Anchor cell

The anchor cell is a type of cell responsible for patterning during development in multicellular organisms. The anchor produces a signal which nearby equipotent precursor cells receive. A precursor cells may produce one or more secondary signals, which are received by other precursors. The combination of these signals--and variations in concentration--is used by these cells to determine their ultimate fate.

Models

1. In Graded Signaling, a concentration gradient of some molecule--proportional to the distance from the anchor cell--acts to signal the precursor cell. Different concentrations produce different fates.
2. In Sequential Signaling, the anchor cell initiates a signaling cascade which begins in nearby precursors and spreads to those further away.
3. In Combined Signaling, the graded and sequential models are merged. Either concentration or a signaling cascade may specify precursor cell fate.