Figure 4

Expression patterns of CheSox5, CheSox13, CheSox15, CheSox14 and CheSox2 in the medusa. (A-E) Single in situ hybridisations showing that the five genes have crescent-shaped expression patterns in the ectodermal layer of the tentacle bulb. Staining is continuous on the inner face of the bulb but interrupted on the outer face, as typical for nematogenesis genes [35]. (F-J) Double in situ hybridisations with Minicollagene 3-4 (mcol3-4a) riboprobe reveals extensive co-expression (purple staining) with CheSox5 (F), CheSox13 (G) and CheSox15 (H) but only partial co-expression, in the most distal area of the bulb, with CheSox14 (I) and CheSox2 (J). All tentacle bulbs have the same orientation, with their proximal pole on the top and tentacle on the bottom (star: tentacle base). White arrows in I and J indicate cells expressing only mcol3-4a (red staining); black arrows in I and J indicate cells expressing both genes (purple staining). (K-O) Gene expression in the female gonads. Strong staining is observed in maturing oocytes (ov) for CheSox5 (K), CheSox13 (L), CheSox14 (N) and CheSox2 (O), while no expression was detected for CheSox15 (M). Scale bars: A-J, 20 μm; K-O, 50 μm.