Hydra – Emerging Model System

Phylogeny

Abraham Trembley (1744) Mémoires pour servir à l'histoire d'un genre de polypes d'eau douce, Gebr. Verbeek, Leiden

History

Scale bar = 2.5 mm

Phylum : CnidariaClass : HydrozoaFamily : HydridaeGenus : Hydra

Hydra vulgaris Ind-Pune

General Morphology of Hydra

Stem Cells

Types of Nematocysts

Scale bar = 5μm

Asexual Reproduction by Budding

Scale bar = 0.1mm

Regeneration Capacity of Hydra

Longitudinal cut

Trisection

Traverse cut

Tissue Dynamics

Genome

2n=30Genome Size ~1.3 G bpGenome Assemblies –H.magnipapillata,

H.vulgaris Ind-Pune

(Adapted from Anokhin et.al., 2010)

Phylogeny(At the base of metazoan phyla)

Evolutionary transition(body axis, germ layers, gonads, cell types)

Pattern formation (peculiar tissue dynamics make hydra a perpetual embryo)

Regeneration, stem cells

What we can learn from Hydra