Dynamic patterns of apoptosis in the developing chicken heart

Authors

  • Katherine S. Schaefer,

    1. Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
    Current affiliation:
    1. Randolph-Macon Woman's College, Department of Biology, 2500 Rivermont Avenue, Lynchburg, VA 24503
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  • Yong Qiu Doughman,

    1. Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
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  • Steven A. Fisher,

    1. Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
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  • Michiko Watanabe

    Corresponding author
    1. Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
    • Department of Pediatrics, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland OH 44106-6011
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Abstract

The outflow tract (OFT) is abnormal in many congenital heart defects. One critical mechanism for morphogenesis of this complex structure is apoptosis. Chicken embryos (stages 19–38; ED4–10) stained with a fluorescent supravital lysosomal dye (LysoTracker Red; LTR) revealed the three-dimensional relationship between structural changes and apoptosis. The LTR staining peaked in the OFT myocardium at stages 27–32, consistent with our previous analyses using other apoptosis assays. While LTR stained under both the pulmonary artery and the aorta, it was most prevalent in the subaortic myocardium before its elimination. Furthermore, LTR staining was most abundant in the myocardium under intensely cytokeratin-positive, thick epicardium. These data support the hypothesis that temporally and spatially restricted apoptosis in the OFT myocardium allows the aorta and pulmonary artery to dock at the appropriate angle and level with the proper ventricle. These data also support a relationship between the differentiating epicardium and cardiomyocyte apoptosis. Developmental Dynamics 229:489–499, 2004. © 2004 Wiley-Liss, Inc.

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