Conservation of K1 immunoreactivity against early cortical neurones in the vertebrate telencephalon.
A monoclonal antibody, K1, immunostains neurones generated earliest in the rat neocortex. The K1 immunoreactivity was found in both mouse and human embryos. In the human marginal zone, the subpial granular layer and the inner sublayer were stained at the 19th and 20th week of gestation, respectively. Western blot analysis revealed that the K1 immunoreactivity was conserved in a variety of vertebrates. While a protein of low molecular weight (200 kDa) reacted dominantly in an amphibian (Xenopus laevis) and a reptile (Agkistrodon blomhoffii), proteins of higher molecular weights (280 and 290 kDa) reacted dominantly in mammals (mouse, rat and macaque). In the brain of the reptile (Lacerta triliniata) embryo, K1 stained a marginal part of the superficial molecular layer in the dorsal cortex that is probably homologous to the mammalian marginal zone in the neocortex. In the chick embryo at the 8th day of incubation, the immunoreactivity was observed on neurones generated earliest in the dorsal cortex but not in the superficial molecular layer. The dorsal ventricular ridge and pallial thickening in either the reptile or chick were not stained. The K1 antigen could be a good marker for evolutional study of the mammalian neocortex.
Ishii
K
K
Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Hirata
Y
Y
Ogawa
Y
Y
Uyemura
K
K
D017836:Agkistrodon; D000818:Animals; D000942:Antigens, Bacterial; D016667:Bacterial Capsules; D002642:Chick Embryo; D005260:Female; D006801:Humans; D008251:Macaca; D051379:Mice; D019579:Neocortex / Q000196:embryology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D013045:Species Specificity; D013687:Telencephalon / Q000196:embryology / Q000378:metabolism*; D014981:Xenopus
D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; C036962:capsular polysaccharide K1