Essential role for ERK2 mitogen-activated protein kinase in placental development.
BACKGROUND
Extracellular signal-regulated kinase 2 (ERK2) has been implicated in cell proliferation, differentiation, and survival. However, its role in vivo remains to be determined.


RESULTS
Here we show that the targeted disruption of the mouse ERK2 gene results in embryonic lethality by E11.5 and severe abnormality of the placenta. In these animals, the labyrinthine layer of the placenta is very thin and few foetal blood vessels are observed. ERK2 mutants can be rescued by the transgenic expression of ERK2, demonstrating that these abnormalities are caused by ERK2-deficiency. Although ERK2-deficient fetuses are much smaller than wild-type littermates, this seems to be secondary to malfunction of the placenta. When the placental defect is rescued by tetraploid-aggregation, ERK2-deficient foetuses grow as well as littermate controls.


CONCLUSIONS
These observations indicate that ERK2 is essential for placental development and suggest that ERK2 in the trophoblast compartment may be indispensable for the vascularization of the labyrinth.
Hatano
Naoya
N
Department of Pathology and Pathophysiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Japan.
Mori
Yoshiko
Y
Oh-hora
Masatsugu
M
Kosugi
Atsushi
A
Fujikawa
Takahiko
T
Nakai
Naoya
N
Niwa
Hitoshi
H
Miyazaki
Jun-ichi
J
Hamaoka
Toshiyuki
T
Ogata
Masato
M
D000818:Animals; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D017353:Gene Deletion; D005804:Genes, Lethal; D015151:Immunoblotting; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology*; D018919:Neovascularization, Physiologic / Q000502:physiology; D010920:Placenta / Q000098:blood supply / Q000196:embryology*; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism
D019950:Mitogen-Activated Protein Kinase 1