Gs. Ji et al., EPIDERMAL GROWTH-FACTOR SIGNALING AND MITOGENESIS IN PLCG1 NULL MOUSEEMBRYONIC FIBROBLASTS, Molecular biology of the cell, 9(4), 1998, pp. 749-757
Gene targeting techniques and early mouse embryos have been used to pr
oduce immortalized fibroblasts genetically deficient in phospholipase
C (PLC)-gamma 1, a ubiquitous tyrosine kinase substrate. Plcg1(-/-) em
bryos die at embryonic day 9; however, cells derived from these embryo
s proliferate as well as cells from Plcg1(+/+) embryos. The null cells
do grow to a higher saturation density in serum-containing media, as
their capacity to spread out is decreased compared with that of wild-t
ype cells. Ln terms of epidermal growth factor receptor activation and
internalization, or growth factor induction of mitogen-activated prot
ein kinase, c-fos, or DNA synthesis in quiescent cells, PLcg1(-/-) cel
ls respond equivalently to PLcg1(+/+) cells. Also, null cells are able
to migrate effectively in a wounded monolayer. Therefore, immortalize
d fibroblasts do not require PLC-gamma 1 for many responses to growth
factors.