Figure 4 | Scientific Reports

Figure 4

From: Brain regionalization genes are co-opted into shell field patterning in Mollusca

Figure 4

Expression of Gbx during ontogenesis of the bivalve Nucula tumidula. Anterior (a)-posterior (p), dorsal (d)-ventral (v) and left (l)-right (r) axes indicate the orientation. The blastopore (asterisk) leads to the definitive mouth. (a) In early test-cell larva (3 dpf) Gbx is expressed in the ectoderm on the dorsal and lateral sides. (b) In 8 dpf old test-cell larvae Gbx is expressed in the ventral mantle margins (arrowheads). (c,d) In further developed specimens (12 dpf) Gbx is expressed laterally in the mantle. The large and flattened ciliated test-cells (tc) constitute the outer cellular layer of the larva and do not express Gbx. (e) Late test-cell larvae (12 dpf) express Gbx in the region of the ventral (lower arrowhead) and lateral mantle (upper arrowhead). Note the mantle cavity (mc), the perivisceral cavity (pc), and the stomache (stm). (f) Settled, early postmetamorphic individuals (22 hpf) express Gbx in parts of the mantle close to the foot. The test-cells have been shed during metamorphosis and will eventually be ingested. Scale bars: 30 µm (except Change “I” into “f”: 50 µm).