2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

(ii) the characterization of candidate lunar light sensors and their spectral sensitivity
(iii) the analysis of circadian clock components and their regulation under light
regimes that mimic different phases of the lunar cycle.
Our results suggest that lunar and circadian clocks are molecularly connected, and
provide new molecular entry points into the study of light-dependent marine
rhythms.
Invited speaker 2: Chair – Nico Prpic Schäper A 702 / 12:00
Benjamin Altenhein (Mainz)
Glial cell development in Drosophila: from cell fate specification to function
Author: Benjamin Altenhein 1
Affiliation: 1 Institut für Genetik, Universität Mainz
The nervous system of vertebrates and invertebrates comprises two major cell types,
neurons and glial cells. In Drosophila both cell types are generated by common
precursors or neural stem cells, the so called neuroblasts (NB). At the end of
gastrulation, these NB delaminate from the neuroectoderm into the embryo and
divide in a stem cell mode, thereby generating stereotyped cell clones of neurons
and/or glial cells. The binary choice between neuron and glia as well as further cell
fate specification in the developing nervous system is achieved by a combination of
positional information of the NB already in the neuroectoderm, temporal
specification within each NB lineage, and asymmetric distribution of determinants
during mitosis. Recent work in our lab revealed that nearly all glial cells within an
abdominal hemineuromere of the fly embryo represent individual cell identities as
reflected by a combinatorial code of marker gene expression and a stereotyped
positioning, the latter being a consequence of an individual migratiory behaviour of
these cells. Specification eventually results in functional diversification of the entire
glial population which again is reflected by differential gene expression accompanied
by morphological and physiological changes. The genetic and molecular program
underlying such glial cell specification however, is poorly understood. I will present
our recent approaches towards a better understanding of these specification steps,
though not yet fully unravelled. Furthermore, I will show that differential expression
of particular genes already early in glial development regulates glial function in the
larval and adult nervous system. These functions influence cell-cell connections
between glia and neurons, neurons and muscles, and among neurons or glia
themselves. Loss of function of these glial genes results in structural and/or
physiological deficits of the flies, which will be demonstrated by different
approaches. After all, a clear understanding of glial cell specification and the resulting
functional diversification of these cells will help to better understand the
functionality of the nervous system in its entity (not only in Drosophila).
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