2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

�110 Andreas Ziegler A 704 / 14:45
The effect of saline and organic matrix proteins from Porcellio scaber sternal
deposits on CaCO3 precipitation under near physiological conditions
Authors: Andreas Ziegler 1 , Sigrid Hennig 1 , Helge-Otto Fabritius 1 , Sabine Hild 1
Affiliation: 1 Central Facility for Electron Microscopy, University of Ulm, Germany
The terrestrial isopod Porcellio scaber stores CaCO3 within a confined ecdysial space
in the first four anterior sternites. The deposits consist mainly of amorphous calcium
carbonate (ACC), little amorphous calcium phosphate and an organic matrix. In order
to study precipitation of CaCO3 under near physiological conditions we measured the
cationic composition and the pH in the ecdysial fluid of the sternites using ion
selective microelectrodes and isolated the soluble protein fraction of the organic
matrix from the deposits. We designed a near physiological, but phosphate-free
saline and developed a method that allows precipitation of CaCO3 in volumes as
small as 20 µl. Structure, mineral phase and composition of the precipitates were
analysed by FE-SEM, Raman spectroscopy and EDX. Within near physiological saline
the total soluble protein fraction leads to precipitation of ACC. Agglomerations of
ACC granules and the dried soluble fraction of the organic matrix are virtually devoid
of organic phosphates. The agglomerations mimic several aspects in the architecture
of native sternal deposits and were stable for at least one month. The saline alone
has no effect on the crystal phase but leads to changes in calcite crystal morphology
due to the effects of Mg2+. BSA that was used as a control protein has virtually no
effect on the mineral phase, but in the presence of Mg2+, severe effects on the
surface structure of calcite crystals, suggesting a combined effect of BSA and Mg2+
on crystal growth.
�111 Saskia Lieberei A 704 / 15:00
Identification of carriers for the uptake of plant secondary substances in
Longitarsus jacobaeae (Coleoptera, Chrysomelidae)
Authors: Saskia Lieberei 1 , Susanne Dobler 1
Affiliation: 1 Biozentrum Grindel, Molekulare Evolutionsbiologie, Universität Hamburg
Several host plant adapted herbivorous insects are able to use toxic plant secondary
compounds for their own chemical defense and protection. These insects sequester
the plant defense compounds and store them in their own tissue. Accumulation of
these substances guarantees a powerful deterrent against their predators.
Several species of leaf beetles (Chrysomelidae) use this defense strategy. The species
Longitarsus jacobaeae e.g. accumulates the pyrrolizidin alkaloid (PA) senecionin. In
non-adapted organisms the non toxic N-oxides are transferred to the highly toxic
tertiary PAs under the mildly reducing conditions in the intestine. L. jacobaeae, in
contrast, takes up the N-oxide from the plant tissue and transfers it unchanged into
the hemolymph (Narberhaus et al. 2004). Obviously this transport of the labile Noxide
is realized by highly efficient carriers. We assume that carriers of the family
organic anion transporting polypeptides (Oatps) are highly likely candidates for this
process. In addition, it could be proven by PCR, that there is a tissue specific
distribution of Oatps, especially in the intestine. In order to further investigate our
hypothesis, Oatp-genes have been isolated from cDNA of L. jacobaeae and have been
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