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amphioxus

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amphioxus n.【動物；動物學】蛞蝓魚，文昌魚。

n. 【動物；動物學】蛞蝓魚，文昌魚。 “amphioxus-plan of circulat－ory system“ 中文翻譯：   文昌魚型循環系“amphioxiformes“ 中文翻譯：   文昌魚目“amphipacific species“ 中文翻譯：   太平洋兩岸屬“amphioxea“ 中文翻譯：   兩頭尖骨針“amphipath“ 中文翻譯：   兩歧性分子; 親水脂分子“amphiox“ 中文翻譯：   兩頭尖針“amphipathic“ 中文翻譯：   兩親的; 兩性分子團的; 親水疏水兩重性的; 中極兩性的“amphiorientation“ 中文翻譯：   雙定向“amphipathic adsorption“ 中文翻譯：   兩親吸附作用“amphion“ 中文翻譯：   安菲翁; 安費恩; 兩性離子

The reason for this is unknown at the present . possibly , cg - rich and at - rich regions in amphioxus dna are not as “ rich “ as those in the vertebrate dna , that is , amphioxus dna ha 雖然nogusa ( 1957 )認為b . belcheri存在xy型的性染色體，至于青島文昌魚的性染色體是xy型或zw型尚待深入研究。

amphipod

However , amphioxus ubf80 also showed some unique characters such as its amino acid residues at sites 39 , 54 , 63 and 74 in the cep . it appears that amphioxus not only represents an organism tr ansitional from invertebrates to vertebrates in phylogeny but also a possible diverged form radiated from the chordate ancestor at early chordate evolution . the possibility that some mutations in ub genes have taken place in different lines early at the divergence of plants and animals is also discussed 發現文昌魚a二phi尸rxv基因是具有線粒體和過氧化物酶體信號特征( mitochondrialandperoxisomalsortingsignals )的抗氧化物酶基因;通過序列比對，我們把尸rxv歸為l一cys和2一cys之外的3一cys類，從而把尸rx基因家族的兩種分類方法統一了起來。

G - banding the gtg banding ( g - banding ) was carried out by the standard trypsin method with slight modification , which works well for protochordate because a good number of reproducible g - bands are consistently obtained from the embryonic cells of late blastulae and early gastrulae of amphioxus b . belcheri tsingtauense G帶型用稍作修改的標準的胰酶顯帶技術，進行gtg帶紋的顯示，它們能較好地顯示頭索動物青島文昌魚的晚期囊胚和早期原腸胚的中期染色體的g帶，并且重復性好。

Whole mount in situ hybridization showed that amphihmgb transcripts were present ubiquitously in the early embryos from zygote to neurula , but they decreased gradually in mesoderm and endoderm and neural tube with development , and became restricted to epidermal cells in the hatched larva . it appear s that hmgb plays a role in the mitosis and differentiation of embryonic cells . another amphioxus cdna , amphiubf80 , encoding ubiquitin / ribosomal fused protein s27a , was isolated from the gut cdna library of b . belcheri tsingtauense S004cdna序列編碼一個156個氨基酸殘基組成的蛋白質，與人的泛素蛋白ubf80具有較高的氨基酸序列同源性( 145 / 156同源) ，且該蛋白具有泛素蛋白ubf80所共有的兩個結構域，即由72個氨基酸組成的泛素介導的蛋白降解結構域和由48個氨基酸組成的核糖體蛋白s27a結構域。

The presence of complement - like activity in the humoral fluid of amphioxus was examined . the complement classical pathway ( cp ) activity is assayed by determining the amount of serum required to hemolyse a given number of sensitized sheep red blood cells ( srbc ) , whereas the complement alternative pathway ( ap ) activity measured in the same manner , but by using rabbit red blood cells ( rarbc ) instead of sensitized srbc 文昌魚體液可溶解懸浮在10mmol legta - mg - gvb緩沖液中的正常的兔血紅細胞、綿羊紅細胞、及部分哺乳動物、鳥類、兩棲類和魚類的代表動物的血紅細胞；而在gvb ~ ( 2 + )緩沖液中時對抗體包被的綿羊紅細胞卻沒有溶血活性。

In this paper , the presence of lectins in the skin mucus of amphioxus was verified by the aggutination assay and the effects of physical and chemical treatments on hemagglutination activity of amphioxus skin mucus were tested by the means of heat treatment and ph treatment 本文利用青島文昌魚體表粘液凝集反應、熱處理、 ph處理文昌魚體表粘液及糖抑制文昌魚體表粘液凝集反應等免疫學實驗方法驗證了青島文昌魚(且belcheritsingtaunese )體表粘液中的凝集素的存在并對其性質進行了研究。

Phylogenetic analysis based on the amino acids of the ubiquitin / ribosomal fused proteins of different animals well reflected the established phylogeny of the chosen organisms , and amphioxus was branched off from chordates and formed a separate cluster with an intermediate placement between invertebrates and vertebrates in the tree 通過對ubiquitin的系統進化分析，發現文昌魚ubf80除了具有脊椎動物和無脊椎動物的特征外，還具有自己的一些獨特的特征，從分子水平上支持了文昌魚是脊索動物進化過程中的一側枝的觀點。

The hemagglutinating activity of amphioxus skin mucus was decreased after heating at 60 for 30 min , and was almost lost upon heating at 100 for 30 min . the hemagglutinating activity of the skin mucus remained stable in the ph range from 6 to 10 , but it was inactivated at ph above 10 or below 6 . the hemagglutinating activity in the skin mucus is inhibited by d - galactose , which is same with the hemagglut inating activity of the humoral fluids of amphioxus 在60保溫30分鐘后，凝集素的凝集活性下降，在100保溫30分鐘后，凝集素凝集活性幾乎完全消失；在ph6 - 10的范圍內，凝集素的凝集活性穩定， ph大于10小于6的條件下，凝集素的凝集活性消失；文昌魚體表粘液中的凝集素受d -半乳糖苷的抑制。

This showed that the diploid chromosome number ( 2n ) of amphioxus b . belcheri tsingtauense was 36 . the chromosomes were extremely small , ranging from 1 . 4 to 3 . 7 um in length . the first pair of the 36 chromosomes of b . belcheri tsingtauense was subtelocentric and the other 17 pairs telocentric . neither metacentric nor submetacentric chromosomes nor satellites were observed 在36條染色體中，除第一對染色體屬亞端部著絲粒染色體( st )外，其余均為端部著絲粒染色體( t ) ，未見中部著絲粒染色體( m )和亞中部著絲粒染色體( sm )及隨體。

Amphioxus , an existing animal that belongs to the phylum chordata , subphyla cephalochordata , is always regarded as the invertebrates which is the nearest to the vertebrates . it has great sense on the research of how the vertebrates develop from invertebrates 長久以來，文昌魚一直被認為是現存的與脊椎動物親緣關系最近的無脊椎動物( stokeandholland , 1998 ; zhangetal . , 2001 ) ，在脊椎動物如何由無脊椎動物進化而來這一著名的生物學難題中占據重要的位置。

However , only three species of the cephalochordate including b . lanceolatum , b . floridae , and b . belcheri , have so far been studied for their chromosome numbers , and the karyotypic analysis and banding study of amphioxus chromosomes remains largely untouched Floridae 、 b belcheri三種文昌魚染色體數目。有關文昌魚染色體核型和帶型的研究尚未見任何報道，文昌魚染色體核型和帶型的研究將為比較基因組學和細胞遺傳學研究提供珍貴的背景資料。

It has been recognized as the most important model animal to analyze the origin and evolution of vertebrates . study on the gene structure , function and expression in amphioxus will greatly contribute to the origin and evolution of the vertebrates 利用分子生物學手段，研究文昌魚有關基因的結構、進化和表達，可為我們從分子水平上解開脊椎動物起源的奧秘；更重要的是，將進化與發育聯系起來，可以更清楚地揭示有關基因在發育中的作用。

In addition , titration by turbidimetric immunoassay ( tia ) using sheep anti - human c3 serum revealed that amphioxus humoral fluid contained c3 - like component , and its concentration is about 1 . 17 mg / ml , which is comparable to c3 concentration in human or dog sera 此外，本實驗還運用免疫比濁法以綿羊抗人的補體3的抗血清檢測了文昌魚體液中的補體3濃度為1 . 17mg ml 。此濃度和人血清及狗血清中的c3濃度基本相當。

Rapd analysis was applied to study genetic diversity of amphioxus ( branchiostoma belcheri tsingtaoense ) in the test . total twenty - two samples , which are eleven males and eleven females were collected for use 本實驗首次采用隨機擴增多態dna ( randomamplifiedpolymorphicdna ， rapd )技術對青島文昌魚該群體雌雄各11條個體共22個樣本進行遺傳多樣性檢測。

Functional study on these novel genes is an on - going task in our laboratory . amphioxus amphihmgb encoding a hign - mobility - group ( hmg ) protein was identified from the gut cdna library of the amphioxus b . belcheri tsingtauense 文昌魚腸cdna表達文庫的成功構建，為從分子生物學水平研究文昌魚的進化與發育奠定了基礎，也是分離新基因的重要來源。

In the present study , a cdna expression library was constructed according to smart cdna library construction kit user manual from the adult amphioxus guts using pcdna3 eukaryotic expression vector 本文應用smart ~ ( tm ) cdnalibraryconstructionkit的方法，以成體文昌魚腸為研究材料，構建了以真核表達載體pcdna3為基礎的cdna表達文庫。

So , the cloning of amphioxus masp gene is very important in the development of masp gene and the immune system , even the origin of the vertebrates 因此，文昌魚masp基因的克隆對于研究中國海洋人學碩幾l . .學位論文功asp基因乃至免疫系統的進化來說是非常重要的，同時對研究脊椎動物的起源也具有十分重要的理論意義。

The reason for this is unknown at the present . possibly , cg - rich and at - rich regions in amphioxus dna are not as “ rich “ as those in the vertebrate dna , that is , amphioxus dna ha 雖然nogusa ( 1957 )認為b . belcheri存在xy型的性染色體，至于青島文昌魚的性染色體是xy型或zw型尚待深入研究。

1 . chromosome number ( 2n ) and fundamental number ( fn ) the chromosome number and karyotype of amphioxus branchiostoma belcheri tsingtauense were studied using embryonic cells of the animal 染色體數目( 2n )和臂數( fn )用青島文昌魚的胚胎細胞作材料，對其染色體數目和核型進行研究。