Skip to main content
. Author manuscript; available in PMC: 2015 Jul 1.
Published in final edited form as: Dev Biol. 2014 Apr 12;391(1):1–16. doi: 10.1016/j.ydbio.2014.04.001

Figure 8.

Figure 8

Cell contact signaling. A feedforward loop controls the expression of GBF dependent genes. GBF is a DNA binding protein that regulates expression of many developmental genes including the tgr genes that encode transmembrane proteins for cell-cell adhesion. The Tgr proteins are highly polymorphic in nature and act in intercellular signaling to indicate the level of kinship. If TrgB and TgrC are compatible in adjacent cells, then the GBF dependent developmental genes are expressed as long as GBF is also functional. Such a feedforward loop acts as a low pass filter to avoid reacting to short lived fluctuations in the signals.