日本東京大學(xué)研究人員用簡單的有機(jī)化合物合成了能夠自我增殖的人造細(xì)胞。這種增殖方式類似大腸桿菌的細(xì)胞有望成為探索生物起源的線索,。
取得這項成果的是東京大學(xué)名譽教授菅原正等組成的團(tuán)隊,。研究人員先利用類似界面活性劑的分子、催化劑以及水制成雙層膜,。然后把混有從大腸桿菌提取的DNA（脫氧核糖核酸）和DNA合成酶的水注入雙層膜,，讓膜包裹著含DNA的水，形成外觀像細(xì)胞的直徑1至10微米的球體,。
之后,，讓球體內(nèi)液體的溫度升高至95攝氏度再下降到65攝氏度。在不斷重復(fù)這種溫度變化的過程中,，加上酶的效用,，DNA成功復(fù)制，經(jīng)過20次反復(fù),，DNA增加至100多萬倍,。
DNA增加后，再添加制作膜的有機(jī)化合物,，部分DNA就附著到雙層膜內(nèi)壁,，人造細(xì)胞開始膨脹，約4分鐘后如同天然細(xì)胞分裂一樣從中間斷裂,，形成新細(xì)胞,。在實驗中一個人造細(xì)胞能分裂出8到10個細(xì)胞。
據(jù)介紹,，雖然在這次研究中使用來自于大腸桿菌的DNA,，不過即使使用人工合成的DNA，人造細(xì)胞也能實現(xiàn)同樣的增殖,。
相關(guān)研究論文發(fā)表在5日的英國《自然—化學(xué)》雜志網(wǎng)絡(luò)版上,。(生物谷 Bioon.com）
doi:10.1038/nchem.1127
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PMID:
Self-reproduction of supramolecular giant vesicles combined with the amplification of encapsulated DNA
Kensuke Kurihara; Mieko Tamura; Koh-ichiroh Shohda; Taro Toyota; Kentaro Suzuki; Tadashi Sugawara
The construction of a protocell from a materials point of view is important in understanding the origin of life. Both self-reproduction of a compartment and self-replication of an informational substance have been studied extensively, but these processes have typically been carried out independently, rather than linked to one another. Here, we demonstrate the amplification of DNA (encapsulated guest) within a self-reproducible cationic giant vesicle (host). With the addition of a vesicular membrane precursor, we observe the growth and spontaneous division of the giant vesicles, accompanied by distribution of the DNA to the daughter giant vesicles. In particular, amplification of the DNA accelerated the division of the giant vesicles. This means that self-replication of an informational substance has been linked to self-reproduction of a compartment through the interplay between polyanionic DNA and the cationic vesicular membrane. Our self-reproducing giant vesicle system therefore represents a step forward in the construction of an advanced model protocell.
