Evolutionary Origins of Notch Signaling in Early Development

Abstract

Notch signaling is known to play key roles in early embryonic development and inthe specification or patterning of germ layers in several lower organisms. Thus it issurprising that the removal of maternal and zygotic protein O-fucosyltransferase 1(Pofut1), an essential component of the canonical Notch signaling pathway, does notaffect early embryogenesis in the mouse.1 Mouse embryos lacking Pofut1 developnormally through blastogenesis to E8.0 when all three germ layers have formed.1 Herewe summarize roles for Notch signaling in early embryonic development of severalspecies, and discuss the potential evolutionary origins of these roles. We propose thatNotch signaling might have first been used in the common ancestor of the metazoa forcertain advanced developmental processes such as segmentation, and only later inevolution been co-opted for use at early stages of embryogenesis in some organisms.