Summary of Research Project Results under JSPS FY2001
"Research for the Future Program"

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

7.Project Leader
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