Transcription factor NF 1 expression in involuting mammary gland.

Transcripts of each of the four NF1 genes (NF1 A, B, C (CTF/NF1) and X) are expressed in both lactating and involuting mouse mammary gland but there is an indication that increased expression of an NF1 C (CTF/NF1) transcript accompanies early involution. The involution-associated 74 kD NF1 and the 114 kD lactation-associated NF1 are recognised by an anti-NF1 C-specific antibody that does not cross-react with other NF1 proteins. It is most likely that this lactation/involution switch in NF1 factors represents a change in expression of NF1 C (CTF/NF1) proteins.