Ellies D L, Church V, Francis-West P, Lumsden A
MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, SE1 1UL, UK.
Development. 2000 Dec;127(24):5285-95. doi: 10.1242/dev.127.24.5285.
In the avian hindbrain, the loss of premigratory neural crest cells from rhombomeres 3 and 5 (r3, r5) through programmed cell death contributes to the patterning of emigrant crest cells into three discrete streams. Programmed cell death is induced by the upregulation of Bmp4 and Msx2 in r3 and r5. We show that cSFRP2, a WNT antagonist, is expressed in the even-numbered rhombomeres and that over-expression of cSfrp2 inhibits Bmp4 expression in r3 and r5, preventing programmed cell death. By contrast, depleting cSFRP2 function in r4 results in elevated levels of Msx2 expression and ectopic programmed cell death, as does overexpression of Wnt1. We propose that programmed cell death in the rhombencephalic neural crest is modulated by pre-patterned cSfrp2 expression and a WNT-BMP signalling loop.
在鸟类后脑，通过程序性细胞死亡，来自菱脑节3和5（r3、r5）的迁移前神经嵴细胞的缺失有助于将迁移的嵴细胞模式化为三个离散的流。程序性细胞死亡是由r3和r5中Bmp4和Msx2的上调诱导的。我们发现，WNT拮抗剂cSFRP2在偶数菱脑节中表达，并且cSfrp2的过表达抑制r3和r5中Bmp4的表达，从而防止程序性细胞死亡。相比之下，在r4中耗尽cSFRP2功能会导致Msx2表达水平升高和异位程序性细胞死亡，Wnt1的过表达也会导致这种情况。我们提出，菱脑嵴中的程序性细胞死亡受预先模式化的cSfrp2表达和WNT - BMP信号回路调节。
