“組織器”組織的生成是胚胎學(xué)上的一個(gè)核心事件,。這一類細(xì)胞通常被稱為Spemann“組織器”，是由一個(gè)名為Nodal的變形生長(zhǎng)因子β配體所產(chǎn)生的信號(hào)作用中的一個(gè)不對(duì)稱現(xiàn)象在發(fā)育中的胚胎的背側(cè)誘導(dǎo)生成的,。 人們對(duì)這一不對(duì)稱性知之甚少?，F(xiàn)在，Martello等人發(fā)現(xiàn),，微RNA參與了這一過程,。兩個(gè)微RNA，即miR-15 和miR-16,，通過在Nodal受體Acvr2a的表達(dá)上產(chǎn)生一個(gè)背側(cè)偏向來(lái)限制該“組織器”的大小,。微RNA是小的單鏈RNA分子，它們幫助調(diào)控基因表達(dá),，它們的很多不同功能才剛剛開始被人們?nèi)嫜芯?。這項(xiàng)新的研究工作表明，微RNA在胚胎成形過程中的一個(gè)關(guān)鍵階段發(fā)揮作用,，它們是將β-catenin和Nodal信號(hào)作用聯(lián)系起來(lái)的一個(gè)環(huán)節(jié),。
原始出處:
Nature 449, 183-188 (13 September 2007) | doi:10.1038/nature06100; Received 5 February 2007; Accepted 18 July 2007; Published online 29 August 2007
MicroRNA control of Nodal signalling
Graziano Martello1, Luca Zacchigna1, Masafumi Inui1, Marco Montagner1, Maddalena Adorno1, Anant Mamidi1, Leonardo Morsut1, Sandra Soligo1, Uyen Tran2, Sirio Dupont1, Michelangelo Cordenonsi1, Oliver Wessely2 & Stefano Piccolo1
Department of Histology, Microbiology and Medical Biotechnologies, Section of Histology and Embryology, University of Padua, viale Colombo 3, 35126 Padua, Italy
Departments of Cell Biology & Anatomy and Genetics, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, Louisiana 70112, USA
Correspondence to: Stefano Piccolo1 Correspondence and requests for materials should be addressed to S.P. (Email: [email protected]).
MicroRNAs are crucial modulators of gene expression, yet their involvement as effectors of growth factor signalling is largely unknown. Ligands of the transforming growth factor- superfamily are essential for development and adult tissue homeostasis. In early Xenopus embryos, signalling by the transforming growth factor- ligand Nodal is crucial for the dorsal induction of the Spemann's organizer. Here we report that Xenopus laevis microRNAs miR-15 and miR-16 restrict the size of the organizer by targeting the Nodal type II receptor Acvr2a. Endogenous miR-15 and miR-16 are ventrally enriched as they are negatively regulated by the dorsal Wnt/-catenin pathway. These findings exemplify the relevance of microRNAs as regulators of early embryonic patterning acting at the crossroads of fundamental signalling cascades.
