title: Studying developmental variation with Geometric Morphometric Image Analysis (GMIA).
abstract: The ways in which embryo development can vary across individuals of a population determine how genetic variation translates into adult phenotypic variation. The study of developmental variation has been hampered by the lack of quantitative methods for the joint analysis of embryo shape and the spatial distribution of cellular activity within the developing embryo geometry. By drawing from the strength of geometric morphometrics and pixel/voxel-based image analysis, we present a new approach for the biometric analysis of two-dimensional and three-dimensional embryonic images. Well-differentiated structures are described in terms of their shape, whereas structures with diffuse boundaries, such as emerging cell condensations or molecular gradients, are described as spatial patterns of intensities. We applied this approach to microscopic images of the tail fins of larval and juvenile rainbow trout. Inter-individual variation of shape and cell density was found highly spatially structured across the tail fin and temporally dynamic throughout the investigated period.
authors.affiliation: Department of Theoretical Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, A-1090, Vienna, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Mayer
authors.affiliation: Department of Theoretical Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, A-1090, Vienna, Austria.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Metscher
authors.affiliation: Department of Theoretical Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, A-1090, Vienna, Austria.
authors.forename: Gerd B
authors.initials: GB
authors.lastname: Müller
authors.affiliation: Department of Theoretical Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, A-1090, Vienna, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Mitteroecker
mesh_terms: D000818:Animals; D001837:Body Weights and Measures / Q000379:methods*; D047108:Embryonic Development / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D017686:Oncorhynchus mykiss / Q000196:embryology*; D025341:Principal Component Analysis; D062206:Spatial Analysis; D013623:Tail / Q000196:embryology