Gene-expression profiling during embryogenesis of Zebrafish under microgravity conditions
- Paper number
IAC-06-A1.4.06
- Author
Mr. Bernd Willems, University of Cologne, Germany
- Coauthor
Dr. Martin Gajewski, University of Cologne, Germany
- Year
2006
- Abstract
In the last years zebrafish (Danio rerio) has become a very important model organism for studies concerning changes induced in a vertebrate exposed to gravitational stress and thus raising the complexity of the research object from cell culture to a whole animal. Recently, scientists focused on the embryogenesis of this model organism in order to establish a better understanding of reproduction of higher animals outside of the earth. The advantages of this model-organism are obvious, it shows a very high homology in nucleotide sequence of many genes among vertebrates. More advantages of this specimen are its short generation time, easy maintenance, high quantities of offspring, transparent embryos and applicability to established methods in molecular biology. Since zebrafish embryos developed in space were just analysed on a morphological level and little is known about alterations in gene expression caused by gravitational stress, we conducted on a molecular level an appropriate gene expression profiling experiment. This was realized by using Microarray (gene-chip) technology, one of the most sophisticated methods modern molecular biology has to offer to characterize the whole transcriptome under different conditions. This was the first time that the global gene-expression pattern of an entire vertebrate organism exposed to weightlessness was acquired. Zebrafish embryos were exposed to short phases of microgravity throughout a parabolic flight. Controls also flew and were kept in a respective 1xg-centrifuge which was automatically activated during µg-phases. This ensured equal gravitational conditions along the flight except during the µg-phases. For analysis mRNA of all embryos was isolated directly after landing and later hybridised to Microarray-chips from a 16k-oligo-library. After analysing data from 7 chips and comparing them to an equal amount of WT:WT-chips to eliminate false positives 57 candidate genes were identified which are thought to be differentially regulated under weightlessness conditions. According to the annotated function of these candidates they were classified into different groups to give an overall view about the different types of affected genes. A vast amount of genes ( 30%) belong to the organisation and maintenance of neuronal structures such as brain and sensory organs. This finding strongly contributes to morphological experiments which already suggested changes in the development of neuronal organs. The other genes were grouped into the following fractions: unknown function ( 34%) response to stress ( 4%), cytoskeleton and muscle( 7%), development( 12%), housekeeping ( 7%), transport( 2%) and signal transduction( 4%). After all parabolic flight appears to be an applicable tool for microgravity-related gene-expression experiments.
- Abstract document
- Manuscript document
IAC-06-A1.4.06.pdf (🔒 authorized access only).
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