Objective:To investigate the seasonal fluctuations of the proximate composition of the ascidians muscle.Methods:The moisture content was estimated by drying 1 g of fresh tissue at a constant temperature at 105(?)for 2...Objective:To investigate the seasonal fluctuations of the proximate composition of the ascidians muscle.Methods:The moisture content was estimated by drying 1 g of fresh tissue at a constant temperature at 105(?)for 24 h.The loss of weight was taken as moisture content.The total protein was estimated using the Biuret method.The total carbohydrate in dried sample was estimated spectrophotometrically following the phenol-sulphuric acid method.The lipid in the dried sample tissue was gravimetrically estimated following the chloroform-methanol mixture method.Ash content was determined gravimetrically by incinerating 1 g dried sample in muffle furnace at about 550℃for 6 h and results are expressed in percentage.Results:It was found very difficult to compare the monthly variations,as all the ten species,exhibited wide fluctuations in their proximate compositions.For the sake of convenience,average seasonal values were calculated by summing the monthly values.Conclusions:The proximate composition of the 10 commonly available ascidians showed high nutritive value and hence these groups especially solitary ascidians can be recommended for human consumption in terms of pickles,soup,curry and others after ensuring the safety of consumers.展开更多
The ascidian Styela clava is an ecologically important species that is distributed along coastal regions worldwide.It has a long history as a model animal for evolutionary and developmental biology research owing to i...The ascidian Styela clava is an ecologically important species that is distributed along coastal regions worldwide.It has a long history as a model animal for evolutionary and developmental biology research owing to its phylogenetic position between vertebrates and invertebrates,and its classical mosaic expression patterns.However,the standard developmental atlas and protocols and tools for molecular manipulation of this organism are inadequate.In this study,we established a standard developmental table and provided a web-based digital image resource for S.clava embryogenesis at each developmental stage from fertilized eggs to hatching larvae by utilizing confocal laser microscopy and 3D reconstruction images.It takes around 10 h for fertilized eggs to develop into swimming larvae and 20–30 min to complete the tail regression processes at the metamorphic stage.We observed that the notochord cells in S.clava embryos did not produce an extracellular lumen like Ciona robusta,but showed polarized elongation behaviors,providing us an ideal comparative model to study tissue morphogenesis.In addition,we established a chemical-washing procedure to remove the chorion easily from the fertilized eggs.Based on the dechorionation technique,we further realized transgenic manipulation by electroporation and successfully applied tissue-specific fluorescent labeling in S.clava embryos.Our work provides a standard imaging atlas and powerful genetic tools for investigating embryogenesis and evolution using S.clava as a model organism.展开更多
A new cyclic peptide, prepatellamide A (1), along with three known cyclic peptides (2)— (4), was isolated from the ascidianLissoclinum patella. The structure of prepatellamide A was determined from one- and two-dimen...A new cyclic peptide, prepatellamide A (1), along with three known cyclic peptides (2)— (4), was isolated from the ascidianLissoclinum patella. The structure of prepatellamide A was determined from one- and two-dimensional1H and13C NMR spectra. The known cyclic peptides were identified as patellamides A (2), B (3) and C (4).展开更多
It has long been known that abundant symbiotic bacteria exist in the tunic and gut of marine ascidians,and that these play crucial roles in host development,physiological metabolism,and environmental adaptation.Howeve...It has long been known that abundant symbiotic bacteria exist in the tunic and gut of marine ascidians,and that these play crucial roles in host development,physiological metabolism,and environmental adaptation.However,the identity,roles and functions of these symbiotic bacteria are known for only a few strains.In this study,we isolated and cultivated 263 strains of microorganisms from the intestine of the marine ascidian Halocynthia roretzi through a combination of aerobic and anaerobic culture approaches.Most cultivated species,both aerobic and anaerobic,from ascidian stool samples belonged to the genus Bacillus based on 16S rDNA sequencing identification and phylogenetic assays.The distribution of cultured bacteria varied with seasonal changes in environmental conditions.To explore the functions of cultured bacteria,we screened out a strain of Serratia sp.whose extracts showed high antibacterial activity against aquatic pathogens.These findings revealed the potential roles of gut microorganisms in ascidian defense and environmental adaptation,thus providing insights into the interaction and co-evolution between gut bacteria and their hosts.展开更多
基金suppotted by Ministry of Earth SciencesGovernment of India(Number:G4/5656/08)
文摘Objective:To investigate the seasonal fluctuations of the proximate composition of the ascidians muscle.Methods:The moisture content was estimated by drying 1 g of fresh tissue at a constant temperature at 105(?)for 24 h.The loss of weight was taken as moisture content.The total protein was estimated using the Biuret method.The total carbohydrate in dried sample was estimated spectrophotometrically following the phenol-sulphuric acid method.The lipid in the dried sample tissue was gravimetrically estimated following the chloroform-methanol mixture method.Ash content was determined gravimetrically by incinerating 1 g dried sample in muffle furnace at about 550℃for 6 h and results are expressed in percentage.Results:It was found very difficult to compare the monthly variations,as all the ten species,exhibited wide fluctuations in their proximate compositions.For the sake of convenience,average seasonal values were calculated by summing the monthly values.Conclusions:The proximate composition of the 10 commonly available ascidians showed high nutritive value and hence these groups especially solitary ascidians can be recommended for human consumption in terms of pickles,soup,curry and others after ensuring the safety of consumers.
基金supported by the National Key Research and Development Program of China(2022YFC2601304,2022YFC2601302)the Science&Technology Innovation Project of Laoshan Laboratory(LSKJ202203002)+2 种基金the Taishan Scholar Program of Shandong Province,China(to BD)Database Construction was supported by the Research Institute of Marine Invertebrates(IKU2021-02)the Keio University Doctorate Student Grant-in-Aid Program from Ushioda Memorial Fund and JSPS KAKENHI Grant Number JP 22J22628,and Keio Gijuku Education with a Research-Adjusted Budget to TTS.
文摘The ascidian Styela clava is an ecologically important species that is distributed along coastal regions worldwide.It has a long history as a model animal for evolutionary and developmental biology research owing to its phylogenetic position between vertebrates and invertebrates,and its classical mosaic expression patterns.However,the standard developmental atlas and protocols and tools for molecular manipulation of this organism are inadequate.In this study,we established a standard developmental table and provided a web-based digital image resource for S.clava embryogenesis at each developmental stage from fertilized eggs to hatching larvae by utilizing confocal laser microscopy and 3D reconstruction images.It takes around 10 h for fertilized eggs to develop into swimming larvae and 20–30 min to complete the tail regression processes at the metamorphic stage.We observed that the notochord cells in S.clava embryos did not produce an extracellular lumen like Ciona robusta,but showed polarized elongation behaviors,providing us an ideal comparative model to study tissue morphogenesis.In addition,we established a chemical-washing procedure to remove the chorion easily from the fertilized eggs.Based on the dechorionation technique,we further realized transgenic manipulation by electroporation and successfully applied tissue-specific fluorescent labeling in S.clava embryos.Our work provides a standard imaging atlas and powerful genetic tools for investigating embryogenesis and evolution using S.clava as a model organism.
文摘A new cyclic peptide, prepatellamide A (1), along with three known cyclic peptides (2)— (4), was isolated from the ascidianLissoclinum patella. The structure of prepatellamide A was determined from one- and two-dimensional1H and13C NMR spectra. The known cyclic peptides were identified as patellamides A (2), B (3) and C (4).
基金supported by the National Key Research and Development Program of China(Grant no.2018YFD0900705)the National Natural Science Foundation of China(Grant no.31970487).
文摘It has long been known that abundant symbiotic bacteria exist in the tunic and gut of marine ascidians,and that these play crucial roles in host development,physiological metabolism,and environmental adaptation.However,the identity,roles and functions of these symbiotic bacteria are known for only a few strains.In this study,we isolated and cultivated 263 strains of microorganisms from the intestine of the marine ascidian Halocynthia roretzi through a combination of aerobic and anaerobic culture approaches.Most cultivated species,both aerobic and anaerobic,from ascidian stool samples belonged to the genus Bacillus based on 16S rDNA sequencing identification and phylogenetic assays.The distribution of cultured bacteria varied with seasonal changes in environmental conditions.To explore the functions of cultured bacteria,we screened out a strain of Serratia sp.whose extracts showed high antibacterial activity against aquatic pathogens.These findings revealed the potential roles of gut microorganisms in ascidian defense and environmental adaptation,thus providing insights into the interaction and co-evolution between gut bacteria and their hosts.
