Abstracts - Deutsche Zoologische Gesellschaft

Developmental Biology Posters 119P DB.1 - ENDevelopmental insights to the arthropod head problemGregor Bucher, Nico PosnienBlumenbach Institut für Zoologie und Anthropologie, Georg August Universität GöttingenThe insect head is a complex structure composed of several segments fused to a probably non-segmentalanterior tissue, the acron. However, there is no agreement on the number of segments andthe extent of non-segmental tissue. It also remains debated whether the labrum (the so called “upperlip”) is a derived appendage originating from a segment or whether it has evolved as part of theacron. We use the red flour beetle Tribolium castaneum as model system for the genetics and evolutionof head development. We test the hypothesis of a labral parasegment boundary by investigatingexpression and function of the segment polarity genes wingless, engrailed and hedgehog. We find noevidence for a labral parasegment boundary and conclude that six parasegment boundaries are foundin the insect head anlagen. As corollary, we propose that the acron comprises a significant part ofthe tissue anterior to the ocular parasegment boundary. Similar expression and function of genes inthe outgrowth of labrum and trunk appendage argue for homology of these structures. However, wealso find strong evidence that the labrum arises as part of the non-segmental acron and that the positionof its anlagen is deeply different from trunk appendages which contradicts a segmental origin.We reconcile these antitheses by suggesting that the network responsible for appendage outgrowthevolved in one of these structures and became re-deployed to form the other.P DB.2 - ENAnalysis of ageing-associated genes and telomere length in the short-lived fishNothobranchius furzeri – a new model organism for age researchNils HartmannMolekulare Genetik, Leibniz-Institut für Altersforschung (FLI), JenaAge research in vertebrates is usually constrained by the longevity of available models. The annualfish Nothobranchius furzeri lives in temporary pools of Southern Africa, which are only present duringthe rainy season, and exhibits an exceptionally short life span of only 3 – 6 months. This shortlife span is considered to depend on the amount of rain fall and the duration of the rainy season.We analyzed several ageing-associated genes that code for proteins that are involved in cell-cycleregulation, energy metabolism, ROS detoxification and telomere maintenance. N. furzeri-specificsequences were obtained by homology cloning and RACE. Identity values of the derived amino acidsequences between N. furzeri and the teleost fish Takifugu rubripes range from 55% to 93%, whereasidentity values between N. furzeri and human range from 34% to 87%. Study of gene expressionrevealed that most genes analyzed are not changed when comparing young (5-weeks-old) and old(21-weeks-old) tissues. However, expression of the p21, Tert, Sod2, and Cat gene is significantlyaltered during ageing. Moreover, we determined the telomere length of young (5-weeks-old) and old(21-weeks-old) fish. Despite high individual differences, a significant shortening of mean telomerelength was observed in aged tissues. In future, we want to establish transgenesis in N. furzeri to manipulategene expression and determine the effect of this manipulation on life span. We also want toanalyze the effect of different factors such as pharmacological substances on life span.