Movie 3

Anastomosis in an esamaubs19 mutant embryo
Deconvolved spinning disc confocal movie of a Tg(fli1ep:gal4ff)^ubs3, Tg(UAS:EGFP-UCHD)^ubs18, Tg(kdrl:mCherry-CAAX)^s916 esama^ubs19 mutant embryo at around 32hpf, anterior to the left. Confocal stacks were acquired every minute. Single channels are shown in inversed contrast (green is EGFP-UCHD and red is mCherry-CAAX on left and right, respectively) and the merged channels are shown in the middle. Similar to wild-type embryos, two tip cells expand filopodia towards each other. Few transient filopodial interactions are observed before a single filopodial contact is maintained and reinforced by the recruitment of actin cytoskeletal components (around the 24^th minute of the movie). Shortly after, a second protrusion, made by the tip cell on the right hand side, establishes contact to the left tip cell. This second contact is quickly reinforced by actin cytoskeletal components (around the 45^th minute of the movie). As anastomosis progresses, the two contacts are fused to a single one (around 75^th minute of the movie). We also observe the establishment of two anastomotic contacts, which are then fused to a single one, in wild-type embryos. Therefore, anastomosis in the absence of Esama is comparable to wild-type.