Molecular biologists have characterized a class of intracellular proteins, termed transcription factors, which are rapidly synthesized in response to extracellular signals and subsequent changes in intracellular second-messenger systems, and which then serve to alter gene transcription. Transcription factors thus provide the molecular interface between gene and environmentally induced changes in cellular activity. The challenge for understanding the pathways by which maternal care alters gene expression is to describe the relevant extracellular and intracellular signals, including the target transcription factors.
