生境植物群落多样性顺序为?阴坡>滩地>阳坡.2各种α多样性指数之间均呈正相关,高寒草甸植物群落多样性更多地受均匀度的影响.3在高寒草甸,用物种盖度和地上生物量作为测定指标计算的群落α多样性所得的结果优于用株数作为测定指标计算的结果.4当生境由阴坡向滩地、由滩地向阳坡变化时,β多样性表现出由低到高,再由高到低的趋势,这表明在土壤湿度和日照时间适中时环境异质性大,物种替代速率比较快,β多样性较高.     

不同沙地生境下黄柳(Salix gordejevii)种群若干数量特征的比较研究

对分布于３种不同沙地生境（半固定沙丘、固定沙丘、丘间低地）黄柳灌丛的个体形态、生长和群体数量特征进行了比较研究,同时测定了灌丛下草本层植物种类组成及频率。结果显示：分布于丘间低地的黄柳灌丛当年枝平均长度增加缓慢,短枝条的比例较高,枝长频度分布（当年枝）峰值偏左,分枝也较多,叶片短而狭,长宽比大;与之相比,分布于半固定沙丘上的灌丛当年枝平均长度增加较快,长枝条比例较高,枝长频度分布趋于正态分布,分枝