Reelin expression during embryonic brain development in lacertilian lizards.
J Comp Neurol
; 414(4): 533-50, 1999 Nov 29.
Article
em En
| MEDLINE
| ID: mdl-10531544
ABSTRACT
The expression of reelin mRNA and protein was studied during embryonic brain development in the lacertilian lizards L. viridis and L. galloti, by using radioactive in situ hybridization and immunohistochemistry. At all stages studied, high reelin expression was consistently found in the olfactory bulb, in the lateral cortex, and in neurons of the marginal zone and subplate of medial and dorsal cortical sectors. In the dorsal ventricular ridge (DVR), reelin expression was confined to deeply located, large cells which were more abundant in the caudal than the rostral part of the DVR. In the diencephalon, the ventral lateral geniculate complex and the perirotundal were strongly positive, whereas other nuclei were mostly negative. High reelin signal was associated with some layers in the tectum, with the torus semicircularis, cerebellar granule cell layers, and the ventral horn of the spinal cord. A more moderate signal was detected in the septal nuclei, striatum, retina, habenular nuclei, preoptic and periventricular hypothalamic components, and in reticular nuclei of the mid- and hindbrain. The medial and dorsal cortical plate and Purkinje cells were reelin-negative but expressed disabled-1 (Dab1) mRNA. When they are compared with reelin expression during mammalian brain development, our data reveal an evolutionarily conserved canvas of reelin expression, as well as significant differences, particularly in developing cortical fields. The developing lizard cortex differs from that of turtles, birds, crocodiles, and mammals in that it displays heavy reelin expression not only in neurons of the marginal zone that might be homologous to mammalian Cajal-Retzius cells, but also in subplate neurons. This difference in the pattern of reelin expression suggests that the elaborate radial organization of the lacertilian cortical plate, somewhat reminiscent of its mammalian counterpart, results from evolutionary convergence. Our data lend support to the hypothesis that the reelin signaling pathway played a significant role during cortical evolution.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tronco Encefálico
/
Moléculas de Adesão Celular Neuronais
/
Cerebelo
/
Proteínas da Matriz Extracelular
/
Prosencéfalo
/
Lagartos
Limite:
Animals
Idioma:
En
Revista:
J Comp Neurol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Bélgica