BEHAVIOR OF SECONDARY SPERMATOGONIA OF THE NEWT, CYNOPS PYRRHOGASTER, IN IN VITRO CULTURE

Several cell types migrated cut from small pieces of newt testes cultivated in vitro. Flat fibroblastic cells migrated out within a few days. Then, secondary spermatogonia, identified by the presence of germ cell-specific substances and by the shape and appearance of their nucleus and subcellular organelles, migrated out over the sheet of fibroblastic cells. Sertoli cells co-migrated with secondary spermatogonia, maintaining a similar cellular arrangement to that of testicular cells in vivo. Mitosis of secondary spermatogonia both in clusters and as single cells was frequent from the third day until about 2 weeks after inoculation. During mitosis, active and periodic rotation of chromosomes was observed. Identification of the cell types and studies on their behavior were performed by electron microscopy and phase contrast microscopy.     

SYNTHESIS OF RNA IN NEURONS OF THE HYPOGLOSSAL NERVE NUCLEUS, AFTER SECTION OF THE AXON, IN MICE

Synthesis of RNA in neurons of the hypoglossal nerve nucleus after axonal section was studied by means of [5-³H]uridine administration and radioautographic counting techniques in mice. The results of the experiments were evaluated by counts of silver grains over the nucleoplasm and cytoplasm of the neurons. RNA synthesis was greater in neurons after axonal section, and this increase was evident from 12 hr after the operation. The greatest increases in the operated side were observed in the 1st, 2nd and 3rd days after operation. In the 7th and 14th days RNA synthesis was still greater in the hypoglossal nucleus of the sectioned nerve but the difference in the control nucleus was not so striking. In the 30th day synthesis of RNA in left and right hypoglossal nuclei was comparable.     

中国云南人间鼠疫流行区蚤类宿主特异性及宿主选择(英文)

应用生态学中的生态位宽度及生态位重叠研究方法,对中国云南人间鼠疫流行区１１种蚤的宿主特异性及宿主选择进行了研究。宿主特异性用Ｌｅｖｉｎｓ生态位宽度进行测定。宿主选择用夹角余弦生态位重叠进行测定。结果表明：长形病蚤普洱亚种及印鼠客蚤的生态位宽度最窄、宿主特异性最高,近端远棒蚤二刺亚种及斯氏新蚤滇川亚种的生态位最宽、宿主特异性最低。印鼠客蚤（云南人间鼠疫流行区的主要鼠疫媒介）的优势宿主是黄胸鼠。印鼠客蚤较高的宿主特异性意味着该蚤可能主要在其优势宿主的不同个体间保存或传播鼠疫病原体。短突栉眼蚤及端凹栉眼蚤在宿主选择上较接近,而其它蚤种在宿主选择上差异较大。     

洱海三种生活型水生植物叶片中碳、氮与总酚含量的比较研究

植物体内的C、N和总酚是影响其被牧食和凋落物降解的重要因素,从而影响C和N在食物链的传递和生物地化循环。本研究测定了云南洱海3种生活型（挺水、沉水和浮叶）26种水生植物叶片中C、N和总酚含量以及C/N比率,并分析了它们与总酚的关系。结果表明:挺水植物叶片的C、N和总酚平均含量为448.08、39.30和24.70 mg/g,浮叶植物叶片的C、N和总酚平均含量为433.32、35.16和28.05 mg/g,沉水植物叶片的C、N和总酚平均含量为378.36、27.31和10.28 mg/g;总体上看,植物叶片C和N含量:挺水植物 浮叶植物 沉水植物;挺水和浮叶植物叶片的总酚含量差异不显著,且均远高于沉水植物叶片的总酚含量;26种植物叶片中C和N与总酚含量均呈显著正相关。在富营养化条件下,3种生活型植物所处生境的光照和CO2供给均差异显著,会对这些植物叶片的C、N和总酚含量有一定影响,此外由于应对生境中的胁迫（草食性昆虫、病原体及紫外线辐射等）压力以及自身的生长策略的不同也可能导致C、N和酚在三者中形成差异;通过对13种沉水植物叶片总酚含量比较,推测光叶眼子菜和微齿眼子菜较为适合作为洱海耐牧食恢复先锋物种;N与总酚正相关的关系可能在富营养化进程中加速湖泊沼泽化。     

四川黄龙沟森林植被中兰科植物群落优势种种间联结和相关分析

四川黄龙沟内分布着十分丰富的兰科植物(19属30余种),并且部分种类在沟内形成优势群落。目前尚不清楚在群落中这些兰科植物种之间作用关系。运用种间关联分析和相关分析对黄龙沟森林植被兰科植物群落中的24个优势种的种间关系进行了研究。两种分析方法得到的结果相近,表明黄龙沟优势兰科植物可以分为两组。一组包括无苞杓兰(Cypripedium bardolphianum)、黄花杓兰(C. flavum)、二叶红门兰(Orchis diantha)、广布红门兰(Orchis chusua)、少花虾脊兰(Calanthe delavayi)和西藏杓兰(C. tibeticum),主要分布在光线充足但又具有一定遮荫条件的环境中;另一组包括筒距兰(Tipularia szechuanica)、沼兰(Malaxis monophyllos)、珊瑚兰(Corallorhiza trifida)、小斑叶兰(Goodyera repens)、布袋兰(Calypso bulbosa)、小花舌唇兰(Platanthera minutiflora)和小叶对叶兰(Listera smithii),它们主要分布于荫蔽的环境中。这些兰科植物在组内大多呈现显著的正相关关系,组间大多呈现显著的负相关关系,说明黄龙沟兰科植物在资源利用方式上可能产生了分化。     

新疆古尔班通古特沙漠南部沙垄不同部位藻类的垂直分布特征

 通过2005和2006年夏季两次对新疆古尔班通古特沙漠南部荒漠土壤中藻类植物进行采样、培养、鉴定和生物量测定,分析了该区沙漠沙垄不同部位藻类物种组成、优势种和生物量的垂直变化。结果表明：1）在不同地貌部位的不同层次中,藻类的种类组成均有所差异。2）藻类优势物种主要集中在0～2 cm层次中,2 cm以下的土层中藻类细胞很少,绝大部分土层以具鞘微鞘藻(Microcoleus vaginatus)为第一优势种,有些部位的土层中第一优势种是伪双点颤藻(Oscillatoria pseudogeminata),如垄间低地和迎风坡的1～2 cm中。此外,大型集胞藻（Synechocystis crassa）、舟形藻 (Navicula sp.)、卵圆双眉藻(Amphora ovalis)数量也较多。3）除垄顶外,藻类生物量在其它3个部位不同层次的差异呈极显著水平（p<0.01）,生物量由表及里锐减;在同一土层,藻类生物量基本表现为垄间低地最高,迎风坡与背风坡居中, 垄顶最低,不同地貌部位对藻类生物量影响呈显著或极显著水平。     

安徽黄山青冈种群遗传结构的空间自相关分析

以黄山－青冈（Ｃyclobalanopsis glauca)种群为例,研究了种群内等位基因的空间格局,在种群内,大多数等位基因的Moran'sI数大于期望值,但只有两个等位基因存在显著的正空间自相关;如果考虑不同的无性系分株时,大多数等位基因在短距离内存在显著的空间自相关。相关图表明不同距离间隔,Moran'sI指数变化无规律,表明没有哪个进化因子起决定作用,但无性系繁殖在空间自相关中起重要作用,尤其是在近距离。     

福建红树林区大型藻类的生态学研究

主要研究中国福建省红树林区大型藻类分布、优势种的生物量和林冠下藻种的垂直分布特点。结果表明:福建红树林区的大型藻类有24属42种,其中蓝藻8属15种、红藻3属7种、绿藻13属20种。优势种中鹧鸪菜(Caloglossa leprieurii)和节附链藻(Catenella impudica)的生物量在6月分别为2.22～8.44g/m~2 DW和2.69g/m~2 DW,在12月分别为0.15～0.20g/m~2 DW和2.12g/m~2 DW。红树林中树干上附着生长的大型藻类的垂直分布自下而上可分成6个带:1.无隔藻(Vaucheria sp.)带;2、节附链藻带;3.侧枝鹧鸪菜-混合卷枝藻(Caloglossa ogasawaraensis-Bostrychia mixta)带;4.鹧鸪菜带;5.硬毛藻-岸生根枝藻(Chaetomorpha macrotona-Rhizoclonium riparium)带;6.绿球藻(Chlorococcum sp.)带。     

四川宜宾地区中草药植物资源

<正> 本区位于四川省南部,面积29,000平方公里,共有18个县市,人口900余万,是四川省第二大地区。 地势是西南高而东北低,为四川盆地与云贵高原的过渡地带。境内著名大山有屏山县的老君山,高2.020米,兴文县的先蜂山,高1,1750米;筠连县的大雪山,高1,772米;合江县的轿子山,高1,750米,古蔺县的斧头山,高1,835米。其余多为800—1,200米的中山山地及     

多项式逐步回归优化模型在浙江天童植物—土壤相关研究中的应用

本文应用多项式逐步回归分析法研究了浙江天童国家森林公园常绿阔叶林中20种植物与5种土壤因子(全氮、全磷、有机质、含水量、土壤PH值)之间的相关关系,筛选出对植物影响显著的控制因子,建立了植物—土壤环境因子相关的优化模型,并就土壤因子对植物种间关系的影响进行了讨论。作者认为该方法对于处理植物种与土壤因子之间的非线性相关情况是适用的。     

疑源类Tianzhushania在贵州瓮安震旦纪陡山沱组磷块岩中的发现

首次报道贵州瓮安地区震旦系陡山沱组磷块岩中的大型具刺凝源类Tianzhushania spinosa及其新种Tianzhushania tuberifera sp.nov.前者形态特征及内部结构与湖北峡尔地区震旦系陡山沱组隧石结核中发现的典型Tianzhushania spinosa 标本（硅化）完全相同,但多数未遭受重力挤压呈球形保存。新种特征明显,也呈球形保存,但内层表面具有明显瘤突,瘤突顶端向外延伸出单一或多条管状制,另外还探讨大型具刺疑源类Tianzhushania属的特征,已定种的地理分布,地层意义和亲缘关系。     

中心体蛋白Cenexin在大鼠精子发生过程中的表达特征

中心体蛋白Cenexin是成熟中心粒的唯一标志分子。为阐明中心粒在大鼠精子发生过程中的成熟以及功能,我们首先通过RT-PCR技术从大鼠睾丸组织中扩增出了Cenexin cDNA片段,原核表达重组蛋白后,用其免疫小鼠制备了高滴度的抗Cenexin的多克隆抗体,然后利用免疫荧光染色、Western Blot和半定量RT-PCR方法,研究了大鼠精子发生过程中Cenexin蛋白和基因的表达特征。结果显示Cenexin mRNA水平在精原细胞和精母细胞中较高,随后表达水平下降,而蛋白质分子在精原细胞到精子细胞中都定位于细胞的一个中心粒上,表示有成熟中心粒的存在,在长形精子细胞中该蛋白位于鞭毛的基体部。附睾的绝大多数成熟精子中Cenexin免疫染色消失。中心体蛋白Cenexin在精子变态期的表达变化可能与精子鞭毛形成的起始有关。     

喀麦隆塞玛岭地区溪流中的水生丝孢菌区系

Aquatic hyphomycetes on submerged fallen leaves and deadwoods have been numerously reported in fast running streams in temperate countries(Ingold,1976;Ingold,1979;Chauvet,1990;Barlocher & Rosset,1987;Barlocher et al.,1995;Descals et al.,1995).However,documented information is considerably limited in African countries(Ingold,1956;Dixon,1959;Le-John,1965;Ferreira et al.,1981),and unavailable in Cameroon,a country mostly covered with heavy tropical forests(Loung,1980).This paper is to present a list of aquatic and aeroaquatic hyphomycetes identified from foam samples collected in Cameroon during a two-year survey.     

THE ROLE OF PREDATION IN THE ECOLOGY OF THE RINGED SEAL IN BARROW STRAIT, NORTHWEST TERRITORIES, CANADA

Predation on ringed seals ( Phoca hispida ) was examined in Barrow Strait between March and May 1984 to 1986. Polar bears were the most important predator. Evidence of bear predation was observed at 18–30% of the ringed seal subnivean structures we located. Ten to 24% of predation attempts were successful, with pups making up 75% to 100% of the seals killed. Bears killed an average of 0.08 to 0.51 seals/km², which comprised 8 to 44% of the estimated annual pup production. Bears were successful on average in 11.3% of their attempts to kill pups hidden inside birth lairs. On southeast Baffin Island where snow was soft and pups were exposed, bears were successful in 33.5% of their attempts to kill a seal. Negative correlations were found between mean snow depth and predation by polar bears ( r = -0.896, P = 0.04, n = 5) in 1985, and between snow depth and the number of predation attempts ( r = -0.613, P = 0.02, n = 14) in 1986.