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     

优美盾纤虫无性生殖期间的形态发生学研究：纤毛门：腹毛目

对优美盾纤虫二分裂期间的形态发生学进行了研究,其过程为：１）ＯＰ发于老ＡＺＭ的左后方皮膜深处其后一分为二并演化为仔虫的Ａ－ＡＺＭ及Ｂ－ＡＺＭ。在前仔虫老ＡＺ Ｍ及ＰＭ完全保留并被继承;２）前仔虫另行产生一原草,由其形成一额腹棘毛,在后后仔虫此棘毛严自ＯＰ腹侧。     

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].     

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。       

伍氏游仆虫二分裂和接合生殖期间的形态发生

用改进的银浸法和黑色素法研究了伍氏游仆虫在二分裂和接合期间的形态发生。在二分裂期间前仔虫继承亲体的口围带和口侧小膜。新伸缩泡开口起源于两组额腹横棘毛原基中的第5棘毛场。看清了接合期间两次形态发生的细节。在营养期口围带上见到的小膜第三排动体的骤然变换,已被证明起源于接合时第一次形态发生的不完整的口围带后端的保留。讨论了游仆虫与其它腹毛类在形态发生上的同源问题。     

腹毛目纤毛虫皮膜演化的一种特殊形式—卵圆急纤虫无性二分裂期间的形态发

对海洋纤毛虫卵圆急纤虫无性分裂过程中的形态发生了做了跟踪观察,结果表明,该种的皮膜演化表现了一系列在腹毛目种类中所罕见的特征;１．新老口围带有一临时性汇联为一的阶段;２．左右缘棘毛原基分步出现,即明显的不同步现象;３．大核的改组在细胞分裂开始前即已完成;４．本种后仔虫之棘毛原基的分化既非独立发生又非来自于老结构的反分化,而是紧靠口原基的一侧向外分衍并极可能是孤立地发展而成;５．老的波动膜在形态发生     

海洋纤毛虫--冠帆口虫的口器发生

对海洋盾纤目纤毛虫,冠帆口虫(Pleuronema coronatum)无性分裂期间口器的发生过程做了跟踪观察。结果显示其口器发生与已知的同属种普氏帆口虫具相似的过程。其口器发生及演化的基本模式可简述如下：老口区的三片小膜经历一个分化和移行过程;前仔虫的口侧膜来源于老口区的口侧膜;后仔虫的小膜1～3与口侧膜均来源于老的口侧膜;在口器发生过程中,前、后仔虫口侧膜的后端均形成一个相应的盾片区,其内的毛基粒在进入营养期之前被完全吸收[动物学报49(6)：829～834,2003]。     

冠突伪尾柱虫的腹皮层纤毛器微管胞器及其形态发生

应用荧光紫杉醇直接荧光标记和抗α-微管蛋白抗体免疫荧光标记方法,显示冠突伪尾柱虫腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成。口围带基部含小膜托架及与托架相联系的肋壁微管,其中领部小膜托架间由"∧"形微管相联接;额腹横棘毛基部含前纵微管束、后纵微管束、横微管束和周围微管束,其微管在不同棘毛基部的发达程度不一,其中两列中腹棘毛基部微管紧密联系成一条粗绳索样结构,且左、右中腹棘毛基部的横微管束定向相反;左、右缘棘毛基部含前纵微管束、后纵微管束和横微管束,其中横微管束不发达。与目前已知的腹毛目纤毛虫例如贻贝棘尾虫、魏氏拟尾柱虫的纤毛器基部微管相比较,冠突伪尾柱虫腹皮层纤毛器基部微管除具有腹毛目纤毛虫纤毛器基部微管的基本特征外,也具有一些特殊的组成模式。皮层纤毛器微管形态发生中,前仔虫口围带并非全部是由老口围带更新而来的,其老口围带只有翻领部发生更新,且翻领部与领部接续处有一小段老的翻领部小膜保留,领部的小膜保留,结果其领部小膜、接续处保留的小膜与更新的翻领部小膜三部分共同组成前仔虫的新口围带。在后仔虫口原基发生的位置,其邻近的老横棘毛没有变化,此时老的横棘毛或许能起到"参照点"或定位作用;各类纤毛器发生、分化过程中,处于非原基区的老额棘毛、横棘毛及左右缘棘毛在较长时间内均未见明显的变化。它们可能是在新结构形成时仍然起到运动作用继而逐渐失去功能而退化瓦解的。     

海洋纤毛虫黄色伪角毛虫无性生殖期间的形态发生

利用蛋白银染色技术研究了海洋纤毛虫———黄色伪角毛虫Pseudokeronopsisflava (Cohn ,186 6 )Wirns berger,Larsen&Uhlig ,1987无性生殖期间的细胞发生学。其主要特征为 :1)前仔虫口原基以独立发生的方式出现并独特地形成于口前庭右侧的皮层深处 ,由其对老口围带进行完全的更新 ;2 )老口器不参与新口器的形成 ,完全被吸收 ;3)前仔虫的额 -腹 -横棘毛原基同样为独立发生 ,老结构可能不参加其随后的发育 ;4 )后仔虫的口原基、波动膜原基及额 -腹 -横棘毛原基均来自最初排列无序的毛基粒发生场 ;5 )背触毛及缘棘毛的更新发生在老的结构中 ,并向前后延伸取代老结构 ;6 )在整个发生过程中 ,无大核融合现象。文中同时对该种所表现的发生学特征及系统学意义做了探讨     

暗尾丝虫的形态与形态发生研究

本工作采用Chatton-Lwoff氏银浸法及Wilbert氏蛋白银染色法研究了淡水纤毛虫暗尾丝虫Uronema nigricans(Muller,1786)的形态、核器、纤毛下器、银线系及详细的形态发生过程。结果显示其口器发生与已知的同属种类海洋尾丝虫具相似的过程及形式。其口器发生及演化的基本模式可表达成: 前仔虫:原口侧膜→口侧膜,盾片; 后仔虫:原口侧膜→口侧膜,第1小膜,第2小膜,盾片; 原盾片→第3小膜。 文中另外列表比较了本属与其它属的形态发生特征,并据此建立了一新科,拟梭虫科。     

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.     

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.     

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.     

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.     

An Analysis of the Formation of Ciliary Primordia in the Hypotrich Ciliate Urostyla weissei*

SYNOPSIS. The protargol technic was used in a study of the development of oral, cirral, and dorsal primordia of Urostyla weissei fixed during division, reorganization, and regeneration following transection at different levels. While the course of development is similar in all situations, differences were observed in the way in which some primordia are initiaily formed. The primordium of the new AZM always appears posterior to the old AZM. It develops into an entire new membranellar band in dividing cells and in opimers (posterior fragments from equatorial transections), while it eventually joins with a portion of the old AZM in reorganizers, promers (anterior fragments from equatorial transections) and “large opimers” (cells whose anterior tip has been cut off). The UM-primordium of proters is derived from disaggregation of the kinetosomes of the 2 old UM's, that of opisthes and opimers is formed “de novo” to the right of the AZM-primordium, while the UM-primordium of reorganizers, promers, and “large opimers” is of composite origin, partly “de novo” and partly from the old UM's. The UM primordium differentiates into the new UM's and the 1st frontal cirrus. The primordia of the remaining frontal, ventral, transversal (F-V-T) and marginal cirri originate as “streaks” of cilia, most of which are derived from re-alignment of the constituent cilia of certain pre-existing cirri. New cirri differendiate from the streaks, and replace the remaining old cirri. The streaks are formed similarly in all developmental situations, except for the 1st 3 F-V-T streaks. In proters, reorganizers, and promers, these originate from the posterior 3 frontal cirri, while in opisthes and opimers they are formed “de novo” to the right of the UM-primordium. In the “large opimers” these streaks are formed “de novo” behind the 1st 3 frontal cirri, in spite of the continued presence of these cirri at the anterior tip of the fragments. The site of formation of these streaks thus appears to be determined by an anteriorposterior gradient, rather than by any preformed cortical structure. The new dorsal bristle rows I to III develop from the proliferation of portions of the old rows, while rows IV and V originate from short kineties formed “de novo” on the right margin. New caudal cirri differentiate at the posterior ends of the new rows I to III. The numbers of ventral cirral rows and transversal cirri are variable; these variations are correlated, and related to variations in numbers of developing streaks. A survey of hypotrich developmental patterns revealed extensive parallels, especially in the sites of appearance of primordia. The primordium site appears to be a more constant feature of cortical development than is the “source” of ciliary units. It is concluded that sites of primordia are determined by cellular gradients, with competent preformed structures being utilized if they are appropriately positioned within these gradients.     

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.     

Morphogenetic characters of the model ciliate Euplotes vannus (Ciliophora,Spirotrichea): Notes on cortical pattern formation during conjugational and postconjugational reorganization

Ciliated protists represent a morphologically and genetically distinct group of single-celled eukaryotes which can reproduce asexually and sexually. Morphogenesis occurs in both asexual and sexual modes of reproduction which is of interest for researchers investigating cell differentiation, regeneration, systematics and evolution. However, studies of morphogenesis have concentrated almost entirely on the asexual mode. Here we use protargol staining to investigate the morphogenetic processes during sexual reproduction in the model species Euplotes vannus (Müller). The major events include: (1) two rounds of morphogenesis occur during sexual reproduction, i.e., conjugational and postconjugational reorganization; (2) in both processes the oral primordium is generated de novo in a pouch beneath the cortex; (3) the frontoventral-transverse cirri anlagen are formed de novo and fragment in a 3:3:3:3:2 pattern; (4) the leftmost cirrus and the paroral membrane do not change during conjugational morphogenesis, but reorganize de novo during postconjugational morphogenesis; (5) marginal cirral anlagen are formed de novo in both morphogenetic processes; (6) two or three caudal cirri are formed at the ends of the rightmost two or three old dorsal kineties; (7) the dorsal kineties are retained entirely. These results can serve as reference to investigate the morphogenetic events in the different stages of sexual reproduction.     

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.