| 1.Research Institution | Kyushu University | |
| 2.Research Area | Life Sciences | |
| 3.Research Field | Organism Constructing Mechanisms (Reproduction and Development) | |
| 4.Term of Project | FY 1997 〜 FY 2001 | |
| 5.Project Number | 97L00401 | |
| 6.Title of Project | Mechanisms of Behavioral Pattern Development and Determination of Body Sizes and Cell Sizes |
| Name | Institution,Department | Title of Position |
| YASUMI, OHSHIMA | Kyushu University, Graduate School of Sciences | Professor |
8.Core Members
| Names | Institution,Department | Title of Position |
| RYUJI, HOSONO | Kanazawa University, Faculty of Medicine | Professor |
| HIROAKI, KAGAWA | Okayama University, Faculty of Science | Professor |
| KIYOSHI, KITA | The University of Tokyo, Graduate School of Medicine | Professor |
9.Summary of Research Results
|
(A) Mechanisms of thermotaxis: Distribution and movement of worms on a temperature gradient
were re-examine6d in detail. The results showed much wider distribution up t a 10℃ range, absence of
both taxis to a growth temperature and avoidance of starving temperature, and avoidance of
warm temperatures. These results suggest a model involving a single thermosensony pathway in
contrast to the previous model. (B)Mechanisms of axonal elongation: UNC-51 was expressed in cultured cells and was shown to phosphorylate tubulin and actin in vitro, suggesting that UNC-51 regulates axonal elongation through control of dynamics of microtubules and actin cytoskeletons. (C) Identification and analysis of genes involved in learning: A system to examine habituation learning on mechanical stimulation by a tap or a touch was developed, which allowed isolation of several mutants abnormal in the habitation such as hab-1, 2 and 3. hab-1 gene was identified to encode a submit of mitochondoria complex 1. (D) Functional analysis of genes involved in excitation-contraction coupling in the muscles. An embryonic lethal mutation pat-10 was found at two positions within the troponic C gene. Troponin C molecules carrying each single mutation lacked binding activities to Ca++ or troponin I. This is the first demonstration of a role of troponin C both in embryonic development and muscle formation. (E) Mechanisms of determination of body and cell sizes: About 20 mutants with a body volume increased by 50-100% were isolated. Four of them twice as big and with a longer life span were found to be egl-4 mutants. The egl-4 gene was cloned and shown to encode cGMP dependent protein kinases. In egl-4 mutants, volumes of intestine, hypodermis, muscle, intestinal and muscle cells were increased but their cell numbers were not. egl-4 gene funetions in relation to TGF β and insulin pathways for the control of body size and life span, respectively. |
10.Key Words
(1)Nematode、(2)Body size、(3)Life span
(4)Axonal elongation、(5)Learning、(6)Muscle gene
(7)Embryonic lethality、(8)Expression vector、(9)Thermal sense