Morphogenesis of a population of the marine euplotid ciliate, Uronychia binucleata, which was found in Yellow Sea coastal waters next to a sewage outfall at a beach near Zhanqiao Pier, Qingdao, China, was investigated...Morphogenesis of a population of the marine euplotid ciliate, Uronychia binucleata, which was found in Yellow Sea coastal waters next to a sewage outfall at a beach near Zhanqiao Pier, Qingdao, China, was investigated using protargol staining. The main pattern of morphogenesis is typical for the genus and can be summarized as follows: 1) the oral primordium in both proter and opisthe develops de novo in a subcortical pouch. In each daughter cell, the developing adoral zone of membranelles divides into two parts. The new membranelles formed in the proter's oral primordium will replace the leftmost five parental ones; six parental membranelles are retained by the proter; 2) the undulating membranes anlage is formed and develops independently from the oral primordium within the same subcortical pouch; 3) five primary front oventral-transverse cirral anlagen appear de novo on the cell surface; 4) the marginal cirral anlagen are formed de novo; 5) the leftmost frontal cirrus develops de novo on the cell surface; 6) two caudal cirri are formed at the posterior end of the rightmost anlage while the second primordium from the right gives rise to the third caudal cirrus. In contrast to its congeners, the anlage of the leftmost frontal cirrus is formed to the right of the undulating membranes anlage and before the formation of the latter.展开更多
The ultrastructure of ciliates carries important cytological,taxonomical,and evolutionary signals for these single-celled eukaryotic organisms.However,little ultrastructural data have been accumulated for most ciliate...The ultrastructure of ciliates carries important cytological,taxonomical,and evolutionary signals for these single-celled eukaryotic organisms.However,little ultrastructural data have been accumulated for most ciliate groups with systematic problems.In the present work,a well-known marine uronychiid,Diophrys appendiculata,was investigated using electron microscopy and a comparison with,and a discussion considering,phylogenetic analyses were made.The new findings primarily show that:(i)this species lacks the typical alveolar plate,bears cortical ampule-like extrusomes,and has microtubular triads in the dorsal pellicle,and thus exhibits some ultrastructural features in common with most of its previously studied congeners;(ii)each adoral membranelle before the level of frontal cirrus II/2 contains three rows of kinetosomes and each membranelle after the level of frontal cirrus II/2 contains four rows,which might be related with morphogenesis and could be considered as a distinctive character of Diophrys;(iii)some structural details of the buccal field,such as the extra-pellicular fibrils,pellicle,pharyngeal disks and microtubular sheet,were documented.In addition,based on the ultrastructural comparison of representatives,we discuss the differentiation between the subfamilies Diophryinae and Uronychiinae.A hypothetical systematic relationship of members in the order Euplotida based on a wide range of data is also provided.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 31872190, 31702009)the Key Laboratory of Mariculture (KLM), Ministry of Education, Ocean University of China (OUC)the Innovation Team of Team of Higher Learning Insritutions of Tianjin (No. TD13-5089)
文摘Morphogenesis of a population of the marine euplotid ciliate, Uronychia binucleata, which was found in Yellow Sea coastal waters next to a sewage outfall at a beach near Zhanqiao Pier, Qingdao, China, was investigated using protargol staining. The main pattern of morphogenesis is typical for the genus and can be summarized as follows: 1) the oral primordium in both proter and opisthe develops de novo in a subcortical pouch. In each daughter cell, the developing adoral zone of membranelles divides into two parts. The new membranelles formed in the proter's oral primordium will replace the leftmost five parental ones; six parental membranelles are retained by the proter; 2) the undulating membranes anlage is formed and develops independently from the oral primordium within the same subcortical pouch; 3) five primary front oventral-transverse cirral anlagen appear de novo on the cell surface; 4) the marginal cirral anlagen are formed de novo; 5) the leftmost frontal cirrus develops de novo on the cell surface; 6) two caudal cirri are formed at the posterior end of the rightmost anlage while the second primordium from the right gives rise to the third caudal cirrus. In contrast to its congeners, the anlage of the leftmost frontal cirrus is formed to the right of the undulating membranes anlage and before the formation of the latter.
基金supported by the National Natural Science Foundation of China(32170446,32030015,31961123002)the National Natural Science Foundation of Shanghai(21ZR1419000).
文摘The ultrastructure of ciliates carries important cytological,taxonomical,and evolutionary signals for these single-celled eukaryotic organisms.However,little ultrastructural data have been accumulated for most ciliate groups with systematic problems.In the present work,a well-known marine uronychiid,Diophrys appendiculata,was investigated using electron microscopy and a comparison with,and a discussion considering,phylogenetic analyses were made.The new findings primarily show that:(i)this species lacks the typical alveolar plate,bears cortical ampule-like extrusomes,and has microtubular triads in the dorsal pellicle,and thus exhibits some ultrastructural features in common with most of its previously studied congeners;(ii)each adoral membranelle before the level of frontal cirrus II/2 contains three rows of kinetosomes and each membranelle after the level of frontal cirrus II/2 contains four rows,which might be related with morphogenesis and could be considered as a distinctive character of Diophrys;(iii)some structural details of the buccal field,such as the extra-pellicular fibrils,pellicle,pharyngeal disks and microtubular sheet,were documented.In addition,based on the ultrastructural comparison of representatives,we discuss the differentiation between the subfamilies Diophryinae and Uronychiinae.A hypothetical systematic relationship of members in the order Euplotida based on a wide range of data is also provided.
