生物谷： 瑞典Umeå大学的一组科学家发现了相同信号分子决定眼球和嗅觉细胞形成的独特机理。他们的结果发表在最新的《发育细胞杂志》（Developmental Cell）上。
嗅觉和视觉是两个至关重要的感官系统，使我们有能力感知我们周围的世界。目前已经确定嗅觉是通过嗅觉黏膜发展的，而视觉依靠的是眼球的形成。
嗅觉黏膜和眼球都是在胎儿时期形成的，但是直到现在人们才精确地知道是什么信号管理着它们的形成。Umeå大学的研究小组发现了同样的信号分子管理着嗅觉细胞和眼球的形成。
这项研究还发现，短时间暴露在信号下的细胞会变成嗅觉细胞，而长时间暴露在信号下的细胞会变成眼球的透镜状细胞。而通常的机理，是不同浓度的信号分子会导致形成不同的细胞。
同样的信号下，是暴露时间的不同而不是浓度的不同导致形成不同的感觉器官，这一发现对于我们理解在胎儿期不同种类的细胞是怎样形成的有着重要的作用。 （教育部科技发展中心）
原文链接：http://www.physorg.com/news103451117.html
原始出处:
Developmental Cell, Vol 13, 141-149, 03 July 2007
Short Article
Time of Exposure to BMP Signals Plays a Key Role in the Specification of the Olfactory and Lens Placodes Ex Vivo
My Sjödal,1 Thomas Edlund,1 and Lena Gunhaga1,
1 Umeå Center for Molecular Medicine, Building 6M, 4th floor, Umeå University, S-901 87 Umeå, Sweden
Corresponding author
Lena Gunhaga
Lena.Gunhaga@ucmm.umu.se
Spatial gradients of extracellular signals are implicated in the patterning of many different tissues. Much less is known, however, about how differences in time of exposure of progenitor cells to patterning signals can influence different cell fates. Bone morphogenetic protein (BMP) signals are known to pattern embryonic ectoderm. The olfactory and lens placodes are ectodermal structures of the vertebrate head. By using an explant assay of placodal cell differentiation, we now provide evidence that BMP signals are required and sufficient to induce olfactory and lens placodal cells from progenitor cells located at the anterior neural plate border. We also provide evidence that time of exposure of these progenitor cells to BMP signals plays a key role in the differential specification of olfactory and lens placodal cells.
