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| 1 | Further analyses of variation of ribosome DNA copy number and polymorphism in ciliates provide insights relevant to studies of both molecular ecology and phylogeny显示文摘Sequence-based approaches, such as analyses of ribosome DNA(rDNA) clone libraries and high-throughput amplicon sequencing, have been used extensively to infer evolutionary relationships and elucidate the biodiversity in microbial communities.However, recent studies demonstrate both r DNA copy number variation and intra-individual(intra-genomic) sequence variation in many organisms, which challenges the application of the rDNA-based surveys. In ciliates, an ecologically important clade of microbial eukaryotes, rDNA copy number and sequence variation are rarely studied. In the present study, we estimate the intraindividual small subunit rDNA(SSU r DNA) copy number and sequence variation in a wide range of taxa covering nine classes and 18 orders of the phylum Ciliophora. Our studies reveal that:(i) intra-individual sequence variation of SSU rDNA is ubiquitous in all groups of ciliates detected and the polymorphic level varies among taxa;(ii) there is a most common version of SSU rDNA sequence in each cell that is highly predominant and may represent the germline micronuclear template;(iii)compared with the most common version, other variant sequences differ in only 1–3 nucleotides, likely generated during macronuclear(somatic) amplification;(iv) the intra-cell sequence variation is unlikely to impact phylogenetic analyses;(v) the rDNA copy number in ciliates is highly variable, ranging from 103 to 106, with the highest record in Stentor roeselii. Overall,these analyses indicate the need for careful consideration of SSU r DNAvariation in analyses of the role of ciliates in ecosystems. | Yurui Wang Chundi Wang Yaohan Jiang Laura A.Katz Feng Gao Ying Yan | 2019 | Science China(Life Sciences)2019，62，2： | 7 |
| 2 | Timing and characteristics of nuclear events during conjugation and genomic exclusion in Paramecium multimicronucleatum显示文摘Ciliated protists are ideal material for studying the origin and evolution of sex,because of their nuclear dimorphism(containing both germline micronucleus and somatic macronucleus in the same cytoplasm),special sexual processes(conjugation and autogamy),and high diversity of mating-type systems.However,the study of sexual process is limited to only a few species,due to the difficulties in inducing or observing conjugation.In the present study,we investigate the conjugation process in Paramecium multimicronucleatum:(1)of the three prezygotic divisions,all micronuclei undergo the first two divisions(meiosis I,II),while a variable number of nuclei undergo the third division(mitosis);(2)the synkaryon divides three times after fertilization,giving rise to eight products that differentiate into four macronuclear anlagen and four micronuclei;(3)cells restore the vegetative stage after two successive cell fissions during which the macronuclear anlagen are distributed into daughter cells without division,while micronuclei divide mitotically;(4)the parental macronucleus begins to fragment following the first meiotic division and finally degenerates completely;(5)the entire process takes about 110 h,of which about 85 h are required for macronuclear development.In addition,we describe for the first time the process of genomic exclusion occurring between amicronucleate and micronucleate cells of P.multimicronucleatum,during which the micronucleate cell contributes a pronucleus to the amicronucleate cell,resulting in both exconjugants being homozygotes.These results provide new insights into the diversity of sexual processes and lay an important cytological basis for future in-depth studies of mating systems in ciliates. | Xue Zhang Xiaoteng Lu Yong Chi Yaohan Jiang Chundi Wang Saleh AAl‑Farraj Adriana Vallesi Feng Gao | 2022 | Marine Life Science & Technology2022，4，3： | 1 |
| 3 | Nuclear events during conjugation in the poorly studied model ciliate Paramecium jenningsi显示文摘Ciliated protists are highly differentiated unicellular eukaryotes that possess special sexual processes(conjugation and autogamy)that rely on their unique nuclear dimorphism,i.e.,the presence of both a germline micronucleus(MIC)and a somatic macronucleus(MAC)in a single cell.The sexual processes show a high diversity in different ciliates.To better understand the differentiation and evolution of sexual processes in closely related species,we investigated the nuclear events during conjugation in Paramecium jenningsi strain GZ,a poorly studied close relative of the well-known P.aurelia complex.The main results include:(1)the conjugation process takes about 48 h,including three prezygotic divisions(meiosis I,II,and mitosis)and three postzygotic divisions;(2)the MICs are dominated by the“parachute”phase at the prophase of meiosis I;(3)after meiosis II,a variable number of nuclei undergo the third prezygotic division,and the two products near the paroral cone become the genetically identical migratory and stationary pronuclei;(4)the synkaryon divides three times to form the MIC and the MAC anlagen,but only one nuclear product of the first postzygotic division completes the next two divisions;and(5)an extra cell division is required to complete the last step of conjugation,during which two MIC anlagen undergo mitotic division while two MAC anlagen are distributed between the daughter cells without division.The comparison of the nuclear events during conjugation in representatives of the class Oligohymenophorea reveals that usually there are three prezygotic divisions and a variable number of postzygotic divisions.However,the number of selected and differentiated nuclei after each division differs among species.This study provided a new model ciliate for further investigations of nuclear selection and differentiation as well as nuclear morphology during meiosis. | Xue Zhang Ruitao Gong Yaohan Jiang Xiaoteng Lu Chenyin Wu Lihan Wang Hongwei Ma Zhengxiang Zhang Weibo Song Khaled A.S.Al-Rasheid Adriana Vallesi Feng Gao | 2023 | Water Biology and Security2023，2，4： | 0 |
| 4 | Fluorescent sensing of anions based on excited state intramolecular proton transfer in N-(3-hydroxy-2- naphthamido)-N′-phenylthiourea显示文摘A neutral N-amidothiourea-based excited state intramolecular proton transfer (ESIPT) anion receptor bearing an o-hydroxynaphthamide fluorophore and a thiourea binding site, N-(3-hydroxy-2-naphthamide)-N’-phenylthiourea (1a), was designed and synthesized. Fluorescence and absorption response of 1a toward anions were assessed in acetonitrile. IR and NMR experiments indicated that the 'OH…O=C' intramolecular hydrogen bond (IHB) in 1a was weak so that it only exhibited the short-wavelength normal emission other than ESIPT fluorescence. Due to the high anion binding affinity of the N-amidothiourea binding site and the formation of a hydrogen binding network in the 1a-anion c omplex, 1a underwent structural change upon anion binding that strengthens the 'OH…O=C' IHB, leading to the ESIPT and the observation of the long-wavelength ESIPT emission whereas the normal fluorescence is quenched. On the basis of NMR and fluorescence titrations and control experiments with model compounds, a sensing mechanism of the anion-binding-induced ESIPT was proposed. | LI Zhao CHEN YaoHan JIANG YunBao | 2009 | Science China Chemistry2009，52，6： | 0 |
| 5 | The widely reported but poorly studied ciliate family Folliculinidae(Protozoa,Ciliophora,Heterotrichea):a revision with notes on its taxonomy,morphology and phylogenetic relationships显示文摘Ciliates of the heterotrich family Folliculinidae are widespread in various habitats and are distinguished by their transparent loricae of various shapes,conspicuous peristomial lobes,and dimorphic life cycles.They usually attach firmly to the surface of substrates,feed on bacteria and microalgae,and play a significant role in energy flow and material cycling in the microbial food web.However,little is known regarding their biodiversity and systematics.In this work,we establish the terminology of the family Folliculinidae and select six crucial features for genus recognition.Based on previous studies,we revise the classification of Folliculinidae,supply improved diagnoses for each of the 33 folliculinid genera,and provide a key to their identification.Moreover,phylogenetic analyses based on small subunit ribosomal DNA(SSU rDNA)sequences revealed that the family is monophyletic and comprises two subclades(subclades I II)which can be identified by the flexibility of their peristomial lobes and the sculpturing of their necks.Furthermore,we investigate the evolutionary relationships of folliculinids using the six chosen generic features. | Tingting Ye Yaohan Jiang Shuchang Chen Yixiang Xu Lifang Li Mann Kyoon Shin Xiangrui Chen | 2022 | Marine Life Science & Technology2022，4，4： | 0 |
| 6 | On four epibiotic peritrichous ciliates(Protozoa,Ciliophora)found in Lake Weishan Wetland:morphological and molecular data support the establishment of a new genus,Parapiosoma gen.nov.,and two new species显示文摘During a study on the diversity of ciliated protists in Lake Weishan Wetland,the largest wetland in northern China,four epibiotic sessilid peritrichs were isolated from aquatic host animals.Two of them,i.e.,Epistylis cambari Kellicott,1885 and Epistylis lwof Fauré-Fremiet,1943,were known species whereas the other two,i.e.,Parapiosoma typicum gen.nov.,sp.nov.and Orborhabdostyla gracilis sp.nov.,are new to science.The new genus Parapiosoma gen.nov.is characterized by its branched non-contractile stalk,everted peristomial lip,obconical macronucleus and transverse silverlines.Two species are assigned to the new genus,namely Parapiosoma typicum sp.nov.and Parapiosoma gasterostei(Fauré-Fremiet,1905)comb.nov.Morphologically,P.typicum sp.nov.is recognized by its goblet-shaped zooids,single-layered peristomial lip,dichotomously branched stalk,and infundibular polykinety 3(P3)containing three equal-length rows.Orborhabdostyla gracilis sp.nov.is characterized by its slender zooid,curved macronucleus,and three equal-length rows in infundibular P3.Improved diagnoses and redescriptions of E.cambari and E.lwof are provided including,for the frst time,data on the ciliature of E.cambari.Phylogenetic analyses based on SSU rDNA,ITS1-5.8S rDNA-ITS2,and LSU rDNA sequence data strongly support the assertion that the family Epistylididae comprises morphospecies with diferent evolutionary lineages and indicate that Parapiosoma gen.nov.may represent a new taxon at family level. | Tong Wu Ting Cheng Xiao Cao Yaohan Jiang Khaled A.S.Al-Rasheid Alan Warren Zhe Wang Borong Lu | 2023 | Marine Life Science & Technology2023，5，3： | 0 |
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