红色角毛虫生理改组过程的研究

红色角毛虫在生理改组时,随着老纤毛器的瓦解,先后出现新的口器,额、腹、横棘毛,左、右缘棘毛和背触毛四个原基区,并发生原基区的分化、新结构的形成和定位。这种新、老结构的更替过程相似于同种纤毛虫正常形态发生时期纤毛器的演化过程,口围带改组时,新口围带原基在左列中腹棘毛左侧的范围形成,后来,随着老口围带的瓦解,它向前方移动并处于老口围带的右侧,并继续朝老口围带位置移动、替换老口围带。这不同于其他常见的腹毛类纤毛虫,生理改组时新口围带原基在瓦解着的老口围带的位置逐渐移动替换老口围带的情况。     

The Structure and Morphogenesis of the Ventral Ciliature in Paraurostyla hymenophora*

SYNOPSIS. The structure and morphogenesis of the ventral ciliature of Paraurostyla hymenophora (Stokes) are described. The oral primordium apparently originates in association with transverse cirrus #6, from which it migrates anteriorly simultaneous with kinetosomal proliferation. The primordium eventually forms an elongate ciliary field from which the future opisthe's fronto-ventro-transverse (FVT) and undulating membrane primordial fields arise. Concomitantly, the future proter's FVT primordial field is initiated by the disaggregation of frontal cirri #4, #5, and #6. Primordia then develop simultaneously within marginal and ventral cirral rows by a disaggregation of cirri within the respective rows, and do not give rise to new cirri until the FVT fields complete segregation into discrete cirri. Near the completion of cirral production from the FVT primordia, each ventral cirral primordium (VCP) forms the 2 rightmost transverse cirri. Segregation of new cirri within the marginal cirral primordia and VCP then occurs, eventually replacing all old cirri within their respective marginal and ventral cirral rows. At the end of cortical morphogenesis, all old ciliary organelles, with the exception of the adoral zone of membranelles, are either reorganized or replaced. These results suggest an evolutionary affinity between the ventral and marginal cirral rows and raise questions about the control of the developmental competence of individual primordia.     

卡龙游仆虫无性生殖期间的形态发生学研究：原生动物,纤毛虫

卡龙游仆虫为海洋中自由生纤毛虫,利用银染法对该种二分裂期间的形态发生学进行了初步的研究,其主要过程为：１．伴随大核改组带的出现和ＤＮＡ复制开始,口原基发生于老口围 方皮膜下一龛腔内,后由前至后组装成围口小膜而演化为后ＡＺＭ。老口围带及口侧膜在原位被被前仔虫继承;２．体棘毛场首先出现两组棘毛原基,其随后各自独立演化成９根前、后仔虫的额－腹－横棘毛;３．缘棘毛原基也为独立发生,初为单一,后断裂为二并分     

一种游仆虫无性分裂生殖的研究Ⅱ.无性分裂过程中皮层结构的形态发生

应用光学显微镜和扫描电子显微镜,观察到在一种游仆虫无性生殖周期中,新口围带发育时老口围带的更新、新波动膜原基的发生、棘毛原基发生的最早形态和背触毛发生等在其他种游仆虫中未见报道的现象。     

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.     

Morphological,Biometric, and Morphogenetic Comparison of Two Closely Related Species,Stylonychia vorax and S. pustulata (Ciliophora: Oxytrichidae)1

Differences in the morphology of Stylonychia vorax Stokes, 1885 and S. pustulata (Müller, 1786) Ehrenberg, 1838 recognizable in vivo are the shape, the ventral cirral pattern, the caudal cirri, and the mode of moving. The dorsal-bristle complexes are distinguishable by the length of dorsal kinety four and the spaces among the pairs of basal bodies. When the ranges of variation of different populations and clones are compared by biometric analyses, S. vorax shows a relatively stable cortical pattern whereas in S. pustulata the cortical elements are regulated depending on the size of the body and the number of adoral membranelles. In S. vorax morphogenesis begins with a proliferation of basal bodies close to the transverse cirri. In contrast, in S. pustulata, the oral primordium appears de novo between the left marginal row and the postoral cirri. All other morphogenetic events are the same for both species. In proters and opisthes the six anlagen of the frontal-ventral-transverse cirri are of different origin and evolve independently. Three anlagen of the opisthe separate from the oral primordium, two originate from the right, and one from the left postoral cirrus. Three anlagen of the proter evolve from the posteriormost cirrus in the frontal area, one from the parental undulating membranes, one from the buccal cirrus, and one from the cirrus below the buccal cirrus. The anlagen one to six generate one, three, three, three, four, and four cirri. The characteristic arrangement of the undulating membranes and the participation of only two postoral cirri in the formation of primordia provide features that distinguish between the often confused genera Oxytricha and Stylonychia.     

Stomatogenesis and Formation of Cirri in Fragments of Oxytricha fallax Stein

Of fragments involving a partial removal of the original adoral zone of membranelles (AZM), the monomacro-nucleate ones become reorganized monostomes resulting from a simple fusion of the remnant AZM to the oral primordium induced, and the binucleate ones become dividers by initiation of the oral primordium posteriorly from the posterior terminal of the remnant AZM. The cirral primordium in any fragment arises alongside its corresponding oral area. Weisz's idea of the dominance and inhibition of the original oral system extending over the oral primordium site is applicable in stomatogenesis of the present species. This application is found also in cirral formation.
In fragments from early stage dividers, a formed oral primordium is easily absorbed by influence of the intact original AZM. This event also occurs after complete removal of the AZM. Such results led to the hypothesis that the oral primordium in the normal divider may be formed under some stoma-togenic activation of the AZM followed by escape from inhibition also arising from the same source. Irrevocable furrow formation and irreversibility of the oral primordium in stomatogenesis occur in later stages of division. Nevertheless division in these stages is blocked when certain operations are performed, forming monsters possessing the AZM of the opisthe translocated to the side opposite to that of the proter. In other monsters obtained from a fusion of the AZM of the proter to that of the opisthe, division occurs belatedly, prior to which secondary oral and cirral primordia are produced.     

毛尾刺虫无性生殖周期中的形态和形态发生

利用蛋白银染色法研究了毛尾刺虫的形态及无性生殖周期中的形态发生,其过程为：（１）后仔虫口原基出现在左缘棘毛内侧深层,其内的毛基体组装成整齐排列的小膜并分化成新ＡＺＭ１,ＡＺＭ２和口侧膜,（２）前仔虫口原基出现在老仔虫ＡＺＭ２之前方深处,其随后发育成前仔虫的ＡＺＭ２口侧膜及ＡＺＭ１的一部分,并更新老结构的ＡＺＭ１中第７－１１片小膜,（３）额腹横棘毛原基为５列,分别以３：３：２：２：３方式分化最终产出     

Morphogenesis in the marine spirotrichous ciliate Apokeronopsis crassa (Claparède & Lachmann, 1858) n. comb. (Ciliophora: Stichotrichia), with the establishment of a new genus, Apokeronopsis n. g., and redefinition of the genus Thigmokeronopsis

Morphogenetic events during the division of the marine spirotrichous ciliate, Apokeronopsis crassa (Claparède & Lachmann 1858) n. comb. were investigated. Compared with members of the well-known genera Thigmokeronopsis, Uroleptopsis, and Pseudokeronopsis, A. crassa has one row of buccal cirri, high number of transverse cirri, clearly separated midventral rows, lacks thigmotactic cirri and a gap in adoral zone, its undulating membranes (UMs) anlage forms one cirrus and marginal rows and dorsal kineties form apokinetally during division. All these characteristics indicate that this organism represents a new taxon at the generic level, and hence a new genus is suggested, Apokeronopsis n. g. It is defined as thus: Pseudokeronopsidae with Pseudokeronopsis-like bicorona of frontal cirri and one marginal row on each side; one row of two or more buccal cirri in ordinary position; two midventral rows distinctly separated, hence of cirri that are not in a typical zig-zag pattern; high number of transverse cirri, caudal cirri absent, and frontoterminal cirri present; thigmotactic cirri absent, many macronuclear nodules fuse into many masses as well as marginal and dorsal kineties form apokinetally during morphogenesis. At the same time, the genus ThigmokeronopsisWicklow, 1981 is redefined, and one new combination, Apokeronopsis antarctica (Petz, 1995) n. comb. is proposed. The morphogenetic events of A. crassa are characterized as follows: (1) In the proter, the adoral zone of membranelles and UMs are completely renewed by the oral primordium. The UM anlage is formed apokinetally on the dorsal wall of the buccal cavity and is hence clearly separated from the frontoventral-transverse (FVT) cirral anlagen in the proter. (2) Frontoventral-transverse cirral anlagen are generated de novo in the outermost region of the cortex to the right of the old UMs. (3) A row of buccal cirri arises from FVT cirral streak I. (4) The marginal rows and dorsal kineties originate de novo in both dividers; no caudal cirri are formed. (5) The last FVT-streak contributes two frontoterminal cirri. (6) The many macronuclear nodules fuse into many masses (about 50 segments) during division, unlike a singular or branched mass as described in other urostylids.     

Divisional morphogenesis in the marine ciliate, Hemigastrostyla enigmatica (Dragesco & Dragesco-Kernéis, 1986) and redefinition of the genus Hemigastrostyla Song & Wilbert, 1997 (Protozoa, Ciliophora)

Morphogenetic events during the division of the marine hypotrichous ciliate, Hemigastrostyla enigmatica (Dragesco & Dragesco-Kernéis, 1986) Song & Wilbert, 1997 are described. The morphogenesis is characterized by:(1) 5 frontoventral-transverse cirral anlagen develop into 8 frontal, 5 ventral and 5 transverse cirri after Oxytricha-pattern;(2) there may be 6 FVT-anlagen in some individuals giving rise to more cirri which, however, will be resorbed after division;(3) anlage of the right marginal row at least in the opisthe occurs de novo right to the parental structures instead of within them;(4) according to the origin, the two extra ventral cirri right to transverse ones are not ventral or transverse cirri, which are from the retained old structure;(5) dorsal kineties originate from one group of DK-anlagen in both dividers with, very uniquely, an additional fragmentation of DK1, and(6) oral primordia will be formed in both dividing parts, from which the newly-built membranelles in the proter replace the posterior part of the parental AZM with a particular 'piecing together mode.Some features during the morphogenesis (e.g. variable number of cirral anlagen, presence of primary primordia, the mode of rebuilding of the proter's adoral zone of membranelles, origin of dorsal kineties and caudal cirri etc.) indicate that the genus Hemigastrostyla might present a intermediate form between oxytrichids and other related higher taxa. Based on our new observations, an improved diagnosis for genus Hemigastrostyla is given: marine or brackish water Oxytrichidae with slightly to conspicuously cephalized body shape; mostly 8–10 frontal, 5 ventral, 5 transverse and two to several extra ventral cirri to the right of the transverse ones, which are from the retained parental structure; caudal cirri present.     

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.     

Mirror-image configuration of the cortical pattern causes modifications in propagation of microtubular structures in the hypotrich ciliateParaurostyla weissei

Analysis or the development of microtubular structures in the mirror-image doublet cell lines of a hypotrich ciliate,Paraurostyla weissei, revealed several modifications in standard morphogenesis. Ciliary primordia can be formed without prior disaggregation of the preformed marginal cirri, on the left instead of the right hand side of an old row. Two or more overlapping streak segments may originate from disaggregating old marginal cirri, giving rise to two or three cirral rows. Inverted marginal cirri occasionally develop de novo and can be propagated clonally. Thus the modifications in developmental processes concern the positioning of primordia, the number of forming structures and the polarity of these structures. The microtubular triplets in the basal bodies of normal and inverted cirri do not differ, indicating that the large-scale reversal of the overall pattern has no effect on the assembly of microtubular triplets. The study indicates that the control of cytotactic propagation of compound microtubular structures is either modified or partially suppressed in a morphogenetic field where the positional values along one of the main cellular axes (lateral) have been reversed.     

Morphology and cell division of the oxytrichids Architricha indica nov. gen., nov. sp., and Histriculus histrio (Müller, 1773), Corliss, 1960 (Ciliophora, Hypotrichida)

The oxytrichid ciliate Architricha indica nov. gen., nov. sp., isolated from the river Yamuna, Delhi, shows a new combination of characters. It possesses a flexible body, 18 frontal-ventral-transverse (FVT) cirri, 3 right and 2 left marginal cirral rows, 6 dorsal bristle rows and 3 caudal cirri (CC). The FVT cirri arise from 6 primordia, which utilize 6 parental cirri in their origin as is typical of Oxytricha species. Multiple marginal rows (MMR) develop through 5 independent marginal primordia arising "within-row", 1 in each parental marginal row. All the 5 marginal rows are thus morphogenetically active. Such a mode of formation of MMR has not been recorded among oxytrichids and has necessitated separation of A. indica at the generic level. Histriculus, on the other hand, has well-known characteristics, viz. rigid body, confluent marginal rows and absence of CC. The morphogenesis of Histriculus histrio has been described by Berger and Foissner [1997. Cladistic relationships and generic characterization of oxytrichid hypotrichs (Protozoa, Ciliophora). Arch. Protistenkd. 148, 125-155]. Reinvestigation of very early stages of development revealed that (i) the FVT cirral primordia utilize kinetosomes from 5 parental FVT cirri, (ii) the primordium II of the proter is of a composite origin: kinetosomes from the oral primordium merge with the primordium II that originates from the buccal cirrus II/2 and (iii) the FVT primordia V and VI for the 2 daughter cells arise sequentially from the parental cirrus V/4. Thus, the genus Histriculus exhibits a new combination of characters with respect to the origin of FVT cirri, an additional pattern to be added to the known 6 patterns of FVT development in oxytrichids [Berger and Foissner, 1997; Berger, H., 1999. Monograph of the Oxytrichidae (Ciliophora, Hypotrichida), Kluwer Academic Publishers, Dordrecht/Boston/London].     

Morphogenesis of the marine spirotrichous ciliate, Trachelostyla pediculiformis (Cohn, 1866) (Ciliophora, Stichotrichia), with consideration of its phylogenetic position

The cortical development during binary fission of the relatively poorly known stichotrich ciliate, Trachelostyla pediculiformis (Cohn, 1866) Borror, 1972, found in coastal waters near Qingdao, China, was investigated using the protargol impregnation method. The morphogenetic process reveals some pretty unusual characteristics, which do not follow the Oxytricha-pattern: (1) the parental oral apparatus is entirely renewed from an oral primordium formed de novo in the proter; (2) in the proter, the parental undulating membranes are not involved in the formation of the newly formed oral primordium; both undulating membrane-anlagen (UM-anlage) and frontoventral-transverse cirral anlagen (FVT-anlagen) develop from the oral primordium in the proter; (3) the dorsal kineties (DK) are generated in a unique way, that is, in both dividers, two separate groups of DK-anlagen develop in the right- and left-most DK, generate all the DK and evolve to replace the old structures; (4) three caudal cirri are formed at the posterior ends of three right-most dorsal kinety anlagen; (5) eight frontal, five ventral and five transverse cirri are derived from six streaks, namely, the UM-anlage and 5 FVT-anlagen; the cirri are segregated from these anlagen in the pattern 1:3:3:3:4:4 (from left to right) in the Oxytricha mode. Based on both SSrRNA gene sequencing and morphogenetic data, the systematic positions of the genus Trachelostyla Borror, 1972 as well as the family Trachelostylidae Small and Lynn, 1985 are briefly analyzed. The results indicate that this genus/family could be a highly isolated lineage and might be ancestral to other well-known oxytrichids.     

Morphologie und Morphogenese des Bodenciliaten Oxytricha granulifera sp.n. (CiIiophora, Oxytrichidae)

Oxytricha granulifera sp.n. differs from other members of the genus by its subpellicular granules and the strongly shortened dorsal kinety 4. The overall pattern of the morphogenetic events is similar to that known from other Oxytrichidae. However, the oral primordium evolves de novo between the left marginal cirral row and the postoral cirri. The six anlagen of the frontoventral cirri are of different origin. Two anlagen of the proter evolve from parental frontal cirri, two from the opisthe, and one includes basal bodies of the proter and opisthe. Two anlagen of the opisthe evolve from the oral primordium, and three primordia originate from the postoral cirri. Frontal cirrus 1 evolves from the paroral membrane in the proter, and from the oral primordium and the anlagen of the frontoventral cirri in the opisthe. The genus Oxytricha can be subdivided into several groups with regard to the origin of its oral primordium and the development of the frontoventral cirri. The morphogenesis of the dorsal kineties in the Hypotrichida is reviewed. Seven different modes of origin are distinguished. We conclude that morphogenetic features cannot be used in the classification of the Hypotrichida at the generic level, because we have too little information to decide whether special morphogenetic features are important at the generic or species level.     

Cortical Pattern in Non-dividers, Dividers and Reorganizers of an Austrian Population of Paraurostyla weissei (Ciliophora, Hypotrichida): A Comparative Morphological and Biometrical Study

The morphology and the regulation of cortical pattern associated with the cell size, division, and reorganization of Paraurostyla weissei (Stein, 1859) were investigated. The ranges of variation of the Austrian, Polish, and American strains were compared by biometrical analyses. The Austrian population most frequently shows 4 frontal cirri in the anteriormost and 2 in the posterior row, 4 ventral rows, 8 transverse cirri, and 7 dorsal kineties. The oral primordium originates next to the postoral ventral row. The undulating membrane field and 3 frontal-ventral-transverse(FVT)-streaks for the opisthe develop as a result of the dispersion of the basal bodies of 1 or 2 cirri of the 1st ventral row. The farthest-right ventral row is of composite origin from 2 FVT-streaks. Three short dorsal bristle rows originating beside the right marginal row are a constant feature. In reorganizers the oral primordium characteristically possesses a group of kinetosomes extending toward the anterior right, fusing with the undulating membrane field. The development of dorsal primordia always starts in the 3rd dorsal kinety. These results provide important criteria for future species discrimination, if the examination of non-morphological characters supplies evidence that P. weissei is a complex of sibling species.     

变藓棘毛虫的形态学重描述及细胞发生学研究

通过活体观察和蛋白银染色法对采自青岛沙滩半咸水的变藓棘毛虫Sterkiella histriomuscorum(纤毛门, 腹毛目)进行了形态学及细胞发生学研究。该种群形态学与前人报道的土壤及淡水种群基本一致: 虫体近长椭圆形, 活体大小约(100-160) m (40-75) m; 无皮层颗粒; 2938片口小膜; 额棘毛3根; 额腹棘毛4根; 口后腹棘毛3根; 横前腹棘毛2根; 横棘毛3-5根; 左右缘棘毛列分别由17-23、20-24根棘毛组成; 6列背触毛; 2枚大核。其主要发生学特征如下: (1)老口围带完全保留, 老波动膜解体重建; 后仔虫口原基独立发生; (2)额腹横棘毛为5原基次级发生式, 部分原基来自老棘毛解体, 以2:3:3:4:4方式分化为新棘毛; (3)缘棘毛原基产生于老结构中, 并向两极延伸逐渐形成前后仔虫的新结构; (4)背触毛发生为典型Oxytricha模式; (5)大核在发生过程中完全融合。研究对首次在半咸水生境中发现的变藓棘毛虫种群进行了活体形态学和纤毛图式描述, 补充了显微照片、性状统计数据及发生过程的细节信息。       

四核舍太虫的细胞发生学与Helix E10-1二级结构分析

利用蛋白银染色技术,观察和研究海洋游仆虫-四核舍太虫Certesia quadrinucleata(纤毛门,游仆目)二分裂期间的形态发生学。其主要特征如下:(1)老口围带完全被前仔虫继承;(2)后仔虫口原基独立产生于皮膜深层;(3)老口侧膜参与前仔虫口侧膜原基形成,前后仔虫的口侧膜原基均发生于细胞表面, 向前贡献出第一根额腹棘毛;(4)额-腹-横棘毛以初级5原基模式产生, 且以"3:3:3:3:3"的方式分化出新的棘毛;(5)背触毛与左缘棘毛原基均来自老结构, 无尾棘毛产生。研究首次给出了背面纤毛器的发生图示,为进一步探讨舍太虫的系统地位提供了一份补足性的发生学基础资料。游仆目纤毛虫的核糖体小亚基基因HelixE10-1区域二级结构一共存在9种模式, 该区域序列长度的变异性揭示了游仆目纤毛虫在进化中可能处于比较特殊的地位。       

The Positioning of Ciliary Organelles in Hypotrich Ciliates*†

It is commonly observed in hypotrichs that new ciliary rudiments arise directly from or in close juxtaposition to certain pre-existing ciliary elements. Oral primordia often are initiated near specific cirri, cirral rudiments frequently arise as a result of the disaggregation of certain old cirri, and new dorsal ciliature is formed within pre-existing ciliary rows. In the first 2 situations it has been demonstrated experimentally that neither the old ciliature in question nor the specific cortical site marked by that ciliature is essential for the appearance of the new cirral rudiment. The experimental analysis done thus far suggests that the positions of oral and cirral primordia are determined by interacting gradients established in relation to certain reference points. The nature of the reference points is not fully elucidated; in some cases at least these points appear to be more closely related to topographic features of the cell than to specific pre-existing cortical structures. In the dorsal ciliary rows of Euplotes new ciliary units are formed usually and perhaps invariably in close proximity to old ones, and are generally oriented along the axis of the pre-existing row. The result is a tendency to perpetuate the preexisting row number across cell generations. Changes in row number, however, can occur as a result of occasional formation of new units at right angles to the row, a process that is much enhanced in certain homozygous segregants (basal body deficient). The optimal row number (stability range) as well as the number of ciliary units are under genic control. In addition, the spatial pattern of distribution of ciliary units among rows is invariant in all of the material examined. This pattern is presumed to result from an underlying field whose geometry is independent of both the number of units and the number of rows.