En-2 regulates the expression of the ligands for Eph type tyrosine kinases in chick embryonic tectum
The retinotectal projection map is organized in a precise retinotopic order, so that the temporo-nasal axis of the retina corresponds to the rostro-caudal axis of the tectum. en-1 and en-2, homologues of the Drosophila segment polarity gene engrailed, are expressed in a gradient along the rostro-cau...
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Published in | Neuroscience research Vol. 27; no. 3; pp. 211 - 217 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Ireland
Elsevier Ireland Ltd
01.03.1997
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Subjects | |
Online Access | Get full text |
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Summary: | The retinotectal projection map is organized in a precise retinotopic order, so that the temporo-nasal axis of the retina corresponds to the rostro-caudal axis of the tectum.
en-1 and
en-2, homologues of the
Drosophila segment polarity gene
engrailed, are expressed in a gradient along the rostro-caudal axis of the tectal anlage, and are suggested to confer caudal characteristics as the results of transplantation and ectopic
engrailed (
en) expression. Recently the ligands for Eph type receptor tyrosine kinases have been shown to be expressed strongly at the caudal tectum and play a role in retinotectal map formation by repulsing the temporal retinal fibers. Using the system of replication competent retroviral vector,
en-2 RCAS (A/B), we misexpressed
en-2 on the tectum.
Elf-1 or
RAGS was induced at the ectopic En-2 sites. The present results have shown that En-2 can regulate expression of both
Elf-1 and
RAGS. This suggests that the cells which express
en at the early stage of tectum development acquire positional specificity as `caudal' tectum, and these cells may later express the ligands for Eph type receptor tyrosine kinases. Therefore the temporal retinal fibers which have the receptors are repelled when they meet the ligands on the tectum. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0168-0102 1872-8111 |
DOI: | 10.1016/S0168-0102(96)01151-0 |