Ciliates are important unicellular organisms in the studies of biomolecules,genetics,and evolution.Euplotids are a highly diversified and widely distributed group.The morphology of two euplotids,Euplotes dominicanus a...Ciliates are important unicellular organisms in the studies of biomolecules,genetics,and evolution.Euplotids are a highly diversified and widely distributed group.The morphology of two euplotids,Euplotes dominicanus and E.parkei,isolated from the Yangtze River Estuary,China,were investigated based on live observation,protargol-,and Chatton-Lwoff staining methods.The Chinese population of E.dominicanus resembles the original abyssal population except for having two caudal cirri and seven dorsolateral kineties.The Chinese population of E.parkei corresponds well with the original description in size,having eight frontoventral cirri,two marginal cirri,and a double-eurystomus dorsal silverline system.The diagnoses were improved by incorporating newly obtained data,detailed illustrations,and photomicrographs were supplemented.Euplotes parkei sensu needs to be reinvestigated.Phylogenetic analyses based on SSU rRNA gene sequence data confirmed the branching position of the two taxa within the genus Euplotes.The geographical distribution of the genus Euplotes in China was also briefly reviewed,and further exploration is needed in the brackish habitat,particularly focusing on the estuary zone.展开更多
Ciliated protists are one of the most diverse and highly differentiated group among unicellular organisms.Doublets occur in ciliates when two cells fuse into a single individual.Doublets contain two major cellular com...Ciliated protists are one of the most diverse and highly differentiated group among unicellular organisms.Doublets occur in ciliates when two cells fuse into a single individual.Doublets contain two major cellular components(either cell in a doublet)and have traditionally been considered as developmental anomalies.Nevertheless,doublets can divide or even conjugate effectively,which may represent dispersal forms of the life stages.In addition,morphogenesis,as an important process in the life cycle,will provide important insights into the complex differentiation mechanism and various physiological phenomena.However,morphogenetic studies focusing on doublets of ciliates are very limited,which has become an obstacle to understand their complete life history.Here we isolated a doublet strain from the marine species Euplotes vannus(Müller,1786)Diesing,1850 and investigated its morphogenetic events during asexual reproduction.Our results indicate that:(1)the opisthe’s oral primordium develops de novo beneath the cortex;(2)the frontoventral and transverse cirral anlagen,cirrus I/1,and marginal anlagen in both dividers develop de novo separately;(3)the dorsal kinety anlagen,the three rightmost ones of which produce three caudal cirri for the proter,occur within the parental structures in the mid-body region;(4)the opisthe acquires two caudal cirri,one from the end of each two rightmost kineties;and(5)there are two macronuclei and one micronucleus in the doublet and they divide amitotically and mitotically,respectively.Finally,we speculate that this special differentiation may be an adaptive form to adverse environments.展开更多
基金supported by the Natural Science Foundation of China(project number:32170533,31772477).
文摘Ciliates are important unicellular organisms in the studies of biomolecules,genetics,and evolution.Euplotids are a highly diversified and widely distributed group.The morphology of two euplotids,Euplotes dominicanus and E.parkei,isolated from the Yangtze River Estuary,China,were investigated based on live observation,protargol-,and Chatton-Lwoff staining methods.The Chinese population of E.dominicanus resembles the original abyssal population except for having two caudal cirri and seven dorsolateral kineties.The Chinese population of E.parkei corresponds well with the original description in size,having eight frontoventral cirri,two marginal cirri,and a double-eurystomus dorsal silverline system.The diagnoses were improved by incorporating newly obtained data,detailed illustrations,and photomicrographs were supplemented.Euplotes parkei sensu needs to be reinvestigated.Phylogenetic analyses based on SSU rRNA gene sequence data confirmed the branching position of the two taxa within the genus Euplotes.The geographical distribution of the genus Euplotes in China was also briefly reviewed,and further exploration is needed in the brackish habitat,particularly focusing on the estuary zone.
基金supported by the National Natural Science Foundation of China(32030015,31922013 and 31961123002)the Natural Science Foundation of Shandong Province(ZR2020JQ13)+1 种基金the Fundamental Research Funds for the Central Universities(202141004)the Researchers Supporting Project(RSP-2022R7)of the King Saud University,Saudi Arabia.
文摘Ciliated protists are one of the most diverse and highly differentiated group among unicellular organisms.Doublets occur in ciliates when two cells fuse into a single individual.Doublets contain two major cellular components(either cell in a doublet)and have traditionally been considered as developmental anomalies.Nevertheless,doublets can divide or even conjugate effectively,which may represent dispersal forms of the life stages.In addition,morphogenesis,as an important process in the life cycle,will provide important insights into the complex differentiation mechanism and various physiological phenomena.However,morphogenetic studies focusing on doublets of ciliates are very limited,which has become an obstacle to understand their complete life history.Here we isolated a doublet strain from the marine species Euplotes vannus(Müller,1786)Diesing,1850 and investigated its morphogenetic events during asexual reproduction.Our results indicate that:(1)the opisthe’s oral primordium develops de novo beneath the cortex;(2)the frontoventral and transverse cirral anlagen,cirrus I/1,and marginal anlagen in both dividers develop de novo separately;(3)the dorsal kinety anlagen,the three rightmost ones of which produce three caudal cirri for the proter,occur within the parental structures in the mid-body region;(4)the opisthe acquires two caudal cirri,one from the end of each two rightmost kineties;and(5)there are two macronuclei and one micronucleus in the doublet and they divide amitotically and mitotically,respectively.Finally,we speculate that this special differentiation may be an adaptive form to adverse environments.
