| 摘要 |
Herein we describe, a candidate gene for the diffusible cell density signal is put through the classic test to validate its activity: ectopic expression in another cell type from another species, purification of the recombinant factor, and testing back on PAT cells to see if it acts like the original diffusible cell density signal. This classic approach is complicated by the finding that the cell type producing this protein binds a unique tissue-specific lipid cofactor and this composite molecule imparts a tissue-specific response. Previously, this mechanism was shown to rely on a diffusible factor with an affinity for the cell layer. |
