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].     

Morphogenesis of Cyrtohymena tetracirrata (Ciliophora, Hypotrichia, Oxytrichidae) during binary fission

Morphogenesis during the binary fission of the oxytrichid Cyrtohymena tetracirrata was investigated using protargol silver impregnation. The main process reveals the following characteristics, which generally resemble those of its congeners: (1) the proter retains the parental adoral zone of membranelles in its entirety, while the old undulating membranes join to form the UM-anlage in the proter; (2) eight frontal, five ventral, and four transverse cirri are derived from six streaks, namely, the UM-anlage and five FVT-cirral anlagen, which are segregated in the pattern of 1:2:3:3:4:4 from these primordia from left to right, respectively; (3) the generation of the dorsal kineties is of typical Oxytricha-pattern; and (4) one caudal cirrus is formed at the posterior ends of the 1st, 2nd and 4th dorsal kinety anlagen.     

Ecology, Inhibitory Activity, and Morphogenesis of a Marine Antagonistic Bacterium Belonging to the Roseobacter Clade

Roseobacter strain 27-4 has been isolated from a turbot larval rearing unit and is capable of reducing mortality in turbot egg yolk sac larvae. Here, we demonstrate that the supernatant of Roseobacter 27-4 is lethal to the larval pathogens Vibrio anguillarum and Vibrio splendidus in a buffer system and inhibited their growth in marine broth. Liquid chromatography (LC) with both UV spectral detection and high-resolution mass spectrometry (HR-MS) identified the known antibacterial compound thiotropocin or its closely related precursor tropodithietic acid in the bioactive fractions. Antibacterial activity correlated with the appearance of a brownish pigment and was only formed in marine broth under static growth conditions. A thick biofilm of multicellular star-shaped aggregated cells formed at the air-liquid interface under static growth conditions. Here, the bioactive compound was the base peak in the LC-UV chromatograms of the extracts where it constituted 15% of the total peak area. Aerated conditions results in 10-fold-higher cell yield, however, cultures were nonpigmented, did not produce antibacterial activity, and grew as single cells. Production of antibacterial compounds may be quorum regulated, and we identified the acylated homoserine lactone (3-hydroxy-decanoyl homoserine lactone) from cultures of Roseobacter 27-4 using LC-HR-MS. The signal molecule was primarily detected in stagnant cultures. Roseobacter 27-4 grew between 10 and 30°C but died rapidly at 37°C. Also, the antibacterial compounds was sensitive to heat and was inactivated at 37°C in less than 2 days and at 25°C in 8 days. Using Roseobacter 27-4 as a probiotic culture will require that is be established in stagnant or adhered conditions and, due to the temperature sensitivity of the active compound, constant production must be ensured.     

Macronuclear Events and Some Morphogenetic Details During the Excystment of Onychodromus acuminatus (Ciliophora, Hypotrichia)

Light microscopy of stained (protargol, Feulgen, aceto-orcein, methyl green-pyronin) specimens of Onychodromus acuminatus during excystment shows that the macronucleus appears during the first hour as a warped ribbon with variable density and width and with sharpened ends. One extraordinary point that reaches the cortex is frequently seen in front of a small granule where the bundle of positioning fibers arises. The macronucleus returns to its previous form, with rounded edges, at the end of cortical morphogenesis, and later divides twice. Some details of cortical morphogenesis during the excystment process are discussed.     

Ontogenesis and Molecular Phylogeny of the Marine Ciliate Diophryopsis hystrix: Implications for the Systematics of the Diophrys-like Species (Ciliophora, Spirotrichea, Euplotida)

ABSTRACT. The cortical development of Diophryopsis hystrix , a small marine euplotid ciliate, was observed during binary division. The pattern of morphogenesis is generally similar to that of other Diophrys- like species, with the exception of the marginal cirrus, which develops in a unique manner in D. hystrix being formed from the posterior end of the dorsal kinety anlage, in a similar manner to the formation of the caudal cirri. In the small subunit (SS) rRNA gene sequence tree, Diophryopsis represents a distinct clade separate from Diophrys . Furthermore, our ontogenetic and SSrRNA gene sequence data both support the suggestion that the Diophrys complex is sister to Uronychia , and should be considered as a distinct subfamily within the family Uronychiidae, i.e. Diophryinae Jankowski, 1979, comprising Diophrys , Diophryopsis , and Paradiophrys . Diagnoses of the subfamilies Diophryinae and Uronychiinae are provided.     

The Cortical Morphogenetic Cycle Associated with Cell Division in Diophrys Dujardin, 1841 (Ciliophora,Hypotrichida)1

Morphogenesis of cell division was investigated in Diophrys scutum, D. oligothrix, and D. appendiculata utilizing both light microscopy of living and stained specimens and SEM of preserved specimens. The cortical morphogenetic pattern of Diophrys is similar to that of other members of the family Euplotidae. The opisthe oral primordium, which develops in a subsurface pouch, forms posterior to the parental buccal cavity. The proter inherits the parental adoral zone of membranelles (AZM) apparently unchanged. The endoral membrane forms to the right of the posterior end of the AZM in the proter, in association with the developing AZM in the opisthe. The paroral cirrus and membrane develop from a single streak that first appears along the right edge of the buccal cavity in the proter to the right of the developing buccal structures of the opisthe. Frontal and transverse cirri develop in both proter and opisthe from five separate cirral primordia that form to the right of the buccal cavity. Left marginal cirri do not develop in association with the corresponding parental structures. Kinetosomes formed within the opisthe oral primordium, or kinetosomes that were part of any parental ciliary structure, do not appear to become part of any developing paroral structures, frontal, transverse, or left marginal cirri. Speciation within the genus Diophrys and evolution of the family Euplotidae as they relate to the morphogenesis of cortical structure are discussed.     

Description of the Rare Marine Ciliate, Uronychia multicirrus Song, 1997 (Ciliophora; Euplotida) based on Morphology, Morphogenesis and SS rRNA Gene Sequence

ABSTRACT. A population of the marine euplotid ciliate, Uronychia multicirru s Song 1997 , found in the littoral zone of the Daya Bay, Guangdong, South China, was investigated using live observation and protargol impregnation method. This species is diagnosed by possessing a long row of ventral cirri, which has never been seen in all other known congeners. Divisional process, described based on protargol-impregnated specimens, is typical of the genus regarding its general pattern: (1) the oral primordia in both proter and opisthe develop de novo in two subcortical pouches, while the UM-anlage forms de novo (i.e. does not develop from the oral primordium); (2) five frontoventral-transverse (FVT)-cirral anlagen develop in a primary-mode on the cell surface, and almost all the cirri are derived from the FVT-anlagen, except the first frontal cirri, which are formed de novo in both dividers; (3) the species characteristic ventral row derives from the right-most FVT-anlage; (4) the parental structures do not take part in the construction of the marginal anlagen, and (5) the caudal cirri originate in the right-most two dorsal kineties in a multi-segmentation mode. The small subunit rRNA gene of U. multicirrus (GenBank accession number: EU267929) is 1,773 bp and differs by 0.9–1.41% from its closely related congeners.     

A Marine Euplotes (Ciliophora, Hypotrichida) with Reduced Number of Prezygotic Micronuclear Divisions

In contradistinction to the pattern of 3 prezygotic micronuclear divisions found in 10 species of Euplotes, a marine species resembling Euplotes crassus in structure, has only 2 divisions. This atypical division pattern was observed in all matings involving the 4 available mating types. The critical stages of the nuclear events are demonstrated by using special strains having the micronuclear DNA content and chromosome number only 1/2 the normal values. The employment of such strains facilitates differentiation between the stationary and migratory pronuclei in a given conjugant and determination of the times of conclusion of prezygotic divisions and of the pronuclear exchange.     

A Cover of Glass: First Report of Biomineralized Silicon in a Ciliate, Maryna umbrellata (Ciliophora: Colpodea)

ABSTRACT. Using hydrofluoric acid, scanning electron microscope-assisted X-ray microanalysis, and energy-filtered transmission electron microscopy, we present the first definite proof of biomineralized silicon [(SiO₂)] _n in a ciliophoran protist, Maryna umbrellata , a common inhabitant of ephemeral pools. In the trophic specimen, the amorphic silicon (glass) granules are accumulated in the anterior half of the body. When entering the dormant stage, most glass granules are excreted to form the surface cover of the globular resting cyst. Most likely, the silicon granules are synthesized in vesicles of the Golgi apparatus. First, nanospheres with a size of 20–40 nm are formed in a fibrous matrix; they grow to be spongious complexes, eventually becoming amorphous glass granules with an average size of 819 nm × 630 nm. In the transmission electron microscope, the silicon granules show the characteristic fracture pattern of glass known from many other silicon-bearing organisms. A literature survey suggests that silicon is very rare in ciliates. The fine structure and genesis of silicon granules in M. umbrellata are very similar to those of other organisms, including vascular plants and animals, indicating a common mechanism. Light perception and protection against mechanical stress and predators might be functions of the silicon granules in M. umbrellata . The palaeontological significance of glass cysts in ciliates is also discussed.     

Ellobiophrya conviva n. sp., a Commensal of Marine Ectoprocts,and a Revision of the Family Ellobiophryidae (Ciliophora,Peritricha)1

The sessiline peritrich Ellobiophrya conviva n. sp. is described from marine ectoprocts of the genus Bugula, the first report of an ellobiophryid on bryozoan hosts. The new species is distinguished from others of its genus by its different body proportions, size, host, and structure of the clasping holdfast (for which the new name cinctum is chosen). Ellobiophrya conviva has been found only on B. neritina and B. turrita and shows a marked seasonal cycle of abundance. The family Ellobiophryidae Chatton & Lwoff is revised on the basis of new information provided by E. conviva, with the single species of the genus Clausophrya removed to Ellobiophrya as E. oblida Naidenova & Zaika n. comb. The genus Caliperia Laird remains unchanged. The two genera of the revised family are distinguished from one another by differences in the structure of the cinctum. Hypotheses are advanced to explain the morphogenesis of the cinctum and the evolution of ellobiophryids from other peritrichs.     

Growth, Fine Structure and Cyst Formation of a Microbial Mat Ciliate: Pseudocohnilembus pusillus (Ciliophora, Scuticociliatida)

ABSTRACT Pseudocohnilembus species exhibit a polymorphic life cycle consisting of trophic cells, theronts, and cysts. Pseudocohnilembus pusillus isolated from the intertidal mats of Laguna Figueroa, Baja California Norte, Mexico, forms desiccation-resistant cysts in response to bacterial food depletion. This isolate is a euryhaline organism, able to grow at salinities from freshwater to 96 ppt total salinity and from pH 6–9. Electron micrographs show that oral and somatic cilia and kinetids are retained inside young cysts. Cyst walls are composed of a single layer (0.1 μm) of granular material. Under all conditions, as bacterial food was depleted, P. pusillus cells formed cysts, except for a small proportion (1–5%) that continued to swim. Changes in pH and salinity did not directly induce cyst formation. Salinity did greatly affect growth rate. Doubling times were shortest at 16 ppt salinity and at pH 7–8. Cyst formation occurred later in the growth cycle as more food bacteria were added. Additionally, ciliates grown in small culture volumes (10 ml) formed cysts sooner than cultures in larger volumes (100 ml), suggesting that crowding may influence cyst formation. Mature cysts may survive desiccation at least as long as one month at 37° C and for as long as one year at 20 ± 3° C. Although trophic cells did not survive desiccation or anoxia, encysted ciliates from liquid stationary phase cultures kept in anoxic seawater for one month excysted into swimming cells within 2.5 h after exposure to air. The adaptability of P. pusillus to extremes of salinity, pH, desiccation, and anoxia permits survival in its environmentally variable, microbial mat habitat.     

A redescription of the oxytrichid Tetmemena pustulata () and notes on morphogenesis in the marine urostylid Metaurostylopsis salina Lei et al., 2005 (Ciliophora,Hypotrichia)

Two hypotrichous ciliates from China were investigated. The common oxytrichid species Tetmemena pustulata (Müller, 1786) Eigner, 1999, isolated from the estuary of the Pearl River in southern China, was investigated with emphasis on its living morphology and infraciliature. Tetmemena pustulata is characterized as follows: body elliptical to obovoid in shape; 75–115 × 40–60 μm in vivo; two macronuclear nodules and two micronuclei; one contractile vacuole left of midline and somewhat ahead of midbody positioned; three frontal, four frontoventral, one buccal, three postoral ventral, two pretransverse ventral and five transverse cirri; cirrus III/2 ahead of level of cirrus IV/3; cirrus IV/2 arranged more anteriorly than cirrus V/4; transverse cirri not forming two distinct groups; three prolonged and widely separated caudal cirri; six dorsal kineties in Oxytricha-pattern with dorsal kineties 3 and 4 bipolar. The marine urostylid species Metaurostylopsis salina Li et al., 2005, isolated from an aquarium in Qingdao, northern China, was investigated with emphasis on its morphogenesis which is characterized by the de novo formation of the oral primordium in the proter and the development of the marginal rows from two anlagen that form within each parental structure separately in both dividers.     

Cortical structure in non-dividing and dividing Diophrys japonica spec. nov. (Ciliophora, Euplotida) with notes on morphological variation

The morphology and morphogenesis of Diophrys japonica spec. nov., isolated from the Mie Port, Nagasaki, Japan, were investigated from life and following impregnation with protargol. The new species is recognized by the following characters: Body elliptical in outline and slightly greyish to yellowish in color; size in vivo about 80-120 x 50-70 microm; pellicle flexible, with underlying granules densely arranged in lines; ciliature comprising about 30-46 adoral membranelles, 4-7 frontal, 1-4 ventral and 4-7 transverse cirri, always 1 left marginal and 3 caudal cirri, and 4 dorsal kineties; usually two macronuclear nodules; fragment kinety with 2-5 dikinetids; marine habitat. The main morphogenetic events are: (1) the opisthe's oral primordium develops de novo in a subsurface pouch near the left transverse cirri; (2) the proter retains the parental AZM except for reorganization of some proximal membranelles; (3) cirral anlagen for the frontal, ventral and transverse cirri in both dividers develop separately from the oral primordium or parental cirri, and are derived from the separation of primary primordia that originate de novo; (4) the anlagen for the left marginal cirrus and fragment kinety also form de novo and separately; (5) dorsal kinety anlagen occur within the parental structures at mid-body and posterior end of the cell, of which the right-most one contributes three caudal cirri from its posterior portion. Based on available ontogenetic data, the author proposes that the numbers of left marginal and caudal cirri can be regarded as reliable characters for species identification, while the numbers of frontal, ventral and transverse cirri are not consistent enough for species distinction. A key to the eleven adequately known species of Diophrys is presented.     

Establishment of a new hypotrichous genus,Heterotachysoma n. gen. and notes on the morphogenesis of Hemigastrostyla enigmatica (Ciliophora,Hypotrichia)

A marine hypotrich ciliate, Heterotachysoma multinucleatum (Gong and Choi, 2007) n. comb., found in coastal waters near Qingdao, China, was investigated. Heterotachysoma multinucleatum is characterized by its dorsal ciliature arranged in Gonostomum-pattern. Additionally, a new genus, Heterotachysoma n. gen., is established which is mainly characterized by: 18-cirri pattern; flexible body; three dorsal kineties with no dorsomarginal kineties nor kinety fragmentation; one right and one left row of marginal cirri; caudal cirri absent. The genus Tachysoma is redefined, and three new combinations, T. multinucleatum, T. ovatum and T. dragescoi, are proposed. The morphogenesis of Hemigastrostyla enigmatica (Dragesco and Dragesco-Kernéis, 1986) Song and Wilbert, 1997, is also described. Compared with that of its congeners, the differences are mainly in the dorsal ciliature: (1) the dorsal kinety anlagen are formed de novo in H. enigmatica (vs. intrakinetally in H. paraenigmatica and H. elongata); (2) the dorsal kineties anlagen develop in secondary mode in H. enigmatica (vs. primary mode in H. paraenigmatica); (3) the kinetal fragment anterior to the right marginal row in both filial product is absent in both H. enigmatica and H. elongata (vs. present in H. paraenigmatica). These findings suggest that morphogenesis is not uniform among members of the genus Hemigastrostyla.     

Phylogeny and Systematic Position of Zosterodasys (Ciliophora, Synhymeniida): A Combined Analysis of Ciliate Relationships Using Morphological and Molecular Data

ABSTRACT. The Synhymeniida is characterized both by a band of somatic dikinetids, the synhymenium, extending across the surface of the cell and by a ventral cell mouth lacking specialized feeding cilia but subtended by a well-developed cyrtos. The synhymeniids have been hypothesized to be members of the class Nassophorea but our previous ultrastructural study of the synhymeniid genus Zosterodasys did not show any clear synapomorphies that would permit definitive placement in the Nassophorea or as a sister taxon to any of the other ciliate groups possessing a cyrtos. In the present study, simultaneous analysis of morphological and small subunit rDNA molecular data indicates that the Synhymeniida are sister to the class Phyllopharyngea and that this clade is, in turn, sister to the remaining Nassophorea, although this result is sensitive to dataset inclusion and alignment parameters. While this suggests that taxa with a ventral cyrtos might be united into a named taxon (e.g. resurrecting the Hypostomata), additional data are needed to reach a definitive conclusion.     

膜状急纤虫(原生动物,纤毛门)休眠期包囊与营养期细胞同工酶组成和活性比较

应用聚丙烯酰胺凝胶电泳酶化学技术显示,腹毛目纤毛虫膜状急纤虫（Tachysoma pellionella）休眠包囊和营养细胞中乳酸脱氢酶、α磷酸甘油脱氢酶、醇脱氢酶、细胞色素氧化酶、葡萄糖-6-磷酸脱氢酶、过氧化物酶和过氧化氢酶等7种同工酶的酶谱组成有明显差异,并且在休眠包囊中其同工酶成分少、活性低,部分同工酶酶谱表现出趋于简单的趋势。ATP酶、苹果酸脱氢酶和谷氨酸脱氢酶等3种同工酶在休眠包囊与营养细胞中有相同的酶谱,但在休眠期包囊酶的活性低于营养期细胞。     

Morphology and molecular phylogeny of two new brackish-water species of Amphisiella (Ciliophora,Hypotrichia), with notes on morphogenesis

Two new species of the taxonomically confused genus Amphisiella were isolated from brackish-water habitats in southern China, and their morphology and morphogenesis were investigated. The genes coding for small subunit (SSU) rRNA were sequenced in each species and included in a phylogenetic analysis with all data available from nominal species of Amphisiella and related hypotrichs. Both new species are diagnosed by an elongate body shape, yellow-brown/grey-brown cell color, one kind of cortical granule, and two macronuclear nodules. The cortical granules in A. pulchra sp. n. are grouped in small clusters which are irregularly distributed both ventrally and dorsally; in A. candida sp. n., they are irregularly and sparsely distributed ventrally and form longitudinal stripes dorsally. The ontogenetic processes of both species show similarities to those of other congeners. Phylogenetic trees based on SSU rRNA gene sequences suggest that the family Amphisiellidae is a paraphyletic assemblage. The results further demonstrate that two isolates identified as Amphisiella annulata (DQ832260 and GU170843) are very likely cryptic species, and a sequence identified as A. milnei (DQ845293) may belong to a genus other than Amphisiella.     

Uronychia transfuga (O. F. Müller, 1786) Stein, 1859 (Ciliophora, Hypotrichia, Uronychiidae): Cortical Structure and Morphogenesis during Division

Morphogenesis of cell division was investigated in Uronychia transfuga utilizing both light microscopy of living and stained specimens and SEM of preserved specimens. The cortical morphogenetic pattern of Uronychia is similar in several respects to that of the members of the family Euplotidae. These features include: the de novo development of the opisthe oral primordium in a subcortical pouch; the development of frontoventral and transverse cirri for both the proter and opisthe from 5 cirral primordia that form de novo within a single latitudinal developmental zone; and the absence of right marginal cirri. The members of the genus Uronychia also show a number of unique characteristics: development of a proter oral primordium that causes partial replacement of the parental adoral zone of oral polykinetids during development of the proter; a large oral membrane that is divided into a right and left component; large caudal cirri that bend to the left; and dorsal kineties comprised of closely set paired-kinetosome kinetids. When compared to the other euplotid-like ciliates, these unique features support the placement of the genus Uronychia in a separate family, Uronychiidae.