Regulation of Purkinje cell alignment by reelin as revealed with CR-50 antibody.
Cerebellar Purkinje cells are generated in the ventricular zone, migrate outward, and finally form a monolayer in the cortex. In reeler mice, however, most Purkinje cells cluster abnormally in subcortical areas. Reelin, the candidate reeler gene product recognized by the CR-50 monoclonal antibody, is concentrated in a cortical zone along which Purkinje cells are aligned linearly, implying that it may regulate their alignment. We used an in vitro system and a transplantation approach to analyze the function of Reelin. Explant culture for 7 d of cerebella isolated from wild-type and reeler mice at embryonic day 13 (E13) reproduced in a phenotype-dependent manner the two distinct arrangement patterns (linear vs clustered) of Purkinje cells. Extensive CR-50 binding to wild-type explants converted the linear pattern into a reeler-like, clustered pattern. On the other hand, when reeler explants lacking Reelin were crowned with an artificial layer of Reelin+ granule cells, some Reelin molecules were distributed into a superficial zone of the reeler explants, and Purkinje cells formed a linear pattern along the Reelin-rich overlay. This "rescue" effect was also inhibited by CR-50. Hence, Reelin is involved in the Purkinje cell alignment, and the lack of this activity may explain the malformation in reeler cerebella. We further injected Reelin+ granule cells into the fourth ventricle of E12-13 mice. Extensive incorporation of the injected Reelin+ cells into the ventricular zone, but not of Reelin- cells, forced Purkinje cells of the host cerebella to form an aberrant layer, suggesting that premigratory Purkinje cells may already be responsive to Reelin or Reelin-related signals.
Miyata
T
T
Molecular Neurobiology Laboratory, Tsukuba Life Science Center, The Institute of Physical and Chemical Research (RIKEN), Tsukuba, Ibaraki 305, Japan.
Nakajima
K
K
Mikoshiba
K
K
Ogawa
M
M
D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D015816:Cell Adhesion Molecules, Neuronal / Q000032:analysis* / Q000235:genetics*; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured / Q000737:chemistry; D016326:Extracellular Matrix Proteins / Q000032:analysis* / Q000235:genetics*; D005260:Female; D005333:Fetus / Q000166:cytology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D051379:Mice; D008818:Mice, Neurologic Mutants; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000502:physiology; D010641:Phenotype; D011247:Pregnancy; D011689:Purkinje Cells / Q000737:chemistry* / Q000166:cytology / Q000637:transplantation; D000091042:Reelin Protein; D012697:Serine Endopeptidases; D015398:Signal Transduction / Q000502:physiology
D000911:Antibodies, Monoclonal; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases