Abstract Ulva linza is one of the species that causes green tides in the Yellow Sea,China.Due to the diffi culties in chromosomal preparation,the large numbers of chromosomes,and their relatively small sizes,there hav...Abstract Ulva linza is one of the species that causes green tides in the Yellow Sea,China.Due to the diffi culties in chromosomal preparation,the large numbers of chromosomes,and their relatively small sizes,there have been no reported studies on Ulva macroalgae chromosomes.The karyotypes and chromosomes in U.linza were observed after a series of treatments.The chromosomes were pretreated with 0.1%colchicine for 12 h and then mixed with enzymes.The samples were dropped from 30 cm height onto glass slides,which spread out the surface coat.These pretreatments were the optimal chromosomes preparation treatments.The prepared chromosomes were stained with 4',6-diamidino-2-phenylindole(DAPI),which is a fl uorescent probe sensitive and specifi c to DNA.The chromosome number in the haploid male and female gametophytes was n=9,and was 2 n=18 in the diploid sporophytes.The female gametophyte chromosomes were between 0.804 and 2.292μm in size,the male gametophyte chromosomes were between 0.917 and 2.916μm,and the sporophyte chromosomes were between 0.912 and 2.167μm.The relative sizes of the chromosomes were used to analyze the karyotypes of the female and male gametophyte chromosomes.The results provide a solid foundation for the basic technique that can be used to localize molecular markers of Ulva chromosomes.展开更多
A superoxide dismutase was purified from Enteromorpha linza using a simple and safe procedure, which comprised phosphate buffer extraction, ammonium sulphate precipitation, ion exchange chromatography on Q-sepharose c...A superoxide dismutase was purified from Enteromorpha linza using a simple and safe procedure, which comprised phosphate buffer extraction, ammonium sulphate precipitation, ion exchange chromatography on Q-sepharose column, and gel filtration chromatography on Superdex 200 10/300GL. The E. linza superoxide dismutase （E/SOD） was purified 103.6-fold, and a yield of 19.1% and a specific activity of 1 750 U/rag protein were obtained. The SDS-PAGE exhibited E/SOD a single band near 23 kDa and the gel filtration study showed E/SOD＇s molecular weight is near 46 kDa in nondenatured condition, indicating it＇s a homodimeric protein. E/SOD is an iron-cofactored superoxide dismutase （Fe-SOD） because it was inhibited by hydrogen peroxide, insensitive to potassium cyanide. The optimal temperature for its maximal enzyme activity was 35℃, and it still had 29.8% relative activity at 0℃, then E/SOD can be classified as a cold-adapted enzyme. E/SOD was stable when temperature was below 40℃ or the pH was within the range of 5 10. The first 11 N-terminal amino acids orE/SOD were ALELKAPPYEL, comparison of its N-terminal sequence with other Fe-SOD N-terminal sequences at the same position suggests it is possibly a chloroplastic Fe-SOD.展开更多
Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulan...Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time （APTT）, thrombin time （TT） and prothrombin time （PT） using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester （19.0%） and uronic acid （14.9%）. The MP mainly consisted of （1→4）-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of （1→3, 4）-linked rhamnose, （1→2,4）-linked rhamnose, （1→4）-linked glucuronic acid and （1→4）-linked xylose residues. The SP contained abundant （1→4）-linked rhamnose with minor amounts of （1→3）-linked rhanmose, （1→3, 4）-linked rhamnose, （1→2, 4）-linked rhanmose, （1→4）4inked glucuronic acid, （1→4）-linked xylose, and （1→3）-linked galactose residues. The sulfate groups were mainly located at C-3 of （1→4）-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.展开更多
The green seaweeds Ulva linza and U.prolifera are closely related species.They usually co-occur widely and have important ecological significance as primary producers thriving in the intertidal zone.In the Yellow Sea,...The green seaweeds Ulva linza and U.prolifera are closely related species.They usually co-occur widely and have important ecological significance as primary producers thriving in the intertidal zone.In the Yellow Sea,a genetically unique floating ecotype of U.prolifera even bloomed to cause serious green tides.However,there is still a lack of appropriate molecular markers to distinguish these two species,partially due to limited evaluations on the intraspecific variations in U.prolifera among dif ferent ecotypes.Since organelle genomes could provide rich genetic resources for phylogenetic analysis and development of genetic markers,in this study,the chloroplast genome from one attached population of U.prolifera was completely sequenced,and comparative genomic analyses were performed with other existing chloroplast genomes from U.linza and the floating ecotype of U.prolifera.The results showed that in spite of the high level of collinearity among three genomes,there were plenty of genetic variations especially within the non-coding regions,including introns and gene spacer regions.A strategy was proposed that only those signals of variation,which were identical between two ecotypes of U.prolifera but divergent between U.linza and U.prolifera,were selected to develop the interspecific markers for U.linza and U.prolifera.Two candidate markers,psa B and pet B,were shown to be able to distinguish these two closely related species and were applicable to more attached populations of U.prolifera from a wide range of geographical sources.In addition to the interspecific marker,this study would also provide resources for the development of intraspecific markers for U.prolifera.These markers might contribute to the surveys for Ulva species composition and green tide monitoring especially in the Yellow Sea region.展开更多
基金Supported by the National Key R&D Program of China(No.2018YFD0901500)the Shanghai Sailing Program(No.17YF1407900),the National Natural Science Foundation of China(No.41576163)the Ocean Public Welfare Scientifi c Research Project,China(No.201205010)。
文摘Abstract Ulva linza is one of the species that causes green tides in the Yellow Sea,China.Due to the diffi culties in chromosomal preparation,the large numbers of chromosomes,and their relatively small sizes,there have been no reported studies on Ulva macroalgae chromosomes.The karyotypes and chromosomes in U.linza were observed after a series of treatments.The chromosomes were pretreated with 0.1%colchicine for 12 h and then mixed with enzymes.The samples were dropped from 30 cm height onto glass slides,which spread out the surface coat.These pretreatments were the optimal chromosomes preparation treatments.The prepared chromosomes were stained with 4',6-diamidino-2-phenylindole(DAPI),which is a fl uorescent probe sensitive and specifi c to DNA.The chromosome number in the haploid male and female gametophytes was n=9,and was 2 n=18 in the diploid sporophytes.The female gametophyte chromosomes were between 0.804 and 2.292μm in size,the male gametophyte chromosomes were between 0.917 and 2.916μm,and the sporophyte chromosomes were between 0.912 and 2.167μm.The relative sizes of the chromosomes were used to analyze the karyotypes of the female and male gametophyte chromosomes.The results provide a solid foundation for the basic technique that can be used to localize molecular markers of Ulva chromosomes.
基金Supported by the National Key Technology R&D Program of China(No.2012BAC07B03)
文摘A superoxide dismutase was purified from Enteromorpha linza using a simple and safe procedure, which comprised phosphate buffer extraction, ammonium sulphate precipitation, ion exchange chromatography on Q-sepharose column, and gel filtration chromatography on Superdex 200 10/300GL. The E. linza superoxide dismutase （E/SOD） was purified 103.6-fold, and a yield of 19.1% and a specific activity of 1 750 U/rag protein were obtained. The SDS-PAGE exhibited E/SOD a single band near 23 kDa and the gel filtration study showed E/SOD＇s molecular weight is near 46 kDa in nondenatured condition, indicating it＇s a homodimeric protein. E/SOD is an iron-cofactored superoxide dismutase （Fe-SOD） because it was inhibited by hydrogen peroxide, insensitive to potassium cyanide. The optimal temperature for its maximal enzyme activity was 35℃, and it still had 29.8% relative activity at 0℃, then E/SOD can be classified as a cold-adapted enzyme. E/SOD was stable when temperature was below 40℃ or the pH was within the range of 5 10. The first 11 N-terminal amino acids orE/SOD were ALELKAPPYEL, comparison of its N-terminal sequence with other Fe-SOD N-terminal sequences at the same position suggests it is possibly a chloroplastic Fe-SOD.
基金supported by the National Natural Science Foundation of China (No.41076086)the National Oceanographic Center of Qingdao, China and the Science and Technology Development Program of Shandong Province, China (No.2010GHY10509)
文摘Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time （APTT）, thrombin time （TT） and prothrombin time （PT） using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester （19.0%） and uronic acid （14.9%）. The MP mainly consisted of （1→4）-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of （1→3, 4）-linked rhamnose, （1→2,4）-linked rhamnose, （1→4）-linked glucuronic acid and （1→4）-linked xylose residues. The SP contained abundant （1→4）-linked rhamnose with minor amounts of （1→3）-linked rhanmose, （1→3, 4）-linked rhamnose, （1→2, 4）-linked rhanmose, （1→4）4inked glucuronic acid, （1→4）-linked xylose, and （1→3）-linked galactose residues. The sulfate groups were mainly located at C-3 of （1→4）-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.
基金Supported by the Science&Technology Basic Resources Investigation Program of China(No.2018FY100205)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050302)+2 种基金the National Key R&D Program of China(No.2018YFD0901500)the National Natural Science Foundation of China(No.41776153)the Key R&D Program of Shandong Province(No.2019GSF107012)。
文摘The green seaweeds Ulva linza and U.prolifera are closely related species.They usually co-occur widely and have important ecological significance as primary producers thriving in the intertidal zone.In the Yellow Sea,a genetically unique floating ecotype of U.prolifera even bloomed to cause serious green tides.However,there is still a lack of appropriate molecular markers to distinguish these two species,partially due to limited evaluations on the intraspecific variations in U.prolifera among dif ferent ecotypes.Since organelle genomes could provide rich genetic resources for phylogenetic analysis and development of genetic markers,in this study,the chloroplast genome from one attached population of U.prolifera was completely sequenced,and comparative genomic analyses were performed with other existing chloroplast genomes from U.linza and the floating ecotype of U.prolifera.The results showed that in spite of the high level of collinearity among three genomes,there were plenty of genetic variations especially within the non-coding regions,including introns and gene spacer regions.A strategy was proposed that only those signals of variation,which were identical between two ecotypes of U.prolifera but divergent between U.linza and U.prolifera,were selected to develop the interspecific markers for U.linza and U.prolifera.Two candidate markers,psa B and pet B,were shown to be able to distinguish these two closely related species and were applicable to more attached populations of U.prolifera from a wide range of geographical sources.In addition to the interspecific marker,this study would also provide resources for the development of intraspecific markers for U.prolifera.These markers might contribute to the surveys for Ulva species composition and green tide monitoring especially in the Yellow Sea region.
