Differential expression of connexin 43 in mouse mammary cells.
In this study we have employed suppressive subtractive hybridization (SSH) analysis to investigate differential gene expression in primary mouse mammary epithelial cells (PMMEC) cultured under mildly apoptotic/quiescent and differentiating conditions. Among a small group of genes whose expression was differentially regulated was connexin 43. In vitro, connexin 43 mRNA and protein were detectable in PMMEC cultured under proliferative or mildly apoptotic conditions. The level of connexin 43 mRNA expression in vivo was also investigated. High levels of expression were found to be associated with the periods of greatest glandular plasticity (pubertal expansion of the mammary tree, early pregnancy and during early involution). Thus, terminally differentiated cells in vivo and in vitro did not express connexin 43 mRNA suggesting that connexin 43 expression, and perhaps facilitated gap junction communication, is associated with undifferentiated progenitor cell populations.
Lambe
Teresa
T
UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Finlay
Darren
D
Murphy
Madeline
M
Martin
Finian
F
D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D018031:Connexin 43; D017630:Connexins / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000378:metabolism*; D051379:Mice; D009693:Nucleic Acid Hybridization / Q000379:methods; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D012741:Sexual Maturation
D018031:Connexin 43; D017630:Connexins; D012333:RNA, Messenger; C471698:connexin 43alpha1, mouse