RT Journal Article SR Electronic T1 Distinct spatiotemporal contribution of morphogenetic events and mechanical tissue coupling during Xenopus neural tube closure JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.06.01.446407 DO 10.1101/2021.06.01.446407 A1 Neophytos Christodoulou A1 Paris A. Skourides YR 2021 UL http://biorxiv.org/content/early/2021/06/01/2021.06.01.446407.abstract AB Neural tube closure (NTC) is a fundamental process during vertebrate embryonic development and is indispensable for the formation of the central nervous system. Here, using Xenopus laevis embryos, live imaging, single cell tracking, optogenetics and loss of function experiments we examine the contribution of convergent extension (CE) and apical constriction (AC) and we define the role of the surface ectoderm (SE) during NTC. We show that NTC is a two-stage process and that CE and AC do not overlap temporally while their spatial activity is distinct. PCP driven CE is restricted to the caudal part of the neural plate (NP) and takes place during the first stage. CE is essential for correct positioning of the NP rostral most region in the midline of the dorsoventral axis. AC occurs after CE throughout the NP and is the sole contributor of anterior NTC. We go on to show that the SE is mechanically coupled with the NP providing resistive forces during NTC. Its movement towards the midline is passive and driven by forces generated through NP morphogenesis. Last, we show that increase of SE resistive forces is detrimental for NP morphogenesis, showing that correct SE development is permissive for NTC.Competing Interest StatementThe authors have declared no competing interest.