Objective:The effectiveness of the slimy substance in snail to regenerate and repair damaged areas on it body/shell lead to this investigation.Methods:The anti-ulcer’property of snail slime extracted from phylur moll...Objective:The effectiveness of the slimy substance in snail to regenerate and repair damaged areas on it body/shell lead to this investigation.Methods:The anti-ulcer’property of snail slime extracted from phylur mollusca(tropical snail) from the giant African snail Archachatina marginata(Fam.Arionidae) was investi gated using histamine,stress and indomethacin-induced ulcers.The solubility profile of extract was investiga ted in different solvents and at different temperatures.Chemical analysis was carried out to determine the type of constituents present in the slim,while acute toxicity test was carried out to evaluate its profile of toxicity The effect of the snail slim on gastrointestinal motility was investigated in mice,while the guinea pig ileum wa used to study the effect of the extract on contraction produced by acetylcholine and histamine.The snail slim contained copious quantity of protein,with varying amounts of simple sugars,carbohydrates and fats.Th slime was not soluble in most common solvents and increases in temperature,did not appear to increase its sol ubility.Results:The result further indicated that although the snail slime exhibited significant(P【0.05) an ti -ulcer induced by stress and histamine,it was most potent against ulcer induced by indomethacin.The snai slime potently inhibited gastrointestinal movement in mice in a dose-dependent manner;however,it was not a ble to inhibit contraction induced by acetylcholine and histamine in guinea pig ileum.Conclusion:The snai mucin possesses potent antiulcer properties without any toxic effect.The mechanism responsible for the anti-ul cer property may not be postulated with certainty but cytoprotective and anti-spasmodic activities are most likel to be involved.展开更多
The origins and radiations of metazoans, bilat- erians, deuterostomes and vertebrates have been recognized as the four most important milestone events in animal his- tory and, conversely four of the toughest and puzzl...The origins and radiations of metazoans, bilat- erians, deuterostomes and vertebrates have been recognized as the four most important milestone events in animal his- tory and, conversely four of the toughest and puzzling ques- tions in evolutionary biology. Among them, the first two oc- curred in the deep time of the Precambrian and have left little information in the fossil records. Fortunately, intensive investigation into the Early Cambrian Chengjiang faunas in the past two decades have revealed numerous significant data on the main episode of the Cambrian Explosion, par- ticularly information on the various earliest-known deu- terostomes, leading to a much better understanding of the last two events. The “first fish” Haikouichthys and Myllo- kunmingia have been proved the oldest-known vertebrates, and to be among the most primitive ones, representing a key transitional group from acraniates to craniates. Indeed, “Pa- leontological work of Shu and collaborators is revising our understanding of the early evolution of chordates”. Moreover, the discovery of the Phylum Vetulicolia may also throw new light on the origin of deuterostomes. This extinct group with simple gill slits might represent one of the roots in the deu- terostome lineage, as the evidence of molecular biology and developmental biology has predicted. Here the first discovery of tiny vetulicolians from the Chengjiang Lagerst?tte is re- ported. The evolutionary trend from the giant to the small might represent a special adaptation in early animal history. Since all vetulicolians share similar characters in their ante- rior section (pharynx), and on the basis of differences in their posterior section, a new classification system is proposed, with a new class, the Heteromorphida erected. As both the “root” group vetulicolians and the “top” group vertebrates in the early deuterostome lineage, as well as those members in between, such as vetulocystids, yunnanozoans, cephalo- chordates and urochordates, have been recovered, a rela- tively complete early deuterostome phylogeny, which is compatible with phylogenies of extant deuterostomes, is nearly mature.展开更多
Bioevolution is still a main puzzle and attracts many scientists to research on it. Here I present that organisms have two impor- tant properties, definite structure and self-reproduction. Based on the number and conn...Bioevolution is still a main puzzle and attracts many scientists to research on it. Here I present that organisms have two impor- tant properties, definite structure and self-reproduction. Based on the number and connection of the structural units, organisms can be di- vided into three groups, unicellular, particellular and polycellular organisms. It can be called polycellular evolution that organisms evolve from unicellular, particellular to polycellular. Also it can be called diploid evolution that organisms evolve from haplobes to diplobes, two groups based on the reproductive differences. Some concepts like spore, zygote and embryos are redefined in the paper. Moreover, I present that embryos are the most important boundary of bioevolution and organisms can be divided into two evolutionary phases, the lower and the higher. The lower organisms, Kingdom Microbia (kingd. nov.), are inembryonate, which include Acytophyla (phyl. nov.), bacteria, protozoa, fungi and inembryonate algae. The higher organisms are embryonate and have two branches, Kingdom Plantae and Kingdom Animalia. Plantae are sessile and, autotrophic or sporogenic, which include higher plants and Nudembryophyta (phyl. nov.). Animalia are heterotrophic and, motile or gametogenic, which include all multicellular animals. The new system, which reflects the two important phases of bioevolu- tion and two branches of higher organisms, can really correct the problem of different kingdoms in different researches or by different re- searchers.展开更多
内陆湿地与水体(如湖泊、河流、水库等)是温室气体甲烷的重要排放源。微生物介导的甲烷厌氧氧化(anaerobic oxidation of methane,AOM)反应在控制内陆湿地与水体甲烷排放中起着不可忽视的作用,对缓解全球温室效应具有重要意义。内陆湿...内陆湿地与水体(如湖泊、河流、水库等)是温室气体甲烷的重要排放源。微生物介导的甲烷厌氧氧化(anaerobic oxidation of methane,AOM)反应在控制内陆湿地与水体甲烷排放中起着不可忽视的作用,对缓解全球温室效应具有重要意义。内陆湿地与水体易形成缺氧环境,且电子受体的种类和数量繁多,是发生AOM反应的理想生境。近年来,不断有研究表明,内陆湿地与水体中存在多种电子受体(NO^(-)_(2)、NO^(-)_(3)、SO^(2-)_(4)、Fe(Ⅲ)等)驱动的AOM途径。NC10门细菌和甲烷厌氧氧化古菌(anaerobic methanotrophic archaea,ANME)的一新分支ANME^(-)_(2)d主导了湿地和水体环境中的AOM反应,其中ANME^(-)_(2)d具有根据环境条件选择不同电子受体的潜力。研究系统综述了内陆湿地与水体中不同电子受体驱动的AOM途径及其参与的主要功能微生物类群;分析了AOM反应在控制温室气体甲烷排放中的作用及其环境影响因素;总结了相关功能微生物的分子生物学检测方法及甲烷厌氧氧化活性测定的同位素示踪技术。最后,对未来相关研究方向进行了展望。展开更多
文摘Objective:The effectiveness of the slimy substance in snail to regenerate and repair damaged areas on it body/shell lead to this investigation.Methods:The anti-ulcer’property of snail slime extracted from phylur mollusca(tropical snail) from the giant African snail Archachatina marginata(Fam.Arionidae) was investi gated using histamine,stress and indomethacin-induced ulcers.The solubility profile of extract was investiga ted in different solvents and at different temperatures.Chemical analysis was carried out to determine the type of constituents present in the slim,while acute toxicity test was carried out to evaluate its profile of toxicity The effect of the snail slim on gastrointestinal motility was investigated in mice,while the guinea pig ileum wa used to study the effect of the extract on contraction produced by acetylcholine and histamine.The snail slim contained copious quantity of protein,with varying amounts of simple sugars,carbohydrates and fats.Th slime was not soluble in most common solvents and increases in temperature,did not appear to increase its sol ubility.Results:The result further indicated that although the snail slime exhibited significant(P【0.05) an ti -ulcer induced by stress and histamine,it was most potent against ulcer induced by indomethacin.The snai slime potently inhibited gastrointestinal movement in mice in a dose-dependent manner;however,it was not a ble to inhibit contraction induced by acetylcholine and histamine in guinea pig ileum.Conclusion:The snai mucin possesses potent antiulcer properties without any toxic effect.The mechanism responsible for the anti-ul cer property may not be postulated with certainty but cytoprotective and anti-spasmodic activities are most likel to be involved.
基金supported by the National Natural Science Foundation of China(Grant Nos.30270207,40332016)Ministry of Science and Technology of China(Grant No.G000077700)Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT).
文摘The origins and radiations of metazoans, bilat- erians, deuterostomes and vertebrates have been recognized as the four most important milestone events in animal his- tory and, conversely four of the toughest and puzzling ques- tions in evolutionary biology. Among them, the first two oc- curred in the deep time of the Precambrian and have left little information in the fossil records. Fortunately, intensive investigation into the Early Cambrian Chengjiang faunas in the past two decades have revealed numerous significant data on the main episode of the Cambrian Explosion, par- ticularly information on the various earliest-known deu- terostomes, leading to a much better understanding of the last two events. The “first fish” Haikouichthys and Myllo- kunmingia have been proved the oldest-known vertebrates, and to be among the most primitive ones, representing a key transitional group from acraniates to craniates. Indeed, “Pa- leontological work of Shu and collaborators is revising our understanding of the early evolution of chordates”. Moreover, the discovery of the Phylum Vetulicolia may also throw new light on the origin of deuterostomes. This extinct group with simple gill slits might represent one of the roots in the deu- terostome lineage, as the evidence of molecular biology and developmental biology has predicted. Here the first discovery of tiny vetulicolians from the Chengjiang Lagerst?tte is re- ported. The evolutionary trend from the giant to the small might represent a special adaptation in early animal history. Since all vetulicolians share similar characters in their ante- rior section (pharynx), and on the basis of differences in their posterior section, a new classification system is proposed, with a new class, the Heteromorphida erected. As both the “root” group vetulicolians and the “top” group vertebrates in the early deuterostome lineage, as well as those members in between, such as vetulocystids, yunnanozoans, cephalo- chordates and urochordates, have been recovered, a rela- tively complete early deuterostome phylogeny, which is compatible with phylogenies of extant deuterostomes, is nearly mature.
文摘Bioevolution is still a main puzzle and attracts many scientists to research on it. Here I present that organisms have two impor- tant properties, definite structure and self-reproduction. Based on the number and connection of the structural units, organisms can be di- vided into three groups, unicellular, particellular and polycellular organisms. It can be called polycellular evolution that organisms evolve from unicellular, particellular to polycellular. Also it can be called diploid evolution that organisms evolve from haplobes to diplobes, two groups based on the reproductive differences. Some concepts like spore, zygote and embryos are redefined in the paper. Moreover, I present that embryos are the most important boundary of bioevolution and organisms can be divided into two evolutionary phases, the lower and the higher. The lower organisms, Kingdom Microbia (kingd. nov.), are inembryonate, which include Acytophyla (phyl. nov.), bacteria, protozoa, fungi and inembryonate algae. The higher organisms are embryonate and have two branches, Kingdom Plantae and Kingdom Animalia. Plantae are sessile and, autotrophic or sporogenic, which include higher plants and Nudembryophyta (phyl. nov.). Animalia are heterotrophic and, motile or gametogenic, which include all multicellular animals. The new system, which reflects the two important phases of bioevolu- tion and two branches of higher organisms, can really correct the problem of different kingdoms in different researches or by different re- searchers.
