EGUCHI Goro Kumamoto University, President, 大学長 (80022581)
TSONIS Panag デイトン大学, 生物学部, 教授
小阪 美津子 岡崎国立共同研究機構, 基礎生物学研究所, 助手 (50270476)
MOCHII Makoto Okazaki Natl.Res.Inst., Natl.Inst.Basic Biol., Res.Assoc., 基礎生物学研究所, 助手 (90202358)
TSONIS PANAG デイトン大学, 生物学部, 教授
TSONIS Panagiotis Dayton Univ., Dept. Biol., Prof.
|Budget Amount *help
¥11,000,000 (Direct Cost : ¥11,000,000)
Fiscal Year 1997 : ¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1996 : ¥3,700,000 (Direct Cost : ¥3,700,000)
Fiscal Year 1995 : ¥3,700,000 (Direct Cost : ¥3,700,000)
Since this year is the last year of our collaborative studies, we concentrate our effort to the studies using urodelan amphibian species, Cynopus pyrrhogaster, the Japanese newt, and unstudied problems about the lens regeneration phenomenon, i.e. i) relationship between the aging of the iris pigmented epithelium and its regenerative ability to produce a new lens, ii) molecular basis of the localization of lens regenerative potency to the dorsal margin of the iris, and iii) expression pattern of the genes which are important in the early embryogenesis processes during the lens regeneration process in the adult iris.
i) We have induced continuous cell proliferation in the iris pigmented epithelial cells by successive surgeries of removing the lens from the same eye. After about 10th operations, we have observed a conspicuous delay in the process of the lens regeneration. This observation strongly suggests that the aging of the iris pigmented epithelial cells, which give rise to the regene
ration of the lens, may finally results in the loss of the potency of the lens regeneration.
ii) When the FGF,fibroblst growth factor, is continuously injected in excessive amount into the eye, the lens regeneration besides the dorsal most iris was induced. This result suggests that the stimulation of the FGF receptor may induce the inhibition of lens regeneration processes.
iii) Genes which have been indicated to take important roles in the tissue interactions in the early embryogenesis, such as pax-6, FGF-1, FGFR-1, FGFR-2, FGFR-3, prox-1, and ssh, were also evidenced to show characteristic expression patterns in the lens regeneration processes. This suggests that these genes are important in the regulation of tissue interactions in the lens regeneration processes.
Results indicated above are new and important results. The result i) has prompted us to start preparation of a set of newt individuals which are raised from fertilized eggs and have definitive record to their age, which makes it possible to study the relationship between aging and the lens regeneration potency more thoroughly. We have also started the analyzes at the level of the genes concerning the result ii). Part of the result iii) have already published. The results obtained in this year have, thus, made it possible to start a new series of investigations with higher scientific significance. Less