Multicellular rosette formation during cell ingression in the avian primitive streak

Authors

  • Laura J. Wagstaff,

    1. Cell and Developmental Biology, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
    2. Biomedical Research Center, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
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  • Gemma Bellett,

    1. Biomedical Research Center, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
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  • Mette M. Mogensen,

    1. Biomedical Research Center, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
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  • Andrea Münsterberg

    Corresponding author
    1. Cell and Developmental Biology, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
    • School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
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Abstract

Cell movements are a fundamental feature during the development of multi-cellular organisms. In amniote gastrulation, cells ingress through the primitive streak, which identifies the anterior-posterior axis of the embryo. We investigated the cytoskeletal architecture during these morphogenetic processes and characterized microtubule organisation in whole chick embryos. This revealed the distribution of cells with polarized and radial microtubule (MT) arrays across different regions of the embryo. Cells in the epiblast usually displayed radial MT-arrays, while the majority of cells in the primitive streak had polarized MT-arrays. Within the primitive streak, many cells organized into groups and were arranged in rosette-like structures with a distinct centre characterized by an accumulation of actin. Extended confocal microscopy and three-dimensional image reconstruction identified tips of polarized cells that were protruding from the plane of rosettes, usually from the centre. We propose that organization into higher order structures facilitates cell ingression during gastrulation. Developmental Dynamics 237:91–96, 2008. © 2007 Wiley-Liss, Inc.

Ancillary