Dr Angelika Stollewerk
Reader in Evolutionary Developmental Biology
- Room: 4.18, Fogg Building
- Telephone: +44 (0)20 7882 3054
- Email: a.stollewerk ("at" sign) qmul.ac.uk
Research interests:
Research website: http://stollewerk.co.uk
I am interested in the question of how neural development has been modified during evolution to give rise to the high diversity of adult nervous systems in arthropods (insects, crustaceans, chelicerates, myriapods). Evolutionary modifications of neural networks can in principle be achieved during different processes of neural development: (1) by changes in the generation of neural precursors (early neurogenesis) (2) by changes in the establishment of neural precursor identity, (3) by changes in the proliferation of individual progenitor lineages, (4) by modifications of axonal pathfinding, i.e. changes in the expression of guidance molecules or changes in the intrinsic properties of pioneer neurons.
Until recently neural developmental processes have only been compared in insects, malacostracan crustaceans and a single myriapod. Our analyses of early neurogenesis in several representatives of chelicerates (spiders and scorpions) and myriapods (millipedes and centipedes) have revealed that the genetic network involved in recruitment and specification of neural precursors is conserved in these arthropod groups. However, the expression pattern and function of these genes is adapted to the distinct morphology of neural precursor formation in each group. We observed several characters in chelicerates and myriapods that cannot be found in equivalent form in insects and crustaceans. (1) Groups of neural precursors invaginate from the ventral neuroectoderm of chelicerates and myriapods in a strikingly similar pattern, while single stem-cell like neuroblasts are specified in insects and malacostracan crustaceans. (2) In contrast to insects and crustaceans, neural precursors do not divide in a stem cell-like mode in chelicerates and myriapods. (3) The central region of the ventral neuroectoderm in chelicerates and myriapods generates exclusively neural cells while in insects and crustaceans both neural and epidermal cells arise from the ventral neurogenic region. It is possible that these characters are shared derived characters (synapomorphies) of myriapods and chelicerates, providing the first morphological support for a clade uniting these two groups. However, they could also represent ancestral characters (symplesiomorphies) retained in myriapods and chelicerates and lost in the more derived insects and crustaceans.
We are analysing neurogenesis in all four arthropod groups and outgroups to the euarthropods (onychophoran and tardigrades) - from the formation of neural precursors up to the establishment of neuronal networks - using morphological and molecular tools in order to understand (1) in what way the developmental mechanisms have been modified in the individual arthropod groups and (2) to distinguish derived characters of neurogenesis that can be used for resolving euarthropod relationships.
Research group:
Postgraduate supervision:
Biffar, Lucia; l.biffar ("at" sign) qmul.ac.uk;
Klann, Marleen; m.klann ("at" sign) qmul.ac.uk;