日本研究人員在新一期《自然》雜志網(wǎng)絡(luò)版上發(fā)表論文說，他們發(fā)現(xiàn)一種無脊椎動物——海鞘的神經(jīng)細(xì)胞生成機(jī)制,，該成果有助于研究干細(xì)胞的分化過程,。
海鞘是尾索動物亞門海鞘綱的總稱,，與脊椎動物亞門同屬脊索動物門,。
日本筑波大學(xué)下田臨海實(shí)驗(yàn)中心副教授笹倉靖德等研究人員報(bào)告說，他們應(yīng)用轉(zhuǎn)基因技術(shù),，讓海鞘幼體中樞神經(jīng)系統(tǒng)的細(xì)胞在紫外線照射下發(fā)出紅光,，然后觀察海鞘幼體發(fā)育為成體的整個過程。他們發(fā)現(xiàn),，海鞘幼體中樞神經(jīng)系統(tǒng)中的一種神經(jīng)膠質(zhì)細(xì)胞會一直留存到成體中,，并在成體中制造神經(jīng)細(xì)胞。
神經(jīng)膠質(zhì)細(xì)胞具有支持并滋養(yǎng)神經(jīng)細(xì)胞,，吸收和調(diào)節(jié)某些活性物質(zhì)等作用,。哺乳動物的中樞神經(jīng)系統(tǒng)中存在能分化成神經(jīng)細(xì)胞的干細(xì)胞，它們有望用于修復(fù)受損的神經(jīng),。
笹倉靖德指出,，海鞘在遺傳上與脊椎動物有相近之處，而前者中樞神經(jīng)系統(tǒng)的細(xì)胞只有大約300個,。對這類擁有簡單中樞神經(jīng)系統(tǒng)的動物進(jìn)行研究,，有助于人們研究從干細(xì)胞分化生成神經(jīng)細(xì)胞的整套機(jī)制。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09631
Ependymal cells of chordate larvae are stem-like cells that form the adult nervous system
Takeo Horie,Ryoko Shinki,Yosuke Ogura,Takehiro G. Kusakabe,Nori Satoh& Yasunori Sasakura
In ascidian tunicates, the metamorphic transition from larva to adult is accompanied by dynamic changes in the body plan. For instance, the central nervous system (CNS) is subjected to extensive rearrangement because its regulating larval organs are lost and new adult organs are created1. To understand how the adult CNS is reconstructed, we traced the fate of larval CNS cells during ascidian metamorphosis by using transgenic animals and imaging technologies with photoconvertible fluorescent proteins2. Here we show that most parts of the ascidian larval CNS, except for the tail nerve cord, are maintained during metamorphosis and recruited to form the adult CNS. We also show that most of the larval neurons disappear and only a subset of cholinergic motor neurons and glutamatergic neurons are retained. Finally, we demonstrate that ependymal cells of the larval CNS contribute to the construction of the adult CNS and that some differentiate into neurons in the adult CNS. An unexpected role of ependymal cells highlighted by this study is that they serve as neural stem-like cells to reconstruct the adult nervous network during chordate metamorphosis. Consequently, the plasticity of non-neuronal ependymal cells and neuronal cells in chordates should be re-examined by future studies3, 4.
