Genome of the fresh water polyp Hydra sequenced
The fresh water polyp Hydra is a member of the 600 million year old phylum Cnidaria, which includes simple multicellular animals at the base of animal evolution. To assembly and annotate the genome, the scientists sequenced 1,2 billion base pairs of DNA with the help of two sequencing centers in the USA and then compared the sequence to the genomes of higher animals and humans. The research was supported by the German Science Foundation (DFG), the National Science Foundation (NSF) and the National Human Genome Research Institute (NHGRI) in the USA, the National Institute of Genetics (NIG) in Japan and the Austrian Science Foundation (FWF).
The results show the striking degree to which genetic information is conserved between a simple animal form and higher animals and humans. Like other animal genomes, the genome of Hydra has ca 20,000 genes. All the essential signaling pathways controlling the formation of epithelia, muscle tissue, stem cells, nerve cells and the innate immune system are present in the Hydra genome. Thus, the “molecular tool kit” leading to the evolution of higher animals and humans was already present at the beginning of multicellular life. The question of how this toolkit was used to establish the basic animal Bauplan and how this evolved in higher animals can now be answered.
Hydra was first described in 1702 by Antoni van Leeuwenhoek. Forty years later in 1744 Abraham Trembley published his remarkable experiments on the polyp Hydra, demonstrating the regeneration of animal parts, tissue transplantation and the asexual formation of daughter animals by budding. Since then, Hydra has been an important model organism for the study of regeneration and animal development. These investigations have led to discoveries of fundamental importance in experimental biology. The unlimited capacity for regeneration and the apparent absence of aging in Hydra, together with the now sequenced genome, continue to make Hydra an important model organism with the potential for new advances in stem cell biology and biomedical research.
Research teams in the laboratories of Prof. Charles David (LMU), Prof. Thomas Bosch (Kiel), Prof. Thomas Holstein (Heidelberg), Prof. Bert Hobmayer (Innsbruck), Prof. Uli Technau (Vienna) and Prof. Thomas Rattei (Vienna) made major contributions to the Hydra genome project.
"The Dynamic Genome of Hydra"
Jarrod A. Chapman, Ewen F. Kirkness, Oleg Simakov et al.
Nature online, 14 March 2010