TY - JOUR
T1 - Interaction between Otx2 and Gbx2 defines the organizing center for the optic tectum
AU - Katahira, Tatsuya
AU - Sato, Tatsuya
AU - Sugiyama, Sayaka
AU - Okafuji, Tatsuya
AU - Araki, Isato
AU - Funahashi, Jun Ichi
AU - Nakamura, Harukazu
N1 - Funding Information:
We are indebted to Dr. Kunio Kitamura for the Otx2 probe, Dr. Marion Wassef for the Wnt-1 probe, Dr. Sumihare Noji for the Fgf8 probe, Dr. Hisato Kondo for pMiwSV, and Dr. Y. Wakamatsu for his critical reading of the manuscript. This work was supported by the Ministry of Education, Culture and Sports, Japan, the Agency of Science and Technology, Japan, and Japan Small and Medium Enterprise Corporation.
PY - 2000/3/1
Y1 - 2000/3/1
N2 - 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. (C) 2000 Elsevier Science Ireland Ltd.
AB - 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. (C) 2000 Elsevier Science Ireland Ltd.
KW - Gbx2
KW - Optic tectum
KW - Otx2
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U2 - 10.1016/S0925-4773(99)00262-2
DO - 10.1016/S0925-4773(99)00262-2
M3 - Article
C2 - 10704829
AN - SCOPUS:0033993556
VL - 91
SP - 43
EP - 52
JO - Cells and Development
JF - Cells and Development
SN - 2667-291X
IS - 1-2
ER -