Membrane microdomain formation is crucial in epiboly during gastrulation of medaka.
Membrane microdomain (microdomain) was isolated from early gastrula embryos. The isolated microdomain was characterized by enrichment of cholesterol and sphingomyelin, and by the presence of huge glycoproteins containing Lewis X structure. Importance of the microdomain in the progress of epiboly was assessed using methyl beta-cyclodextrin (MBCD) and C2-ceramide that disrupt microdomains through different mechanisms. Both reagents efficiently disrupted the microdomain structure and concomitantly impaired epiboly. Interestingly, when embryos pretreated with MBCD, a cholesterol-binding molecule, were exogenously supplemented with cholesterol, the embryos underwent not only reconstitution of the microdomain, but also complete restoration to the normal epiboly. Thus, normal or impaired development is reversibly controlled by the cholesterol-dependent formation or disruption of microdomains. The most typical phenotype of the microdomain-disrupted embryos is detachment of cells from the blastoderm, suggesting that a major contribution of microdomains to epiboly is cell adhesion of blastodermal cells.
Adachi
Tomoko
T
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
Sato
Chihiro
C
Kitajima
Ken
K
D000818:Animals; D001756:Blastoderm / Q000187:drug effects; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D005775:Gastrula / Q000187:drug effects / Q000378:metabolism*; D016256:Lewis X Antigen / Q000378:metabolism; D008055:Lipids / Q000737:chemistry; D021962:Membrane Microdomains / Q000737:chemistry* / Q000378:metabolism; D009990:Oryzias; D013110:Sphingosine / Q000031:analogs & derivatives / Q000737:chemistry; D013696:Temperature; D047392:beta-Cyclodextrins / Q000737:chemistry
D003902:Detergents; D016256:Lewis X Antigen; D008055:Lipids; C064769:N-acetylsphingosine; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002784:Cholesterol; D013110:Sphingosine