scholarly journals Morphology, Ontogeny and Molecular Phylogeny of a New Urostylid Ciliate, Bakuella (Pseudobakuella) Guangdongica n. sp. (Protista, Ciliophora, Hypotrichia) from Southern China

2020 ◽  
Author(s):  
Jingyi Wang ◽  
Jingbao Li ◽  
Yurui Wang ◽  
Saleh A. Al-Farraj ◽  
Chen Shao

Abstract Background: Spirotrich ciliates are one of the most diverse groupsin the phylum Ciliophora and are widely distributed in marine, freshwater, and terrestrial biotopes. Many nominal species are, however, poorly known and their systematic positions remain uncertain due to the lack of information concerning their infraciliature, morphogenesis, and gene sequences. In this paper, the morphology and morphogenesis of Bakuella (Pseudobakuella) guangdongica n. sp. were studied, in addition, genomic DNA was extracted in order to sequence the small subunit rDNA. Results: Bakuella (Pseudobakuella) guangdongica n. sp. is characterized by 150–225 µm in vivo; 35–42 adoral membranelles; three to five buccal, two frontoterminal and eight to 13 transverse + pretransverse cirri; midventral complex comprised of 10–20 midventral pairs and two midventral rows extending to transverse cirri; posterior part of marginal rows slightly overlapped; colorless cortical granules about 1 μm across, arranged in small groups; soil habitat. Its main ontogenetic features are: (1) in the proter, the parental adoral zone of membranelles is completely renewed by new structures; (2) in the opisthe, the oral primordium originates apokinetally, some old midventral cirri join the formation of frontoventral-transverse cirral anlagen; (3) the anlagen for marginal rows and dorsal kineties develop intrakinetally; and (4) the numerous macronuclear nodules fuse into a single mass before dividing. Phylogenetic analyses based on the SSU rDNA sequence suggests the non-monophyly of the genus Bakuella. Conclusions: The morphology, morphogenesis and molecular phylogeny of the new hypotrichous ciliate, Bakuella (Pseudobakuella) guangdongica n. sp. were studied, the phylogenetic analyses show that the Bakuella is polyphyletic in the SSU rDNA.

2015 ◽  
Vol 65 (Pt_9) ◽  
pp. 3216-3225 ◽  
Author(s):  
Xiaoteng Lu ◽  
Chen Shao ◽  
Yuhe Yu ◽  
Alan Warren ◽  
Jie Huang

The oxytrichid species Pleurotricha curdsi (Shi et al., 2002) Gupta et al., 2003, isolated from a tributary of the Yangtze River in the Mudong district of Chongqing, southern China, was reinvestigated with emphasis on its morphology, morphogenesis and small-subunit (SSU) rDNA-based phylogeny. Compared with three previously described populations, the Mudong population of P. curdsi is characterized by its large body size, 170–295 × 65–110 μm in vivo, and by having a variable number of right marginal rows, either two or three. Likewise, the number of right marginal rows anlagen (RMA) is also variable, i.e. usually two, but sometimes several small extra anlagen that give rise to the formation of the third row, are present to the left of the RMAs. We posit that the Mudong population is an intermediate form between the three previously described populations. Phylogenetic analyses based on the SSU rDNA sequence data show that all populations of P. curdsi cluster with the type species of the genus, Pleurotricha lanceolata, in a clade nested within the Oxytrichidae.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Gao ◽  
Chen Shao ◽  
Qiuyue Tang ◽  
Jingbao Li

The morphology and morphogenesis of Pseudosincirra longicirrata nov. gen. and nov. comb., isolated from southern China, were investigated with living observation and protargol staining. Our population is similar to the original population in living characteristics and ciliary patterns. The main determinable morphogenetic features of P. longicirrata nov. comb. are the presence of five frontoventral-transverse cirral anlagen (FVT-anlagen) and a dorsomarginal kinety anlage. According to the origin of FVT-anlagen IV and V in proter, it can be determined that P. longicirrata nov. comb. possesses two frontoventral rows and one right marginal row. Hence, a new genus, Pseudosincirra nov. gen., is proposed, and the diagnosis of P. longicirrata nov. comb. is improved. The new genus is diagnosed as follows: adoral zone of membranelles and undulating membranes is in a Gonostomum pattern; there are three enlarged frontal cirri, one buccal cirrus, and one parabuccal cirrus; postperistomial cirrus and transverse cirri are lacking; there are two more or less long frontoventral rows and one right and two or more left marginal rows; cirri within all rows very widely spaced; dorsal kinety pattern is of Urosomoida type, that is, three dorsal kineties and one dorsomarginal kinety; and caudal cirri are present. Phylogenetic analyses based on the small subunit ribosomal (SSU rDNA) sequence data indicate that P. longicirrata nov. comb. clusters with Deviata and Perisincirra. It is considered that Pseudosincirra nov. gen. and Perisincirra paucicirrata should be assigned to the family Deviatidae; fine cirri, and cirri within all rows being relatively widely spaced, should be considered as plesiomorphies of Deviatidae; and Deviatidae is closely related to Dorsomarginalia or Strongylidium–Hemiamphisiella–Pseudouroleptus.


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 1155-1164 ◽  
Author(s):  
Xumiao Chen ◽  
Miao Miao ◽  
Honggang Ma ◽  
Chen Shao ◽  
Khaled A. S. Al-Rasheid

A novel stichotrich ciliate, Strongylidium orientale sp. nov., was discovered from a mangrove river in Hong Kong, southern China, and its morphology was investigated through observations in vivo and after protargol impregnation. Cells are 80–120×35–50 µm in vivo and fusiform in shape, with rounded anterior and tapered posterior ends. It is characterized by its brackish habitat and by the presence of two types of cortical granules arranged irregularly throughout the cortex. Morphogenetic events of cell division and physiological reorganization are described. The main ontogenetic features were: (i) only the posterior portion of the parental adoral zone of membranelles was renewed by dedifferentiation of the old structures; (ii) the oral primordium in the opisthe occurred apokinetally; (iii) the left and right ventral rows originated intrakinetally and the final left ventral row was spliced from two cirri from the frontoventral cirral anlage, a short cirral row from the anlage for the right ventral row and a long cirral row which was formed from the whole anlage of the left ventral row; (iv) the marginal rows developed intrakinetally; (v) the dorsal kineties replicated entirely de novo and did not fragment; and (vi) the two macronuclear nodules fused into a mass and then divided. Based on small-subunit rRNA gene sequences, phylogenetic analyses showed a close relationship with its congener Strongylidium pseudocrassum and with the genus Pseudouroleptus.


2020 ◽  
Author(s):  
Jingyi Wang ◽  
Jingbao Li ◽  
Yurui Wang ◽  
Chen Shao

Abstract Background: Hypotrichia are a group with the most complex morphology and morphogenesis within the ciliated protists. The classification of the genus Holostichides is poorly understood particularly due to the lack of molecular data. Hence, the systematic relationship between this genus and other taxa in the subclass Hypotrichia remains unresolved. In this paper, the morphology and morphogenesis of Holostichides songi nov. spec. were studied, in addition, genomic DNA was extracted in order to sequence the small subunit rDNA. The main aims of this study were to document morphogenesis in H. songi nov. spec. and investigate the systematics of Holostichides based on morphology, morphogenetic, and molecular data.Results: A new bakuellid ciliate, Holostichides songi nov. spec. isolated from China, is investigated in terms of its morphology, ontogenesis, and molecular phylogenesis. It is characterized by size in vivo 150–180 µm × 45–60 µm; 27–46 macronuclear nodules; cortical granules dark, spherical, about 0.5 µm across, clustered in groups and then arranged longitudinally; three frontal cirri with one to four smaller cirri below the middle one, one buccal cirrus, 9–15 frontoterminal cirri, and midventral complex composed of five to eight cirral pairs and two long midventral rows. The main events during binary fission are as follows: (1) in the proter, the undulating membrane anlage is formed from both the dedifferentiation of old undulating membranes and the basal bodies developing de novo, and the posterior part of the parental adoral zone of membranelles is renewed by new structure formed from the oral primordium; (2) in the opisthe, the oral primordium is formed intrakinetally; (3) Besides the second frontal cirrus and buccal cirrus, the frontoventral-transverse cirral anlage II produces the extra one to four cirri. Phylogenetic analyses based on SSU rDNA sequence data suggest a close relationship between Holostichides songi nov. spec. and its congeners, indicating that the genus Holostichides is monophyletic.Conclusions: The new bakuellid ciliate, Holostichides songi nov. spec. was studied using standard methods. In addition, the monophyly of the genus Holostichides is well supported in the phylogenetic tree.


2010 ◽  
Vol 60 (1) ◽  
pp. 234-243 ◽  
Author(s):  
Xiangrui Chen ◽  
Shan Gao ◽  
Weibo Song ◽  
Khaled A. S. Al-Rasheid ◽  
Alan Warren ◽  
...  

Few studies using modern methods have been carried out on ciliated protozoa in tropical marine waters. In the present work, two hypotrichs, Parabirojimia multinucleata spec. nov. and Anteholosticha scutellum (Cohn, 1866) Berger, 2003, collected from Daya Bay in southern China, were investigated morphologically. P. multinucleata is distinguished by the following combination of characters: slender body, without a snout-like protrusion in the frontal field, and about 50 macronuclear nodules. The poorly known A. scutellum has never been investigated using modern methods; hence, a redescription is needed. During the present study, observations of specimens in vivo and following protargol impregnation revealed new information concerning structures such as the cortical granules and the infraciliature. A redescription and improved diagnosis are supplied based on the China population. The small-subunit (SSU) rRNA gene was sequenced for both organisms and comparisons with those of similar congeners clearly support the findings based on morphological studies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chen Shao ◽  
Qi Gao ◽  
Alan Warren ◽  
Jingyi Wang

The morphology and the regulation of cortical pattern associated with the cell size, division, and phylogenetic position of a new hypotrichous ciliate, Quadristicha subtropica n. sp. collected from a freshwater pond in southern China, were investigated. Quadristicha subtropica n. sp. is characterized as follows: size in vivo 60–115 μm × 25–45 μm; 19–21 adoral membranelles; buccal cirrus near anterior end of endoral and paroral; cirrus IV/3 at about level of buccal vertex; right marginal row begins ahead of buccal vertex; 11–16 right and 12–19 left marginal cirri; and dorsal cilia about 5 μm long. The basic morphogenetic process in Q. subtropica n. sp. is consistent with that of the type species, Quadristicha setigera. Phylogenetic analyses based on small subunit ribosomal DNA sequence data reveal that the systematic position of Q. subtropica n. sp. is rather unstable with low support values across the tree and the genus Quadristicha is not monophyletic.


2021 ◽  
Vol 7 ◽  
Author(s):  
Mingzhen Ma ◽  
Yuqing Li ◽  
Honggang Ma ◽  
Khaled A. S. Al-Rasheid ◽  
Alan Warren ◽  
...  

The morphology of four trachelocercid ciliates, Foissnerella typica gen. nov., spec. nov., Trachelolophos monocaryon (Dragesco, 1965) comb. nov. (original combination: Tracheloraphis monocaryonDragesco, 1965), Tracheloraphis katzae spec. nov., and Tracheloraphis colubis (Kahl, 1933) Xu et al., 2011 were studied in live and protargol-stained specimens. All samples were isolated from the intertidal zone of sandy beaches at Qingdao, China. The new genus Foissnerella can be distinguished from other trachelocercid genera mainly by the three circumoral kineties each composed of a row of dikinetids and the absence of a brosse or ciliary tuft in the oral cavity. The detailed investigation on the poorly described Tracheloraphis monocaryon (Dragesco, 1965) reveals that its oral infraciliature includes one uninterrupted circumoral kinety and a conspicuous ciliary tuft in the center of the oral cavity, which is consistent with the genus Trachelolophos rather than Tracheloraphis. Therefore, this species is transferred to Trachelolophos as Trachelolophos monocaryon (Dragesco, 1965) comb. nov. Tracheloraphis katzae spec. nov. can be recognized by the combination of its minute brownish cortical granules and 9–15 somatic kineties. The small subunit (SSU) rDNA of each species was sequenced for the first time. Phylogenetic analyses of the SSU rDNA show that Foissnerella typica gen. nov., spec. nov. clusters with Apotrachelocerca arenicola (Kahl, 1933) Xu et al., 2011 in a group that is sister to all other trachelocercids.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jiyang Ma ◽  
Tengyue Zhang ◽  
Weibo Song ◽  
Chen Shao

Ciliated protists (ciliates) are extremely diverse and play important ecological roles in almost all kinds of habitats. In this study, two new hypotrichs, Wilbertophrya sinica n. g. and n. sp. and Bakuella xianensis n. sp., from China are investigated. Wilbertophrya n. g. can be separated from related genera mainly by the combination of lacking a buccal cirrus, pretransverse cirri, and caudal cirri, while possessing frontoterminal cirri. Analyses based on morphological and molecular data confirm the validity of the species, W. sinica n. sp., which is characterized as follows: body 50–115 μm × 15–35 μm in vivo; midventral complex comprises four or five cirral pairs only and terminates above mid-body; three frontal, two frontoterminal cirri, and two to four transverse cirri; about 15 macronuclear nodules; colorless cortical granules sparsely distributed. Another new species, B. xianensis n. sp., was isolated from a freshwater wetland and is defined as follows: body 115–150 μm × 40–65 μm in vivo; about 70 macronuclear nodules; dark-brownish cortical granules in groups; midventral complex comprises 8–12 cirral pairs forming a row that terminates posteriorly in mid-body region and two or three short midventral rows that are continuous with the row of midventral pairs; three frontal, four to six frontoterminal, and three to five fine transverse cirri; three bipolar dorsal kineties. Phylogenetic analyses based on small subunit ribosomal DNA (SSU rDNA) sequence data suggest that the new genus Wilbertophrya n. g. belongs to an isolated clade, which might represent an undescribed taxon at the family level, whereas B. xianensis n. sp. groups with several congeners and members of other related genera are within the core urostylids.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Chen Shao ◽  
Khaled A. S. Al-Rasheid ◽  
...  

Abstract Background Ciliated protists, a huge assemblage of unicellular eukaryotes, are extremely diverse and play important ecological roles in most habitats where there is sufficient moisture for their survivals. Even though there is a growing recognition that these organisms are associated with many ecological or environmental processes, their biodiversity is poorly understood and many biotopes (e.g. soils in desert areas of Asia) remain largely unknown. Here we document an undescribed form found in sludge soil in a halt-desert inland of China. Investigations of its morphology, morphogenesis and molecular phylogeny indicate that it represents a new genus and new species, Parasincirra sinica n. g., n. sp. Results The new, monotypic genus Parasincirra n. g. is defined by having three frontal cirri, an amphisiellid median cirral row about the same length as the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The main morphogenetic features of the new taxon are: (1) frontoventral-transverse cirral anlagen II to VI are formed in a primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, although the posterior one (when formed) will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum-pattern; and (7) the macronuclear nodules fuse to form a single mass. The investigation of its molecular phylogeny inferred from Bayesian inference and Maximum likelihood analyses based on small subunit ribosomal DNA (SSU rDNA) sequence data, failed to reveal its exact systematic position, although species of related genera are generally assigned to the family Amphisiellidae Jankowski, 1979. Morphological and morphogenetic differences between the new taxon and Uroleptoides Wenzel, 1953, Parabistichella Jiang et al., 2013, and other amphisiellids clearly support the validity of Parasincirra as a new genus. The monophyly of the family Amphisiellidae is rejected by the AU test in this study. Conclusions The critical character of the family Amphisiellidae, i.e., the amphisiellid median cirral row, might result from convergent evolution in different taxa. Amphisiellidae are not monophyletic.


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 1197-1209 ◽  
Author(s):  
Xiangrui Chen ◽  
Chen Shao ◽  
Xihan Liu ◽  
Jie Huang ◽  
Khaled A. S. Al-Rasheid

This paper investigates the morphology, infraciliature and small-subunit (SSU) rRNA gene sequences of two hypotrichous ciliates, Neourostylopsis orientalis n. sp., and Protogastrostyla sterkii (Wallengren, 1900) n. comb. (basionym Gastrostyla sterkii), collected from coastal waters in southern China. Neourostylopsis orientalis n. sp. is diagnosed mainly by the arrangement of brownish cortical granules, the numbers of adoral membranelles and frontal and transverse cirri and the characteristics of its midventral cirral pairs. The SSU rRNA gene phylogeny strongly supports the establishment of the new genus Neourostylopsis n. gen., which is characterized mainly by the following features: frontal and transverse cirri clearly differentiated, buccal cirri present, two frontoterminal cirri, midventral complex composed of midventral pairs only and not exceeding the halfway point of the cell, more than one row of marginal cirri on each side which derive from individual anlagen within each parental row, caudal cirri lacking. Thus, two new combinations are required: Neourostylopsis songi (Lei et al., 2005) n. comb., and Neourostylopsis flavicana (Wang et al., 2011) n. comb. Additionally, improved diagnoses for both Metaurostylopsis and Apourostylopsis are supplied in this study. Protogastrostyla sterkii (Wallengren, 1900) n. comb. differs from the similar congener Protogastrostyla pulchra mainly in body shape, ratio of buccal field to body length in vivo and molecular data. Based on the present studies, we conclude that the estuarine population of P. pulchra collected by J. Gong and others [Gong et al., J Eukaryot Microbiol (2007) 54, 468–478] is a population of P. sterkii.


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