Roles of Pax-2 in initiation of the chick tectal development
Transplantation experiments have shown that the mes-metencephalic boundary (isthmus) acts as an organizer for the development of the optic tectum. We have cloned Pax-2 which is expressed in the isthmus. Previously it was shown that Pax-5, a member of the same Pax subfamily as Pax-2, transformed the...
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Published in | Brain research. Developmental brain research Vol. 116; no. 1; pp. 41 - 49 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Netherlands
Elsevier B.V
05.08.1999
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Subjects | |
Online Access | Get full text |
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Summary: | Transplantation experiments have shown that the mes-metencephalic boundary (isthmus) acts as an organizer for the development of the optic tectum. We have cloned
Pax-2 which is expressed in the isthmus. Previously it was shown that
Pax-5, a member of the same
Pax subfamily as
Pax-2, transformed the diencephalon into a tectum-like structure and induced isthmus- and tectum-related genes both in the mesencephalon and in the diencephalon. In order to define the distinct roles between
Pax-2 and
Pax-5 in development of the tectum, we expressed
Pax-2 ectopically in the mesencephalon and the diencephalon of E2 chick embryos by in ovo electroporation. Histological observation demonstrated that
Pax-2 transformed the diencephalon into a tectum-like structure. In
Pax-2, transfected embryos the expression of isthmus- and tectum-related genes such as
Fgf8 and
En-2 was induced in the diencephalon. However, neither
Fgf8 nor
En-2 expression was induced in the mesencephalon, making a striking contrast with the result of
Pax-5 misexpression. In E2 chick embryos, the mesencephalon is committed of its fate to differentiate into the tectum, but the diencephalon has plasticity on its fate. Moreover,
Pax-2 expression in the isthmus precedes
Pax-5 expression. Taking these results into consideration, it is suggested that
Pax-2 plays a crucial role in initiation of the tectal development, and that
Pax-5 functions to maintain the state of tectal differentiation. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0165-3806 |
DOI: | 10.1016/S0165-3806(99)00073-5 |