Fig. 4: Wnt genes and jellyfish body plan formation.

a, Maximum-likelihood phylogenetic relationships (with the LG substitution model) between Wnt genes from the Anthozoa and Medusozoa. b, Several lineage-specific Wnt gene duplications occurred in Aurelia and Morbakka. ^a,bWnt gene paralogues. c, Wnt genes are dynamically expressed throughout the life cycle of Aurelia. head, segm and nseg refer to the head, segments and non-segmented part of a strobila. d, Several Wnt genes exhibit tissue-specific expression. A schematic representation of the Aurelia jellyfish is shown with ectoderm in green, muscle in red and the gastrovascular (canal) system in magenta. Filaments, gastric filaments. e–i, SEM images of a polyp and four strobilation stages in Aurelia. Scale bar: 200 µm. j–s, Expression of Wnt-11a (j–n) and Bmp5/8 (o–s) during metamorphosis of Aurelia. Transcripts were detected in the oral side of each developing ephyra anlage. Scale bars: 200 µm in j–l and o–q; 100 µm in in m, n, r and s. t, Ectopic activation of the Wnt cascade during Aurelia metamorphosis with the addition of azakenpaulone (bottom) causes defects in development and separation of ephyra compared with the control (top). u, The addition of azakenpaulone before the induction of metamorphosis completely blocks the development of segments (bottom) compared with the control (top). Scale bars: 1 mm in t and u.