Model of Vash1 function in zebrafish trunk. (A-F) Microtubule detyrosination is catalysed by Vash1 (A), particularly occurring in secondary sprouts (B). In the secondary sprouts, Vash1-mediated detyrosinated microtubules keep control of the number of sprouting cells, cell proliferation and cell protrusion formation to avoid over-sprouting (C). Secondary sprouts with correctly detyrosinated microtubules form PLs at 2 dpf, which in turn form the TD at 3-4 dpf (C). Upon vash1 KD, microtubules of secondary sprouts are no longer detyrosinated (D,E). Cells of secondary sprouts over-proliferate, fail to form PLs and a functional TD, although PLs forming from veins still occur (F).
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