| Project/Area Number |
60540466
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物発生・生理学
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| Research Institution | Kyushu University |
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Principal Investigator |
YAMANA Kiyotaka Department of Biology, Faculty of Science, Kyushu University, 理学部, 教授 (20037162)
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| Co-Investigator(Kenkyū-buntansha) |
NOMURA Kazuya Department of Biology, Faculty of Science, Kyushu University, 理学部, 助手 (30150395)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | regulation / developmental program / amphibian / half embryo / 培養液 |
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| Research Abstract |
We have already shown that lateral halves of 8-cell embryos of Xenopus laevis underwent regulative development to become normally proportioned tailbud embryos under certain culture conditions, whereas they failed to regulate their own pattern and developed into half tailbud embryos (lacking the lateral half of the body) under different conditions. The purpose of the present study is (1) to establish the culture conditions under which regulation can or cannot occur and (2) to study the mechanism by which regulation can or cannot occur.
To prepare a series of culture media of different salt concentrations, 10% Steinberg solution was supplemented with different amounts of NaCl. Half embryos of 8-cell embryos were cultured in the above media until controls reached the tailbud stage. External morphology of the embryos derived from half embryos were examined during culture, and their histological sections were also examined.
Results obtained show that the higher the salt concentration of a culture medium, the higher the frequency of half tailbud embryos. In the half tailbud embryos one of pairs of organs, such as an eye, was missing, and no segmentation of somites occurred. Morphological examination during culture has revealed that formation of half tailbud embryos was preceded by incomplete invagination, i. e., blastopores closed incompletely and the surface of the embryos was only partially covered with epidermis and parts of mesoderm and endoderm being left exposed. Below a certain salt concentration half tailbud embryos never appeared. The results of our previous experiments can be interpreted as being due to a high salt concentration of the medium used.
Thus, it has become highly likely that the observed failure in regulation of developmental program is due to incomplete invagination which is preferentially caused in a culture medium of a higher salt concentration.
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