Fig. 5
From: Adoption of conserved developmental genes in development and origin of the medusa body plan
The rhopalar arm endoderm of Aurelia ephyrae shares a set of marker genes with Clytia radial tubes. a, b Oral view on a polyp. Aa-bmp5/8 expression in eight tentacle bases. c, d Lateral view on the polyp tentacles (arrowhead, pol tb. e, f) Young strobila during outgrowth of the ephyral rhopalar arms. Bmp-5/8 expression both in the remaining polyp tentacle bulbs (arrowhead) and the ephyral radial canals (arrowhead, eph rc). g, h Free ephyra. The radial canals of the eight primary rhopalar arms are Aa-bmp5/8-positive, as well as the outgrowing velar arms. i, m Broad expression of Aa-tbx4/5 in the rhopalar arms and velar arm endoderm. k–m Aa-twist is mainly expressed in a row of cells lining the canals of the gastro-vascular system. l detail of k, showing additional twist-positive cells in the endoderm between the canals