|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|
|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|
|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.
(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