Figure 8

Sequence and expression analysis of Has-vm1. The putative full length Has-vm1 transcript encodes an ORF of 245 amino acid residues. A putative signal sequence (↑), glycosylation sites (highlighted black) and polyadenylation signal (bold) are indicated. Primers used to assess temporal expression are boxed. (B – E) anterior views. (B) Has-vm1 expression begins approximately 60 hours post fertilisation (hpf) in a pair of cells located in the dorsal mantle edge of the veliger larva. Eyespots are indicated by white arrows. (C) By 72 hpf expression has expanded to 3 cells in the dorsal mantle edge. (D). An 84 hpf larva with 4 Has-vm1 positive mantle edge cells. The chitinised teeth of the radula (r) are visible. (E). By 132 hpf expression of Has-vm1 forms an asymmetrical, left sided pattern in 9–10 cells along the mantle edge, and is maintained in this way until metamorphosis is induced. (F-I) Corresponding right side lateral views of the larvae depicted in B-E. (J) Following metamorphosis expression of Has-vm1 proliferates along the mantle edge of 1 mm juveniles; (K) expanded boxed section in J. The discrete, punctate expression observed in competent veligers has now become a continuous line of cells along the entire length of the mantle edge.