Developmental regulation of activated ERK expression in the spinal cord and dorsal root ganglion of the chick embryo.
Mitogen-activated protein kinases (MAPKs) are involved in the intracellular pathways that respond to various extracellular signals. Extracellular signal-regulated kinase (ERK) is a member of MAPKs and has various functions in neural development. However, the in vivo distribution of the activated form of ERK (p-ERK) in the developing nervous system is not well understood. Here, we investigated the expression of p-ERK in the spinal cord and dorsal root ganglion (DRG) of chick embryos. In the spinal cord, p-ERK-positive cells appeared in the ventral ventricular zone on embryonic day 4 (E4). From E6 onward, they appeared in the gray matter and in the white matter, suggesting migration from the ventricular zone. A double labeling method revealed that these p-ERK-positive cells included oligodendrocyte precursors. In the dorsal horn, p-ERK-positive small cells appeared on E6. Subsequently, the positive cells in the dorsal horn increased transiently in number and then decreased markedly by E10. Motoneurons also expressed p-ERK transiently on E7. In the DRG, weak p-ERK immunoreaction appeared in the ventrolateral region on E5. From E6, the immunoreactivity became stronger and by E9 intense p-ERK-positive cells were observed throughout the DRG. These data provide a neuroanatomical framework to begin to examine the in vivo role of ERK in neural development.
Kato
Taro
T
Department of Anatomy, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba 305-8575, Japan.
Ohtani-Kaneko
Ritsuko
R
Ono
Katsuhiko
K
Okado
Nobuo
N
Shiga
Takashi
T
D000818:Animals; D015153:Blotting, Western; D002642:Chick Embryo; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis*; D005727:Ganglia, Spinal / Q000196:embryology* / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism; D009836:Oligodendroglia / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000196:embryology* / Q000378:metabolism
D048049:Extracellular Signal-Regulated MAP Kinases