棘尾虫无小核镜像骈体的获得及其生殖行为的实验观察

用在分裂期进行显微手术的方法和在陈旧培养中诱导的方法,从贻贝棘尾虫天然无小核系S_(10)中获得了无小核镜像骈体。对骈体的各种生殖行为进行了观察,并用孚尔根和改进的黑色素染色技术揭示了它们的细胞学细节。发现在本文描述的无小核骈体和过去报告的有小核骈体之间,在二分裂和生理再生上没有显著区别。无小核骈体和正常单体S_7之间的接合命运则是多样化的。在630个这样的接合对中,有257对发生了真正的接合并形成接合后体;有153对接合不久包囊化;在其余的220对中,一个接合体吸收了另一个,变成营养型的单体和有小核的骈体。前者占总吸收者的96.8％,后者只占3.2％。对接合和吸收两种情况的细胞学事件进行了详细观察。无小核骈体中的两组细胞质和双套大核能吸引其配偶中的小核,形成自己新的双套大核胚基及小核胚基,在本文的讨论中受到充分注意。     

多节核棘尾虫无小核系虫体的初步研究

纤毛虫细胞具有大核和小核之分。多年来认为大核控制当代无性系细胞的全部代谢活动,小核只在有性生殖时起产生两性原核和受精的作用,从而更新无性系。近年来的研究证明,小核对当代无性系细胞的皮层形态及形态发生也起相当重要的作用。这此工作是在草履虫上(Ng等,1981,1984,1987)和贻贝棘尾虫上(史新柏等,1983,1990;Lu等,1989)完成的。但小核对大核的影响在任何纤毛虫上尚未见报道。笔者用所获得的新种多节核棘尾虫     

易动瘦尾虫的形态和核器二分裂过程

研究发现了易动瘦尾虫体腹面边缘各有缘棘毛一排,在各排缘棘毛的边上,又各有两排排列比缘棘毛疏松的棘毛,及它背面中央尚有一列背触毛。该虫是腹毛类纤毛虫中一种进化比较低等的类型,但其大、小核已明显分化。大核共进行了4次无丝分裂,小核共进行了3次分裂。     

旋唇纲系统发育基因组学分析支持瘦尾虫属归于散毛目

根据传统形态学特征的系统分类学研究,将瘦尾虫属(Uroleptus)归入尾柱目(Urostylida).但是,基于单基因和多基因联合的分子系统发育学分析支持瘦尾虫属与散毛目内部类群的亲缘关系更近.为进一步探讨旋唇纲(Spirotrichea)内部类群的系统发育关系以及瘦尾虫属的系统发育地位,我们对四种旋唇纲纤毛虫(澳大...     

沼泽瘦尾虫皮层纤毛器及其附属微管的观察

应用扫描电镜技术、荧光紫杉醇直接荧光标记显示了腹毛目纤毛虫沼泽瘦尾虫(Uroleptus limnetis)的细胞形态和皮层纤毛器的组成模式,以及皮层口围带、额腹横棘毛、左右缘棘毛等纤毛器微管和纤毛器附属微管的建构特征,可为进一步阐明瘦尾虫类纤毛虫的形态学及其系统发育研究提供基础资料。     

冠突伪尾柱虫接合过程中小核的形态发生作用

为查明有性生殖期间小核对形态发生的影响程度和范围 ,我们利用蛋白银染色对冠突伪尾柱虫不同交配型无小核体之间的接合过程进行了跟踪观察。结果表明 :无小核细胞的交配反应能力明显下降 ;接合双方第一次皮膜形态发生如常进行 ,但纤毛器原基分化往往出现异常 ;接合后体照常进入拟包囊阶段 ,但原有纤毛器多不从皮膜上消失 ;由于没有新核器形成 ,均不能启动第二次形态发生并于拟包囊早期解体死亡。因此 ,小核对于维持接合早期及第一次皮膜改组的正常进行具有某些明显作用 ,其衍生的大核原基对于启动后续的发育则是绝对必要的     

筛选冠突伪尾柱虫有小核细胞系和无小核细胞系饥饿期差异表达的ESTs

利用显微切割的方法建立大型腹毛目纤毛虫---冠突伪尾柱虫(Pseudourostyla cristata)的无小核细胞系,分别提取有小核和无小核细胞系的总RNA,用SMART-PCR方法直接合成dscDNA,进而运用抑制性消减杂交技术(Sup-pression subtractive hybridization,SSH)对冠突伪尾柱虫去小核前后的差异表达基因进行研究,构建了有与无小核细胞系在饥饿期差异表达基因的消减文库,随机挑取了284个克隆,应用cDNA阵列技术鉴定阳性克隆。将鉴定出的17个阳性克隆进行Blastx分析,结果表明17个EST(Expressed sequence tag)均可能与小核体功能密切相关,此为进一步阐明小核的遗传机理奠定了基础。       

多节核棘尾虫的发现及其与邻近属种的形态比较

黑龙江省帽儿山镇沼泽地生存着一种在体形和皮层形态上酷似贻贝棘尾虫的腹毛类纤毛虫,其大核呈多个结节相连的索状,这与传统的棘毛虫属的特征有别,但S期大核复制带两个仍在两端出现,这一点全似棘尾虫属,又鉴于腹毛类的其它属中也有大核结数目不同的种（Borror,1983),故单纯大核结节数目不同不应被视为属间判别,因此本文将此虫定为棘尾虫属一新种,名之为多节核棘尾虫,据此,棘尾虫属的传统鉴别特征在核形上也予以修正。     

冠窦伪尾柱虫接合过程中小核的形态发生作用

为查明有性生殖期间小核对形态发生的影响程度和范围,我们利用蛋白银染色对冠突伪尾柱虫不同交配型无小核体之间 的接合过程进行了跟踪观察。结果表明：无小核细胞的交配反应能力明显下降;接合双方第一次皮膜形态发生如常进行,但纤毛器原基分化往往出现异常;接合后体照常进入拟包囊阶段,但原有纤毛器多不从皮膜上消失。由于没有新核器形成,均不能启动第二次形态发生并于拟包囊早期解体死亡。因此,小核对于纤维接合早期及第一次皮膜改组的正常进行具有某些明显作用,其衍生的大核原基对于启动后续的发育则是绝对必要的。     

海洋尾丝虫无性生殖期间口器发生的再研究

利用蛋白银技术研究了海洋纤毛虫—海洋尾丝虫无性生殖期间的口器发生过程。结果显示其口器发生与已知的同属种类具相似的过程和形式。其口器发生及演化的基本模式可表示如下 :后仔虫的小膜 1、小膜 2来源于老口侧膜后段的增殖 ;后仔虫的口侧膜及盾片来源于老口侧膜前段的增殖 ;后仔虫的小膜 3来自于老口区盾片的增殖 ;前仔虫的口侧膜及盾片来源于老口侧膜 ,三片小膜在口器发生过程中被保留。文中根据现有的形态发生资料对尾丝虫科的系统关系进行了探讨     

Periacineta mexicana n. sp. (Ciliophora,Suctoria, Discophryida), Epizoic on Mexican Backswimmers of the Genus Buenoa (Insecta,Hemiptera, Notonectidae)

ABSTRACT. A new species of suctorian in the genus Periacineta, epibiotic on aquatic bugs (Hemiptera, Heteroptera, Nepomorpha), is described on the basis of morphological characteristics of the cell body, lorica, tentacular placement, and stalk, and its 18S rRNA partial sequence gene. Periacineta mexicana n. sp. is a loricate suctorian with elongate body and rounded apical region; tentacles are distributed randomly over apical region and not grouped into fascicles. Macronucleus in adult is elongate and located centrally. The suctorian usually forms closely aggregated pseudocolonies. We provide morphological data based on optical and scanning electron microscopy. A comparison with similar congeners, and emended diagnosis of the genus Periacineta also are provided. The ciliates were found attached to the first two pairs of legs of Mexican notonectids Buenoa pallens and Buenoa spp. (backswimmers).     

悬游双眉虫(原生动物,纤毛门)无性生殖期间的形态发生

应用蛋白银染色技术研究了悬游双眉虫青岛种群无性生殖期间皮层结构和核器的演化过程,其主要特征为:后仔虫口原基独立地出现于紧靠虫体左侧第一根横棘毛的皮层下小龛,其中毛基粒不参与其它棘毛原基的形成;老的口围带发生后半部的局部重建而非整个的由前仔虫简单继承;在前仔虫中,波动膜原基来自老结构的反分化,而在后仔虫中则来自口原基;所有棘毛原基均为独立发生并与老结构没有任何关系;在前仔虫中,口棘毛(即左侧第一根额棘毛)来自于波动膜的反分化,而在后仔虫中则为独立发生;背触毛列于老的结构当中产生,并由最右一列原基演化出3根尾棘毛;两大核片段的改组带从一端向另一端移动 ,并随着两者的融合而消失.文中同时对前人有关该属发生模式的若干存疑问题做了探讨 [动物学报 54(3):517-524,2008].     

Seven New Eimeria spp. (Protozoa,Coccidia) from Freshwater Fishes of Canada*

Seven new species of Eimeria are described and figured from the freshwater fishes of Ontario and Quebec, Canada. They are Eimeria catostomi sp. n. and E. fernandoae sp. n. from Catostomus commersoni (Lacépède), E. etheostomae sp. n. from Etheostoma exile (Girard), E. hoffmani sp. n. from Umbra limi (Kirtland), E. micropteri sp. n. from Micropterus dolomieui Lacépède E. pungitii sp. n. from Pungitius pungitius (Linnaeus), and E. salvelini sp. n. from Salvelinus fontinalis (Mitchill). Furthermore, 2 new host records and 2 new distribution records for North America are reported for E. anguillae Léger & Hollande, 1922 and E. truttae Léger & Hesse, 1919 respectively. Finally, morphologically similar oocysts found in various cyprinids are regarded as belonging to E. iroquoina Molnar & Fernando, 1974.     

Selenidium fauchaldi sp. n. and S. telepsavi (Stuart) comb. nov. (Protozoa,Apicomplexa), Gregarines from Polychaetes*

Gregarine Selenidium fauchaldi sp. n. is described from the intestinal lumen of the polychaete Phragmatopoma californica (Fewkes, 1889) in the intertidal zone of the Pacific Ocean on Santa Catalina Island, California. In addition, the new combination Selenidium telepsavi (Stuart, 1871) comb. nov. is introduced for the gregarine originally described as Monocystis telepsavi from the polychaete Telepsavus castarum in the Black Sea.     

Diplodinium (Ostracodinium) minorum sp. n., Ciliate from the Rumen of Domestic Sheep*

SYNOPSIS. Diplodinium (Ostracodinium) minorum sp. n., observed in rumen contents from several domestic sheep, resembles Diplodinium (O.) ypsilon and Diplodinium (O.) magnum. It differs from the latter 2 species primarily in the size and proportions of the body, size of the rectum and anus, and in the presence of a short right caudal lobe in many individuals. In the samples studied, D. (O.) minorum constituted from 0.06 to 0.67% of the total rumen ciliate population.     

Description of a marine peritrichous ciliate, Pseudovorticella sinensis n. sp. (Ciliophora, Peritrichia) from China

A new marine peritrich ciliate, Pseudovorticella sinensis n. sp. was isolated from a shrimp-farming pond in the littoral area of Qingdao, China. The morphology, infraciliature, and silverline system were studied based on living and silver-impregnated specimens. This species is characterized by (1) an elongated bell-shaped body that measures 50-60 x 35-45 microm in vivo, (2) one large, ventrally located contractile vacuole, and (3) a pellicle covered by a layer of transparent, cortical vesicles. The number of transverse silverlines from the peristomial area to the aboral ciliary wreath is 26-32, and from the aboral ciliary wreath to the scopula is 12-15. The stalk measures about 160-250 microm long x 5-6 microm wide. The spasmoneme has one row of conspicuous thecoplasmic granules, which are about 0.8 microm in diameter.     

Ultrastructural observations on the male gametes in Austrognathia sp. (Gnathostomulida,Bursovaginoidea)

The male gametes of the gnathostomulid bursovaginoid Austrognathia sp. were investigated by electron microscopy. All stages of sperm development can be observed in the single saccular male gonad, which is enclosed by a relatively thick basement membrane internally reinforced by thin smooth muscle cells. The spermatogonia are situated close to the testicular theca and produce generally separate primary spermatocytes. From secondary spermatocytes onwards, the nuclear envelope is no longer visible. The spermatids develop synchronously in groups of four, in contrast to arthropod and vertebrate spermatogenesis. A single, large nurse cell, or trophocyte, never observed previously, surrounds each spermatid; perhaps it represents an altered germ cell functioning in nutrition. The spermatid nucleus, initially ovoid, lengthens and takes on the shape of a mushroom head extending into a stalk. Three degrees of chromatin condensation are visible. Anteriorly, a palisade-shaped structure is present just over the highly heterochromatic nuclear zone and is considered to have an acrosome-like function. The outer sperm cytoplasm is characterized by a peripheral tubular labyrinth. Axonemal structures have never been found, but centriole-like structures are present among the medium-density chromatinic strands of the mushroom-like nucleus. No cortical microtubules are evident beneath the cell membrane. The external sperm morphology recalls that of nematode gametes, and some internal features are also similar. Phylogenetic considerations and hypotheses on sperm locomotion are proposed. J. Morphol. 237:165–176, 1998. © 1998 Wiley-Liss, Inc.     

Morphology of Three Species of Amphileptus (Protozoa,Ciliophora, Pleurostomatida) from the South China Sea,with Note on Phylogeny of A. dragescoi sp. n.

Two new and one problematic species of pleurostomatids, Amphileptus dragescoi sp. n., A. wilberti sp. n., and A. marinus from coastal areas of the South China Sea, are described based on observations of live and protargol‐impregnated specimens. Amphileptus dragescoi is different from its congeners by the presence of an apical group of extrusomes and the possession of 12–15 right and five left somatic kineties, two macronuclear nodules, and a single terminally positioned contractile vacuole. Amphileptus wilberti is diagnosed by oval or pyriform body, 15–19 right and seven or eight left somatic kineties, extrusomes arranged only in anterior portion of oral slit, usually three ventrally located contractile vacuoles, and two macronuclear nodules. Amphileptus marinus (Kahl, 1931) Song et al., 2004 is redescribed and its diagnosis is improved. One isolate which was misidentified as A. marinus by Song et al. (2004) is believed to represent an unknown form, named here as Amphileptus songi sp. n. Phylogenetic analyses of the SSU rDNA sequences indicate that the genus Amphileptus is paraphyletic, but its monophyly is not rejected by statistical tree topology tests.