©2008 Bentham Science Publishers Ltd.
Episcopic 3D Imaging Methods: Tools for Researching Gene Function
Wolfgang J. Weninger
and Stefan H. Geyer
IMG, Centre for Anatomy and Cell Biology, Medical University of Vienna, Waehringer Str. 13, A-1090 Vienna, Austria
This work aims at describing episcopic 3D imaging methods and at discussing how these methods can contrib-
ute 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 0.5x0.5x1
m upwards) of small to large embryos of model organisms and tissue samples. Beside anat-
omy and tissue architecture, gene expression and gene product patterns can be three dimensionally analyzed in their pre-
cise anatomical and histological context with the aid of whole mount
hybridization or whole mount immunohisto-
chemical staining techniques. Episcopic 3D imaging techniques were and are employed for analyzing the precise morpho-
logical 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 hu-
mans. 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 meth-
odology, which in short terms will become an indispensable tool for researching the genetic regulation of embryo devel-
opment as well as the genesis of malformations and diseases.
Received on: March 11, 2008 - Revised on: April 14, 2008 - Accepted on: April 17, 2008
3D modelling, episcopic microscopy, imaging, embryo, development, gene expression.
Challenging hereditary diseases and pathologies requires
profound knowledge of the genetic and epigenetic pathways
regulating their genesis. Therefore modern biomedicine de-
veloped a number of different approaches for researching the
role and function of genes and gene products in normal and
diseased embryos, organs, and tissues. The following study
shall provide a very brief overview of techniques capable of
researching gene function. It will then focus on imaging
methods, which can quickly generate correctly registered
digital image stacks, captured from the block surfaces of
sequentially cut, histological processed, and embedded
specimens (three dimensional (3D) episcopic imaging meth-
ods). These methods will be described in more detail and
their value for researching gene function will be discussed.