This work aims at describing episcopic 3D imaging methods and at discussing how
these methods can contribute to researching the genetic mechanisms driving embryogenesis
and tissue remodelling, and the genesis of pathologies. Several episcopic 3D imaging methods
exist. The most advanced are capable of generating high-resolution volume data (voxel sizes
from 0.5x0.5x1μm3 upwards) of small to large embryos of model organisms and tissue
samples. Beside anatomy and tissue architecture, gene expression and gene product patterns
can be three dimensionally analyzed in their precise anatomical and histological context with
the aid of whole mount in situ hybridization or whole mount immunohistochemical staining
techniques. Episcopic 3D imaging techniques were and are employed for analyzing the precise
morphological phenotype of experimentally malformed, randomly produced, or genetically
engineered embryos of biomedical model organisms. It has been shown that episcopic 3D
imaging also fits for describing the spatial distribution of genes and gene products during
embryogenesis, and that it can be used for analyzing tissue samples of adult model animals and
humans. The latter offers the possibility to use episcopic 3D imaging techniques for
researching the causality and treatment of pathologies or for staging cancer. Such applications,
however, are not yet routine and currently only preliminary results are available. We conclude
that, although episcopic 3D imaging is in its very beginnings, it represents an upcoming
methodology, which in short terms will become an indispensable tool for researching the
genetic regulation of embryo development as well as the genesis of malformations and
diseases.
Keywords: 3D modelling, episcopic microscopy, imaging, embryo, development,
gene expression.
