蠑螈等動物具有斷肢再生的能力,，不過是什么保證了斷腿的地方不會長出一條尾巴呢？英國《自然》雜志7月2日刊登的一項研究說,，蠑螈的各種細(xì)胞具有記憶所屬機體組織的能力,，可良好地“專業(yè)分工”，幫助斷肢再生,。
《自然》雜志刊登的這項由德國和美國等國科學(xué)家進(jìn)行的研究指出,，研究人員利用基因技術(shù)向一種名為墨西哥鈍口螈的蠑螈體內(nèi)植入綠色熒光蛋白，再將相關(guān)細(xì)胞移植到有斷肢的墨西哥鈍口螈體內(nèi),，這樣就可以通過追蹤熒光蛋白觀察斷肢再生的過程,。
研究發(fā)現(xiàn)，蠑螈斷肢創(chuàng)口周圍的皮膚,、肌肉,、骨骼等各種細(xì)胞會聚集到一起，從成體細(xì)胞反向變?yōu)?ldquo;幼年”細(xì)胞,，形成具有再生能力的芽基細(xì)胞群,。盡管這些芽基細(xì)胞看起來都差不多，但它們都記住了各自的來源,，從肌肉細(xì)胞而來的仍再生為肌肉細(xì)胞,，從神經(jīng)鞘細(xì)胞而來的仍再生為神經(jīng)鞘細(xì)胞。
更令人驚奇的是,，從蠑螈肢體末端取下的軟骨細(xì)胞,，在移植到上臂部位后，居然慢慢移到了與其原有位置相對應(yīng)的地方,，證明這種細(xì)胞具有記憶位置的功能,。
醫(yī)學(xué)界一直在研究蠑螈、壁虎等動物的斷肢再生能力,，以發(fā)現(xiàn)幫助人類斷肢再生的途徑,。研究人員認(rèn)為,，本次發(fā)現(xiàn)對于再生類藥物的研發(fā)具有重要意義。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 460, 60-65 (2 July 2009) | doi:10.1038/nature08152
Cells keep a memory of their tissue origin during axolotl limb regeneration
Martin Kragl1,3,5,6, Dunja Knapp1,3,5, Eugen Nacu1,3, Shahryar Khattak1,3, Malcolm Maden4, Hans Henning Epperlein2 & Elly M. Tanaka1,3
1 Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108,
2 Institute of Anatomy, Medical Faculty, University of Technology Dresden, Fetscherstrasse 74,
3 Center for Regenerative Therapies, University of Technology Dresden, Tatzberg 47/49, 01307 Dresden, Germany
4 The Regeneration Project, McKnight Brian Institute, University of Florida, Rm 326 Bartram Hall, Gainesville, Florida 32611, USA
5 These authors contributed equally to this work.
6 Present address: Institute of Metabolic Physiology, Heinrich-Heine-Universit?t Düsseldorf, Universit?tsstrasse 1, 40225 Düsseldorf, Germany.
During limb regeneration adult tissue is converted into a zone of undifferentiated progenitors called the blastema that reforms the diverse tissues of the limb. Previous experiments have led to wide acceptance that limb tissues dedifferentiate to form pluripotent cells. Here we have reexamined this question using an integrated GFP transgene to track the major limb tissues during limb regeneration in the salamander Ambystoma mexicanum (the axolotl). Surprisingly, we find that each tissue produces progenitor cells with restricted potential. Therefore, the blastema is a heterogeneous collection of restricted progenitor cells. On the basis of these findings, we further demonstrate that positional identity is a cell-type-specific property of blastema cells, in which cartilage-derived blastema cells harbour positional identity but Schwann-derived cells do not. Our results show that the complex phenomenon of limb regeneration can be achieved without complete dedifferentiation to a pluripotent state, a conclusion with important implications for regenerative medicine.
