Developmental regulation of expression of multiple gamma-glutamyl transpeptidase mRNAs in the postnatal rat epididymis.

Northern blot analysis was used to examine the pattern of gamma-glutamyl transpeptidase (GGT) mRNA expression during postnatal development of the rat epididymis. Multiple GGT mRNAs were detected in whole epididymides ranging in size from 2.2 to 2.5 kb. Expression of GGT mRNAs was low at birth and remained constant until postnatal day 8. From days 8-12, expression of GGT mRNAs decreased, then increased from day 14 thereafter until adult levels were attained. RNase protection analyses identified these GGT transcripts as mRNAsII, III and IV, corresponding to previously characterized GGT mRNAs that are transcribed from independent promoters. These results demonstrate that expression of multiple GGT mRNAs is regulated during postnatal development of the rat epididymis.