Rab32/38 expression pattern during amphioxus embryogenesis. Rab32/38 has been observed in notochord presumptive territories at the gastrula stage (a, black arrow), while later in development at the neurula stage it is expressed in notochord, mainly in the rostral part (b-c, black arrow). d is a vibratome section (15 µm) of the neurula specimen showed in b-c, at the level of the vertical dashed line. At the pre-mouth larval stage, Rab32/38 expression in the notochord turns off while a positive signal appears in the pharynx region (e, arrowhead)

Rab32a expression pattern during zebrafish embryogenesis. Rab32a has been observed in the presumptive posterior axial mesoderm (arrowhead) at 6 hpf (a) and in the developing notochord (white arrow) and Kupffer’s vesicle (arrowhead) at 8 hpf (b). At 24 hpf, it is present in RPE (white arrowhead), notochord and migrating neural crest cells (black arrows) (c-f). At 48 hpf the signal disappears in neural crest cells, but persists in RPE and notochord (white arrows) (g-h) and appears in the swim bladder (g, white asterisk). The expression in the swim bladder persists at 72 hpf larvae (i-j, white asterisk)

Rab38s expression pattern during zebrafish embryogenesis. Rab38a is expressed across the pharyngula embryonic period (24–48 hpf) (a-d): at 24 hpf there is a faint signal in RPE (arrowhead) and a strong one in migrating melanoblasts (a, b, white arrowhead) and a low level of expression is detectable in the mid-ventral region of brain (a); at 48 hpf the expression is visible only in the RPE (black arrowhead) (c, d). Rab38b is expressed only at late developmental stages (e-h): at 48 hpf in a small region of the pharyngeal arches (white arrow) and in the developing swim bladder (e, f, white asterisks), while at 72 hpf only in swim bladder (g, h, white asterisks). The gene Rab38c gene is strongly expressed in the head region (i and j for 24 hpf larvae). Lateral view in all images (anterior is on the left) except d and f that are ventral (anterior on the top)