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博碩士論文 etd-0907110-235932 詳細資訊
Title page for etd-0907110-235932
論文名稱
Title
綠島四株尋常海綿完整粒線體DNA序列分析及親緣關係研究
Genomic and Phylogenetic Analyses of the Complete Mitochondrial DNA Sequences of Four Demospongiae Sponges in Green Island, Taiwan
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
155
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2010-04-16
繳交日期
Date of Submission
2010-09-07
關鍵字
Keywords
尋常海綿綱、親緣關係、粒線體DNA、桶狀海綿、黑皮海綿
phylogenetic analyses, Demospongiae, Xestospongia testudinaria, mitochondiral DNA, Terpios hoshinota
統計
Statistics
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中文摘要
海綿為後生動物中最早分歧出來的物種,在單細胞生物演化至多細胞生物的過程中扮演關鍵性的物種,其個體主要由細胞群所組成,尚未形成組織與器官。海綿動物的分布相當廣泛,種類超過15000種以上,其所分泌的二次代謝產物具有良好的抗癌與抗病毒活性,然而海綿依形態來進行分類及鑑種會因環境的影響而造成爭議。本研究以PCR及primer walking的方法針對綠島四種尋常海綿粒線體DNA完成定序,除了可供建立海綿基因資料庫外,更可用來探討海綿的演化與親緣關係。綠島四種尋常海綿Terpios hoshinota、Xestospongia testudinaria、Petrosia corticata及Suberea clavata粒線體全長分別為20,498、18,988、18,562及19,559個鹼基對,分別具有41段基因,其中包含2個核糖核酸基因 (rns, rnl)、14個蛋白質基因 (atp6、atp8-9、cox1-3、cob、nad1-6、nad4L) 及25個傳遞者核酸基因 (tRNA),除了Suberea clavata在部分粒線體基因群 (nad4L~tRNA-SerUGA) 以互補股進行轉譯外,其餘皆以正股進行轉譯。Xestospongia testudinaria與大西洋Xestospongia muta在形態學上歸類為不同種,但本研究發現兩個物種的序列差異有限,可能為同一種;而Suberea clavata與Aplysina fulva在形態學上歸類為不同科的海綿物種,但其序列上亦具有相當高的相似度,可能為同屬或同科的物種。由以上結果顯示,形態學在海綿物種的鑑定上仍具有瑕疵,因此須仰賴分子資訊方能準確的鑑定出海綿物種。
Abstract
Porifera (sponge) has been considered the earliest branching group of the metazoan crown, it plays an important role of evolution from protist to multicellular organisms. The sponges do not have tissues and organs. There are 15,000 species of sponges in the world. They contain a rich variety of secondary metabolites which may have the potential of becoming anticancer or antivirus drugs. The morphological characteristics of sponges may be affected by the environmental conditions and cause ambiguity and confusion in sponge identification. The complete mitochondrial DNAs of four Demospongiae sponges, Terpios hoshinota, Xestospongia testudinaria, Petrosia corticata, and Suberea clavata in Green Island were determined by PCR and primer walking. The sequences can be used for evolution and phylogenetic analyses. The complete mitochondrial genomes of the four sponges contain 20498 bp, 18988 bp, 18562 bp and 19559 bp, respectively. The genomes encode 2 rRNA genes (rns, rnl), 14 protein-coding genes (atp6, atp8-9, cox1-3, cob, nad1-6, and nad4L) and 25 tRNAs. All the genes of T. hoshinota, X. testudinaria, P. corticata are transcribed on the same strand. Whereas, some of the genes (nad 4L ~ tRNA-SerUGA) of S. clavata are encoded on the complementary strand. The results showed the differences between the mitochondrial DNA sequences of X. testudinaria and the Atlantic sponge, X. muta, are very limited, therefore, they may be reclassified as the same species. Meanwhile, S. clavata and Aplysina fulva are close phylogenetically. The conflict between molecular and morphology taxonomy should be re-examined.
目次 Table of Contents
摘要.......................................................................................i
Abstract...............................................................................ii
目錄....................................................................................iii
表目錄................................................................................iv
圖目錄.................................................................................v
附錄....................................................................................vi
一、前言...........................................................................1
1. 珊瑚礁生態系與海綿:...............................................1
2. 海綿的演化與特徵:...................................................2
3. 海綿的分類與親緣關係:...........................................3
4. 粒線體基因組特性與海綿粒線體基因研究:...........5
5. 研究目的:...................................................................7
6. 本研究海綿物種:.......................................................8
二、材料與方法.............................................................10
1. 樣品採集與保存:.....................................................10
2. 海綿粒線體DNA萃取:.............................................10
3. 引子設計、短片段增幅及產物純化:.....................12
4. Long PCR 及 Primer walking:.............................13
5. 序列與分子親緣關係分析:.....................................14
三、結果與討論.............................................................16
1. 粒線體基因組成與排序:.........................................16
2. 鹼基組成與密碼子的使用:.....................................18
3. 蛋白質基因與tRNA:................................................20
4. 無轉譯序列與rRNA:................................................22
5. 海綿分子親緣關係:.................................................25
6.海綿生命條碼:..........................................................26
7.形態分類與分子分類比較:......................................27
四、結論.........................................................................29
五、參考文獻.................................................................30
六、附錄.......................................................................113
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