Cell lineage studies with a 4D-microscopy system
Cells are an important unit of the developing embryo. An embryo starts usually as a one cell stage and after divisions of this one cell the embryo establishes a cell lineage which gives rise to the adult organism and its germ layers, tissues and organs. Some animals have a extremely stereotyped cell division pattern and the future fate of the blastomeres of early developmental stages are established. Other embryos show a "regulative" cell division pattern, in which - after experimental manipulations - cells can adopt the fate of the destroyed blastomeres.
The investigations of the cell lineage of diverse embryos has a long tradition and one of the famous keyplayers were Edmund B. Wilson and Edwin G. Conklin at the end of the 18th century, which described cell lineages of mainly spiralian embryos. In the last 20 years, with the development of the method of injecting single blastomeres with cell tracing dyes, which allow the detection of their final fate a renewal of the interest in cell lineage studies has begun. The new hypothesis about the phylogenetic relationships between metazoan taxa initiated by the use of sequenze comparisons of molecules and the interest in comparative developmental biology ("evo-devo") re-encourages many investigators to look at the development also of minor groups.
My research focusses on the comparative studies of cell lineages with the use of a new technique, the 4D-microscopy (3D-timelapse). The advantage of this method over the use of cell tracing dyes is that all cell events are recorded, including the whole cell divisions, programmed cell deaths (apoptoses) and cell migrations. Thus the whole embryogensis is documented and allows a very detailed analysis with the commercial available software SIMI°BioCell.
I investigated different animals rerarding their cell lineage, as the eutardigrade Thulinia stephaniae, the rotifers Lecane dicipiens and Philodina roseola, the gastrotrich Lepidodermella squamata. Partly investigated cell lineages were reconstructed from the polychaete annelid Trilobodrilus axi and an acoel flatworm Mecynostomum sp.
These cell lineages not only give insights into the development of these representatives of their taxa, they also deliver an important basis for further studies on molecular levels, as the description of the cell lineage of Caenorhabditis elegans by Sulston and coworkers was for establishing this nematode species as a nematode representative for further studies of its development.