2005 Fiscal Year Final Research Report Summary
Mechanisms of gastrulation in newt embryo
| Project/Area Number |
16590149
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Kitasato University |
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Principal Investigator |
OBATA Shuichi Kitasato University, College of Liberal Arts and Sciences, Assis.Prof., 一般教育部, 講師 (10204273)
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| Co-Investigator(Kenkyū-buntansha) |
ONO Michio Yokohama City University, Medicine, Assis.Prof., 医学部, 助手 (50264601)
SAWADA Hajime Yokohama City University, Medicine, Prof., 大学院・医学研究科, 教授 (90101112)
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| Project Period (FY) |
2004 – 2005
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| Keywords | early development / morphogenesis / gastrulation / cell motility / cytoskeleton |
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| Research Abstract |
Gastrulation is one of important steps for morphogenesis in most species of multicellular animal embryos. The gastrulation is a complex phenomenon combined with several cellular events, for example, cell movements, cell shape changes, cell-cell and cell-matrix adhesions. Especially, the cell movements and cell shape changes are important to form an archenteron (primitive gut) and mesoderm layer. Holtfreter reported two types of unique cell movements, creeping movement of vermiform cells and circus movement characteristic of Amoeba, in isolated embryonic cells from amphibian gastrulae, and suggested that these cell movements were important in gastrulation of amphibian embryos. The creeping movement was suggested to play roles in drawing blastopore into the embryo. However, little is known about mechanisms of these cell movements and their roles playing in gastrulation yet. We investigated mechanisms of creeping movement to understand the physiological roles of this movement in gastrulat
… More
ion.
In early gastrula embryo, presumptive mesodermal cells invaginating into the embryo and a part of presumptive endodermal cells transformed into sausage-like shape. They elongated toward the direction of invagination of the archenteron. The elongated cells, called vermiform cells, were also observed both in the dissociated mesodermal and endodermal cells. A hyaline pseudopodium was formed at protruded end in the vermifom cell, and a small knob at the opposite end. We analyzed the creeping movement in the vermiform cells by time-lapse microscopy. The cells moved with the hyaline pseudopodium at the head. Several contracted sites were observed at the surface of the cell, simultaneously. The contraction waves at the cell surface moved backward, from the pseudopodium side to the knob side. Yolk granules and pigment granules also changed their positions inside the cells. By treatment of cytochalasin D (inhibitor for actin polymerization), the sausage-like shape of the vermiform cell quickly changed into round one. The elongation of the cells, contraction waves, and streaming of yolk granules and pigment granules were also completely inhibited by this treatment. Nocodazole (inhibitor for microtubule polymerization), however, did not affect them. Less
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Research Products
(8 results)
