D. Duboule and A. Wilkins, The evolution of `bricolage', Trends in Genetics, vol.14, issue.2, pp.54-59, 1998.
DOI : 10.1016/S0168-9525(97)01358-9

A. Pires-dasilva and R. Sommer, The evolution of signalling pathways in animal development, Nature Reviews Genetics, vol.2, issue.1, pp.39-49, 2003.
DOI : 10.1038/nrg977

S. Carroll, Evo-Devo and an Expanding Evolutionary Synthesis: A Genetic Theory of Morphological Evolution, Cell, vol.134, issue.1, pp.25-36, 2008.
DOI : 10.1016/j.cell.2008.06.030

U. Technau, S. Rudd, P. Maxwell, P. Gordon, and M. Saina, Maintenance of ancestral complexity and non-metazoan genes in two basal cnidarians, Trends in Genetics, vol.21, issue.12, pp.633-639, 2005.
DOI : 10.1016/j.tig.2005.09.007

D. Miller, E. Ball, and U. Technau, Cnidarians and ancestral genetic complexity in the animal kingdom, Trends in Genetics, vol.21, issue.10, pp.536-539, 2005.
DOI : 10.1016/j.tig.2005.08.002

B. Degnan, M. Vervoort, C. Larroux, and G. Richards, Early evolution of metazoan transcription factors, Current Opinion in Genetics & Development, vol.19, issue.6, pp.591-599, 2009.
DOI : 10.1016/j.gde.2009.09.008
URL : https://hal.archives-ouvertes.fr/hal-00486314

N. Putnam, M. Srivastava, U. Hellsten, B. Dirks, and J. Chapman, Sea Anemone Genome Reveals Ancestral Eumetazoan Gene Repertoire and Genomic Organization, Science, vol.317, issue.5834, pp.86-94, 2007.
DOI : 10.1126/science.1139158

J. Chapman, E. Kirkness, O. Simakov, S. Hampson, and T. Mitros, The dynamic genome of Hydra, Nature, vol.103, issue.7288, pp.592-596, 2010.
DOI : 10.1038/nature08830

C. Larroux, G. Luke, P. Koopman, D. Rokhsar, and S. Shimeld, Genesis and Expansion of Metazoan Transcription Factor Gene Classes, Molecular Biology and Evolution, vol.25, issue.5, pp.980-996, 2008.
DOI : 10.1093/molbev/msn047

D. Hoshiyama, H. Suga, N. Iwabe, and M. Koyanagi, Sponge Pax cDNA Related to Pax-2/5/8 and Ancient Gene Duplications in the Pax Family, Journal of Molecular Evolution, vol.47, issue.6, pp.640-648, 1998.
DOI : 10.1007/PL00006421

H. Bielen, S. Oberleitner, S. Marcellini, L. Gee, and P. Lemaire, Divergent functions of two ancient Hydra Brachyury paralogues suggest specific roles for their C-terminal domains in tissue fate induction, Development, vol.134, issue.23, pp.4187-4197, 2007.
DOI : 10.1242/dev.010173
URL : https://hal.archives-ouvertes.fr/hal-00303134

C. Magie, K. Pang, and M. Martindale, Genomic inventory and expression of Sox and Fox genes in the cnidarian Nematostella vectensis, Development Genes and Evolution, vol.273, issue.12, pp.618-630, 2005.
DOI : 10.1007/s00427-005-0022-y

J. Ryan, P. Burton, M. Mazza, G. Kwong, and J. Mullikin, The cnidarian-bilaterian ancestor possessed at least 56 homeoboxes: evidence from the starlet sea anemone, Nematostella vectensis, Genome Biol, vol.7, 2006.

S. Forêt, B. Knack, E. Houliston, T. Momose, and M. Manuel, New tricks with old genes: the genetic bases of novel cnidarian traits, Trends in Genetics, vol.26, issue.4, pp.154-158, 2010.
DOI : 10.1016/j.tig.2010.01.003

S. Chevalier, A. Martin, L. Leclère, A. Amiel, and E. Houliston, Polarised expression of FoxB and FoxQ2 genes during development of the hydrozoan Clytia hemisphaerica, Development Genes and Evolution, vol.213, issue.11, pp.709-720, 2006.
DOI : 10.1007/s00427-006-0103-6

R. Chiori, M. Jager, E. Denker, P. Wincker, D. Silva et al., Are Hox Genes Ancestrally Involved in Axial Patterning? Evidence from the Hydrozoan Clytia hemisphaerica (Cnidaria), PLoS ONE, vol.52, issue.1, 2009.
DOI : 10.1371/journal.pone.0004231.s003
URL : https://hal.archives-ouvertes.fr/hal-00498060

M. Jager, E. Quéinnec, L. Guyader, H. Manuel, and M. , Multiple Sox genes are expressed in stem cells or in differentiating neuro-sensory cells in the hydrozoan Clytia hemisphaerica, EvoDevo, vol.2, issue.1, pp.12-22, 2011.
DOI : 10.1016/j.neulet.2004.01.026

K. Khalturin, G. Hemmrich, S. Fraune, A. R. Bosch, and T. , More than just orphans: are taxonomically-restricted genes important in evolution?, Trends in Genetics, vol.25, issue.9, pp.404-413, 2009.
DOI : 10.1016/j.tig.2009.07.006

T. Domazet-lo?o and D. Tautz, An Evolutionary Analysis of Orphan Genes in Drosophila, Genome Research, vol.13, issue.10, 2003.
DOI : 10.1101/gr.1311003

D. Tautz and T. Domazet-lo?o, The evolutionary origin of orphan genes, Nature Reviews Genetics, vol.22, issue.10, pp.692-702, 2011.
DOI : 10.1038/nrg3053

R. Neme and D. Tautz, Phylogenetic patterns of emergence of new genes support a model of frequent de novo evolution, BMC Genomics, vol.14, issue.1, pp.10-1186, 2013.
DOI : 10.1093/nar/25.17.3389

R. Steele, The Hydra genome: insights, puzzles and opportunities for Developmental Biologists, The International Journal of Developmental Biology, vol.56, issue.6-7-8, pp.535-542, 2012.
DOI : 10.1387/ijdb.113462rs

R. Steele, C. David, and U. Technau, A genomic view of 500 million years of cnidarian evolution, Trends in Genetics, vol.27, issue.1, pp.7-13, 2011.
DOI : 10.1016/j.tig.2010.10.002

J. Hwang, H. Ohyanagi, S. Hayakawa, N. Osato, and C. Nishimiya-fujisawa, The evolutionary emergence of cell type-specific genes inferred from the gene expression analysis of Hydra, Proceedings of the National Academy of Sciences, vol.104, issue.37, pp.14735-14740, 2007.
DOI : 10.1073/pnas.0703331104

G. Hemmrich, K. Khalturin, A. Boehm, M. Puchert, and F. Anton-erxleben, Molecular Signatures of the Three Stem Cell Lineages in Hydra and the Emergence of Stem Cell Function at the Base of Multicellularity, Molecular Biology and Evolution, vol.29, issue.11, pp.3267-3280, 2012.
DOI : 10.1093/molbev/mss134

S. Milde, G. Hemmrich, F. Anton-erxleben, K. Khalturin, and J. Wittlieb, Characterization of taxonomically restricted genes in a phylum-restricted cell type, Genome Biology, vol.10, issue.1, 2009.
DOI : 10.1007/s004410000240

A. Grens, H. Shimizu, S. Hoffmeister, H. Bode, and T. Fujisawa, The novel signal peptides, pedibin and Hym-346, lower positional value thereby enhancing foot formation in hydra, Development, vol.126, pp.517-524, 1999.

J. Lohmann, I. Endl, and T. Bosch, Silencing of Developmental Genes in Hydra, Developmental Biology, vol.214, issue.1, pp.211-214, 1999.
DOI : 10.1006/dbio.1999.9407

J. Lohmann and T. Bosch, The novel peptide HEADY specifies apical fate in a simple radially symmetric metazoan, Genes & Development, vol.14, issue.21, pp.2771-2777, 2000.
DOI : 10.1101/gad.830100

K. Khalturin, F. Anton-erxleben, S. Sassmann, J. Wittlieb, and G. Hemmrich, A Novel Gene Family Controls Species-Specific Morphological Traits in Hydra, PLoS Biology, vol.214, issue.11, 2008.
DOI : 10.1371/journal.pbio.0060278.st005

G. Genikhovich, U. Kürn, G. Hemmrich, and T. Bosch, Discovery of genes expressed in Hydra embryogenesis, Developmental Biology, vol.289, issue.2, pp.466-481, 2006.
DOI : 10.1016/j.ydbio.2005.10.028

E. Houliston, T. Momose, and M. Manuel, Clytia hemisphaerica: a jellyfish cousin joins the laboratory, Trends in Genetics, vol.26, issue.4, pp.159-167, 2010.
DOI : 10.1016/j.tig.2010.01.008
URL : https://hal.archives-ouvertes.fr/hal-00594651

C. David, Interstitial stem cells in Hydra: multipotency and decision-making, The International Journal of Developmental Biology, vol.56, issue.6-7-8, pp.489-497, 2012.
DOI : 10.1387/ijdb.113476cd

T. Bosch, F. Anton-erxleben, G. Hemmrich, and K. Khalturin, The Hydra polyp: Nothing but an active stem cell community, Development, Growth & Differentiation, vol.283, issue.15, pp.15-25, 2010.
DOI : 10.1111/j.1440-169X.2009.01143.x

V. Martin and W. Archer, Migration of interstitial cells and their derivatives in a hydrozoan planula, Developmental Biology, vol.116, issue.2, pp.486-496, 1986.
DOI : 10.1016/0012-1606(86)90149-1

V. Martin, Development of Nerve Cells in Hydrozoan Planulae: III. Some Interstitial Cells Traverse the Ganglionic Pathway in the Endoderm, The Biological Bulletin, vol.178, issue.1, pp.10-20, 1990.
DOI : 10.2307/1541532

C. Byrum, An Analysis of Hydrozoan Gastrulation by Unipolar Ingression, Developmental Biology, vol.240, issue.2, pp.627-640, 2001.
DOI : 10.1006/dbio.2001.0484

G. Freeman, The cleavage initiation site establishes the posterior pole of the hydrozoan embryo, Wilhelm Roux's Archives of Developmental Biology, vol.14, issue.2, pp.123-125, 1981.
DOI : 10.1007/BF00848406

T. Momose and E. Houliston, Two Oppositely Localised Frizzled RNAs as Axis Determinants in a Cnidarian Embryo, PLoS Biology, vol.20, issue.4, 2007.
DOI : 10.1371/journal.pbio.0050070.g008

T. Momose, R. Derelle, and E. Houliston, A maternally localised Wnt ligand required for axial patterning in the cnidarian Clytia hemisphaerica, Development, vol.135, issue.12, pp.2105-2113, 2008.
DOI : 10.1242/dev.021543

T. Momose, Y. Kraus, and E. Houliston, A conserved function for Strabismus in establishing planar cell polarity in the ciliated ectoderm during cnidarian larval development, Development, vol.139, issue.23, pp.4374-4382, 2012.
DOI : 10.1242/dev.084251

A. Kusserow, K. Pang, C. Sturm, M. Hrouda, and J. Lentfer, Unexpected complexity of the Wnt gene family in a sea anemone, Nature, vol.21, issue.7022, pp.156-160, 2005.
DOI : 10.1038/35056041

G. Plickert, V. Jacoby, U. Frank, W. Müller, and O. Mokady, Wnt signaling in hydroid development: Formation of the primary body axis in embryogenesis and its subsequent patterning, Developmental Biology, vol.298, issue.2, pp.368-378, 2006.
DOI : 10.1016/j.ydbio.2006.06.043

M. Adamska, C. Larroux, M. Adamski, K. Green, and E. Lovas, Structure and expression of conserved Wnt pathway components in the demosponge Amphimedon queenslandica, Evolution & Development, vol.275, issue.5, 2010.
DOI : 10.1111/j.1525-142X.2010.00435.x

M. Adamska, S. Degnan, K. Green, M. Adamski, and A. Craigie, Wnt and TGF-beta expression in the sponge Amphimedon queenslandica and the origin of metazoan embryonic patterning, PLoS ONE, vol.2, 2007.

P. Windsor and S. Leys, Wnt signaling and induction in the sponge aquiferous system: evidence for an ancient origin of the organizer, Evolution & Development, vol.14, issue.(, pp.484-493, 2010.
DOI : 10.1111/j.1525-142X.2010.00434.x

K. Pang, J. Ryan, . Nisc-comparative-sequencing-program, J. Mullikin, and A. Baxevanis, Genomic insights into Wnt signaling in an early diverging metazoan, the ctenophore Mnemiopsis leidyi, EvoDevo, vol.1, issue.1, pp.10-10, 2010.
DOI : 10.1186/2041-9139-1-10

C. Petersen and P. Reddien, Polarized notum Activation at Wounds Inhibits Wnt Function to Promote Planarian Head Regeneration, Science, vol.332, issue.6031, pp.852-855, 2011.
DOI : 10.1126/science.1202143

S. Schneider and B. Bowerman, Animal Development: An Ancient ??-Catenin Switch?, Current Biology, vol.23, issue.8, pp.313-315, 2013.
DOI : 10.1016/j.cub.2013.03.011
URL : http://doi.org/10.1016/j.cub.2013.03.011

L. Wang, Z. Feng, X. Wang, X. Wang, and X. Zhang, DEGseq: an R package for identifying differentially expressed genes from RNA-seq data, Bioinformatics, vol.26, issue.1, pp.136-138, 2010.
DOI : 10.1093/bioinformatics/btp612

D. Parlier, V. Moers, C. Van-campenhout, J. Preillon, and L. Leclère, The Xenopus doublesex-related gene Dmrt5 is required for olfactory placode neurogenesis, Developmental Biology, vol.373, issue.1, pp.39-52, 2013.
DOI : 10.1016/j.ydbio.2012.10.003

Y. Kawano and R. Kypta, Secreted antagonists of the Wnt signalling pathway, Journal of Cell Science, vol.116, issue.13, pp.2627-2634, 2003.
DOI : 10.1242/jcs.00623

J. Filmus, M. Capurro, and J. Rast, Glypicans, Genome Biology, vol.9, issue.5, 2008.
DOI : 10.1186/gb-2008-9-5-224

G. Dhoot, M. Gustafsson, A. X. Sun, W. Standiford, and D. , Regulation of Wnt Signaling and Embryo Patterning by an Extracellular Sulfatase, Science, vol.293, issue.5535, pp.1663-1666, 2001.
DOI : 10.1126/science.293.5535.1663

Z. Chi, J. Zhang, A. Tokunaga, M. Harraz, and S. Byrne, Botch Promotes Neurogenesis by Antagonizing Notch, Developmental Cell, vol.22, issue.4, pp.707-720, 2012.
DOI : 10.1016/j.devcel.2012.02.011

W. Jr, K. Zimmermann, G. Rousset, R. Scott, and M. , Vertebrate Proteins Related to Drosophila Naked Cuticle Bind Dishevelled and Antagonize Wnt Signaling, Dev Biol, vol.234, pp.93-106, 2001.

T. Van-raay, N. Fortino, B. Miller, H. Ma, and G. Lau, Naked1 Antagonizes Wnt Signaling by Preventing Nuclear Accumulation of ??-Catenin, PLoS ONE, vol.19, issue.4, 2011.
DOI : 10.1371/journal.pone.0018650.s002

J. Hsieh, L. Lee, L. Zhang, S. Wefer, and K. Brown, Mesd Encodes an LRP5/6 Chaperone Essential for Specification of Mouse Embryonic Polarity, Cell, vol.112, issue.3, pp.355-367, 2003.
DOI : 10.1016/S0092-8674(03)00045-X

C. Lin, W. Lu, L. Zhai, T. Bethea, and K. Berry, Mesd is a general inhibitor of different Wnt ligands in Wnt/LRP signaling and inhibits PC-3 tumor growth in vivo, FEBS Letters, vol.107, issue.19, pp.3120-3125, 2011.
DOI : 10.1016/j.febslet.2011.08.046

L. Leclère, M. Jager, C. Barreau, P. Chang, L. Guyader et al., Maternally localized germ plasm mRNAs and germ cell/stem cell formation in the cnidarian Clytia, Developmental Biology, vol.364, issue.2, pp.236-248, 2012.
DOI : 10.1016/j.ydbio.2012.01.018

G. Freeman, The role of polarity in the development of the hydrozoan planula larva, Wilhelm Roux's Archives of Developmental Biology, vol.1, issue.3, pp.168-184, 1981.
DOI : 10.1007/BF00867804

T. Momose and V. Schmid, Animal pole determinants define oral???aboral axis polarity and endodermal cell-fate in hydrozoan jellyfish Podocoryne carnea, Developmental Biology, vol.292, issue.2, pp.371-380, 2006.
DOI : 10.1016/j.ydbio.2006.01.012

S. Angers and R. Moon, Proximal events in Wnt signal transduction, Nature Reviews Molecular Cell Biology, vol.316, pp.468-477, 2009.
DOI : 10.1038/nrm2717

P. Lapébie, C. Borchiellini, and E. Houliston, Dissecting the PCP pathway: One or more pathways?, BioEssays, vol.8, issue.10, pp.759-768, 2011.
DOI : 10.1002/bies.201100023

Y. Huang and C. Niehrs, Polarized Wnt Signaling Regulates Ectodermal Cell Fate in Xenopus, Developmental Cell, vol.29, issue.2, pp.250-257, 2014.
DOI : 10.1016/j.devcel.2014.03.015

U. Technau, Brachyury, the blastopore and the evolution of the mesoderm, BioEssays, vol.13, issue.9, pp.788-794, 2001.
DOI : 10.1002/bies.1114

A. Yamada, M. Martindale, A. Fukui, and S. Tochinai, Highly conserved functions of the Brachyury gene on morphogenetic movements: Insight from the early-diverging phylum Ctenophora, Developmental Biology, vol.339, issue.1, pp.212-222, 2010.
DOI : 10.1016/j.ydbio.2009.12.019

C. Sinigaglia, H. Busengdal, L. Leclère, U. Technau, and F. Rentzsch, The Bilaterian Head Patterning Gene six3/6 Controls Aboral Domain Development in a Cnidarian, PLoS Biology, vol.296, issue.1, 2013.
DOI : 10.1371/journal.pbio.1001488.s010

M. Thomas, G. Freeman, and V. Martin, (Cnidaria, Hydrozoa), International Journal of Invertebrate Reproduction and Development, vol.219, issue.3, pp.265-285, 1987.
DOI : 10.1080/01688170.1987.10510286

J. Fritzenwanker, M. Saina, and U. Technau, Analysis of forkhead and snail expression reveals epithelial???mesenchymal transitions during embryonic and larval development of Nematostella vectensis, Developmental Biology, vol.275, issue.2, pp.389-402, 2004.
DOI : 10.1016/j.ydbio.2004.08.014

S. Dal-pra, C. Thisse, and B. Thisse, FoxA transcription factors are essential for the development of dorsal axial structures, Developmental Biology, vol.350, issue.2, pp.484-495, 2011.
DOI : 10.1016/j.ydbio.2010.12.018

P. Oliveri, K. Walton, E. Davidson, and D. Mcclay, Repression of mesodermal fate by foxa, a key endoderm regulator of the sea urchin embryo, Development, vol.133, issue.21, pp.4173-4181, 2006.
DOI : 10.1242/dev.02577

K. Wotton, F. Mazet, and S. Shimeld, Expression of FoxC, FoxF, FoxL1, and FoxQ1 genes in the dogfishScyliorhinus canicula defines ancient and derived roles for fox genes in vertebrate development, Developmental Dynamics, vol.15, issue.6, pp.1590-1603, 2008.
DOI : 10.1002/dvdy.21553

S. Koinuma, Y. Umesono, K. Watanabe, and A. K. , Planaria FoxA (HNF3) homologue is specifically expressed in the pharynx-forming cells, Gene, vol.259, issue.1-2, pp.171-17610, 2000.
DOI : 10.1016/S0378-1119(00)00426-1

C. Niehrs, Function and biological roles of the Dickkopf family of Wnt modulators, Oncogene, vol.83, issue.57, pp.7469-7481, 2006.
DOI : 10.1038/nature04185

A. Giráldez, R. Copley, and S. Cohen, HSPG Modification by the Secreted Enzyme Notum Shapes the Wingless Morphogen Gradient, Developmental Cell, vol.2, issue.5, pp.667-67610, 2002.
DOI : 10.1016/S1534-5807(02)00180-6

A. Traister, W. Shi, and J. Filmus, Mammalian Notum induces the release of glypicans and other GPI-anchored proteins from the cell surface, Biochemical Journal, vol.410, issue.3, pp.503-511, 2008.
DOI : 10.1042/BJ20070511

G. Flowers, J. Topczewska, and J. Topczewski, A zebrafish Notum homolog specifically blocks the Wnt/??-catenin signaling pathway, Development, vol.139, issue.13, pp.2416-2425, 2012.
DOI : 10.1242/dev.063206

A. Kleinschmit, M. Takemura, K. Dejima, P. Choi, and H. Nakato, Drosophila Heparan Sulfate 6-O-Endosulfatase Sulf1 Facilitates Wingless (Wg) Protein Degradation, Journal of Biological Chemistry, vol.288, issue.7, pp.5081-5089, 2013.
DOI : 10.1074/jbc.M112.447029
URL : http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3576112

H. Marlow, D. Matus, and M. Martindale, Ectopic activation of the canonical wnt signaling pathway affects ectodermal patterning along the primary axis during larval development in the anthozoan Nematostella vectensis, Developmental Biology, vol.380, issue.2, pp.324-334, 2013.
DOI : 10.1016/j.ydbio.2013.05.022

B. Hobmayer, F. Rentzsch, K. Kuhn, C. Happel, and C. Laue-von, WNT signalling molecules act in axis formation in the diploblastic metazoan Hydra, Nature, vol.407, issue.6801, pp.186-189, 2000.
DOI : 10.1038/35025063

M. Broun, Formation of the head organizer in hydra involves the canonical Wnt pathway, Development, vol.132, issue.12, pp.2907-2916, 2005.
DOI : 10.1242/dev.01848

H. Bode, The head organizer in Hydra, The International Journal of Developmental Biology, vol.56, issue.6-7-8, pp.473-478, 2012.
DOI : 10.1387/ijdb.113448hb

C. Petersen and P. Reddien, Polarized notum Activation at Wounds Inhibits Wnt Function to Promote Planarian Head Regeneration, Science, vol.332, issue.6031, pp.852-855, 2011.
DOI : 10.1126/science.1202143

T. Domazet-lo?o and D. Tautz, A phylogenetically based transcriptome age index mirrors ontogenetic divergence patterns, Nature, vol.1, issue.7325, pp.815-818, 2010.
DOI : 10.1038/nature09632

A. Kalinka, K. Varga, D. Gerrard, S. Preibisch, and D. Corcoran, Gene expression divergence recapitulates the developmental hourglass model, Nature, vol.39, issue.7325, pp.811-814, 2010.
DOI : 10.1038/nature09634

A. Rodimov, Development of Morphological Polarity in Embryogenesis of Cnidaria, Russian Journal of Developmental Biology, vol.236, issue.2, pp.298-303, 2005.
DOI : 10.1007/s11174-005-0047-1

S. Tyler, Epithelium--The Primary Building Block for Metazoan Complexity, Integrative and Comparative Biology, vol.43, issue.1, pp.55-63, 2003.
DOI : 10.1093/icb/43.1.55

S. Leys and A. Riesgo, Epithelia, an Evolutionary Novelty of Metazoans, Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, vol.164, issue.6, pp.438-447, 2012.
DOI : 10.1002/jez.b.21442

R. Raff, The Shape of Life: Genes, Development, and the Evolution of Animal Form, 1996.

G. Hemmrich and T. Bosch, Compagen, a comparative genomics platform for early branching metazoan animals, reveals early origins of genes regulating stem-cell differentiation, BioEssays, vol.132, issue.10, pp.1010-1018, 2008.
DOI : 10.1002/bies.20813

C. Fourrage, K. Swann, G. Garcia, J. Campbell, A. Houliston et al., An endogenous green fluorescent protein-photoprotein pair in Clytia hemisphaerica eggs shows co-targeting to mitochondria and efficient bioluminescence energy transfer, Open Biology, vol.19, issue.4, 2014.
DOI : 10.1016/j.cub.2008.12.054
URL : https://hal.archives-ouvertes.fr/hal-01334615