由紐約大學(xué)進(jìn)化生物學(xué)教授Sandie Baldauf和Dundee大學(xué)生化教授Professor Pauline Schaap率領(lǐng)的研究小組獲得了現(xiàn)有的100種阿米巴蟲（social amoeba）的分子圖譜，由此現(xiàn)有的阿米巴蟲（social amoeba）全部家族譜系（family tree）成功繪制完成,，這是一個重大突破,，為研究地球上的生命形式進(jìn)化過程提供了重要線索。文章刊登于10月27日Science雜志,。
利用新得到的家譜,，研究人員設(shè)計出一種模型系統(tǒng)，用于解釋單細(xì)胞生命怎樣進(jìn)行信號傳遞的,，以及怎樣依據(jù)環(huán)境條件改變而相互作用產(chǎn)生多細(xì)胞結(jié)構(gòu)的,。先前一直沒有任何有關(guān)Dictyostelia阿米巴蟲的分子數(shù)據(jù)（Dictyostelia阿米巴蟲是一個巨大的、古老的阿米巴蟲亞家族）,。
阿米巴蟲是一組遺傳差異顯著的生命形式,，差異比真菌家族的還要大，與所有動物的差異相似,。進(jìn)化和信息傳遞研究在多細(xì)胞有機體中很難進(jìn)行,，阿米巴蟲為這兩種研究提供了極好的模型系統(tǒng)。
Dundee大學(xué)生命科科學(xué)院細(xì)胞分化和發(fā)育生物學(xué)教授Schaap說：“這給我們提供了分子水平研究物種進(jìn)化和突變的起點,。家譜的實用性使我們能夠重演產(chǎn)生多細(xì)胞的信號機制的進(jìn)化事件,，為我們鑒別調(diào)節(jié)大多數(shù)基礎(chǔ)發(fā)育事件的核心原始過程，提供了一件有力工具,。”
紐約大學(xué)生物學(xué)部Baldauf教授說：“我們研究植物和動物的進(jìn)化已經(jīng)有很長一段時間的歷史了,，但是我們所有的生態(tài)系統(tǒng)依賴于單細(xì)胞有機體,。如果想知道生命的基礎(chǔ)，我們應(yīng)該關(guān)注單細(xì)胞生命,。”
“阿米巴蟲是動物最親的單細(xì)胞親戚，因此弄清它們的工作和進(jìn)化機制非常重要,，有助于我們研究動物進(jìn)化過程,。我們已經(jīng)為研究生命模式進(jìn)化建立了一種新的模式系統(tǒng)。”
“我們已經(jīng)編撰了字典,，現(xiàn)在我們知道了單詞的意思,，但是我們還需要造句。”
研究小組通過擴大和對比所有已知的阿米巴蟲的高度保守基因,，繪制得到了阿米巴蟲家譜?，F(xiàn)有的家譜都是基于各個物種多細(xì)胞結(jié)構(gòu)的外觀。然而,，Dundee 和York大學(xué)研究人員獲得阿米巴蟲家譜完全植根于分子數(shù)據(jù),。通過將現(xiàn)有的阿米巴蟲的所有信息——細(xì)胞、多細(xì)胞形式,、行為等加入分子樹測繪分析,，顯示細(xì)胞特化增強，有機體大小是阿米巴蟲進(jìn)化的主要趨勢,。
Schaap教授及其同事目前正研究在產(chǎn)生新細(xì)胞類型和形態(tài)特征的進(jìn)化過程中,，重要基因的功能是怎樣改變的。Baldauf及其同事接下來的任務(wù)是研究阿米巴蟲的起源,，尋找新的種類,，并將它們按順組排列在家譜上。同時,，美國和德國的一些研究小組已獲得資助,，對York 和Dundee大學(xué)研究的阿米巴蟲的基因組進(jìn)行測序。
英文原文：
Scientists’ cell discovery unearths evolutionary clues
The full family tree of the species known as social amoebas has been plotted for the first time - a breakthrough which will provide important clues to the evolution of life on earth.
Researchers, headed by biochemist Professor Pauline Schaap, of the University of Dundee, and evolutionary biologist Professor Sandie Baldauf, of the University of York, have produced the first molecular ‘dictionary’ of the 100 or so known species of social amoeba.
Using this family tree, they have devised a model system to establish how single cell organisms communicate and interact to create multi-cellular structures in response to changing environmental conditions. Previously, there was almost no molecular data for social amoeba - Dictyostelia - which are a hugely diverse and ancient group.
Social amoebas are a group of organisms with a genetic diversity that is greater than that of fungi and similar to that of all animals. They offer an excellent experimental system for studying aspects of evolution and communication that are not easy to study in more complex multi-cellular organisms.
The York and Dundee teams have worked with field biologists in Germany, the US and Japan, and their research is published today (Friday 27th October 2006) in the prestigious international journal Science.
"This provides a starting point in allowing us to examine what happens at the molecular level as species evolve and mutate," said Professor Schaap, of the Division of Cell and Developmental Biology in the College of Life Sciences at Dundee.
"The availability of a family tree allows us to reconstruct the evolution of the signalling mechanisms that generate multicellularity. It also provides a powerful tool to identify core ancestral processes that regulate the most basic aspects of development."
Professor Baldauf, of the Department of Biology at York, said: "We have investigated the evolution of plants and animals for a very long time but our whole eco-system depends on single cell organisms. If we want to look at the fundamentals of life we have to look at single cell organisms."
"Amoebas are some of the closest single cell relatives of animals so understanding how they work and evolve is important because it helps us to understand how animals evolve. We have developed a new model system for the study of the evolution of forms."
"We have written the dictionary. Now we know what the words are -- but we still have to construct the sentences."
The research teams were able to build the family tree by amplifying and comparing highly conserved genes from all known species of social amoeba.
The existing family tree of the social amoeba was based on how the multicellular structures of each species look on the outside. However, this tree was completely uprooted by the molecular data gathered by the researchers in Dundee and York.
By plotting all existing information of the amoebas’ cellular and multi-cellular shapes and behaviour to the molecular tree, it appeared that increased cell specialization and organism size is a major trend in the evolution of social amoeba.
Professor Schaap and her team are now working to establish how the regulation and function of genes with important roles in development was altered and elaborated during the course of evolution to generate novel cell-types and morphological features.
The next step for Professor Baldauf and her team will be to investigate the origin of these amoebas, and also to search for new species and to establish their position on the family tree. Meanwhile, a number of research projects, including teams in the USA and Germany, have won sponsorship to sequence the genomes of social amoeba species identified by the work in York and Dundee.
The Dundee-York project was funded under the Biotechnology and Biological Sciences Research Council (BBSRC) CODE (COmparative DEvelopment) initiative and took four years to complete.
