Journal of Dental Research, Vol 79, 926-929, Copyright © 2000 by International & American Associations for Dental Research Online Journals
Low levels of GRP-Ca expression in transgenic mice
K. G. Ten Hagen and M. M. Balys
Center for Oral Biology, Aab Institute of Biomedical Sciences, University of Rochester Medical Center, NY 14642, USA. Kelly_TenHagen@urmc.rochester.edu
The GRP-Ca gene of the rat encodes a member of the
glutamine/glutamic-acid-rich protein (GRP) family. This gene is expressed
in a highly tissue-specific fashion, with transcription being found only in
the acinar cells of the submandibular gland (SMG). To begin to define the
cis-acting elements governing GRP-Ca expression, we constructed transgenic
mice containing the rat GRP-Ca gene plus 9.5 kb of 5' genomic sequence and
1 kb of 3 genomic sequence. Expression of GRP-Ca was detectable in progeny
from only 1 of 3 independent founders. Expression levels of the transgenic
GRP-Ca were much lower than the native GRP-Ca found in the rat SMG.
Furthermore, GRP-Ca in transgenic mice was not tissue-specifically
expressed, being found in both the SMG/SLG complex and the liver. These
results indicate that the genomic region of GRP-Ca included in these
transgenic mice is not sufficient to confer the high levels of
tissue-specific expression seen in the rat.
