Interaction between Otx2 and Gbx2 defines the organizing center for the optic tectum
Otx2 is expressed in the mesencephalon and prosencephalon, and Gbx2 is expressed in the rhombencephalon around stage 10. Loss-of-function studies of these genes in mice have revealed that Otx2 is indispensable for the development of the anterior brain segment, and that Gbx2 is required for the devel...
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Published in | Mechanisms of development Vol. 91; no. 1; pp. 43 - 52 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Ireland
Elsevier Ireland Ltd
01.03.2000
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Subjects | |
Online Access | Get full text |
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Summary: | Otx2 is expressed in the mesencephalon and prosencephalon, and
Gbx2 is expressed in the rhombencephalon around stage 10. Loss-of-function studies of these genes in mice have revealed that
Otx2 is indispensable for the development of the anterior brain segment, and that
Gbx2 is required for the development of the isthmus. We carried out gain-of-function experiments of these genes in chick embryos with a newly developed gene transfer system, in ovo electroporation. When
Otx2 was ectopically expressed caudally beyond the midbrain-hindbrain boundary (MHB), the alar plate of the metencephalon differentiated into the optic tectum instead of differentiating into the cerebellum. On the other hand, when
Gbx2 was ectopically expressed at the mesencephalon, the caudal limit of the tectum shifted rostrally. We looked at the effects of misexpression on the isthmus- and tectum-related molecules. Otx2 and Gbx2 interacted to repress each other's expression. Ectopic Otx2 and Gbx2 repressed endogenous expression of
Fgf8 in the isthmus, but induced
Fgf8 expression at the interface between
Otx2 and
Gbx2 expression. Thus, it is suggested that interaction between Otx2 and Gbx2 determines the site of
Fgf8 expression and the posterior limit of the tectum. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0925-4773 1872-6356 |
DOI: | 10.1016/S0925-4773(99)00262-2 |