Abstract

E-cadherin plays a key role in tissue morphogenesis by forming clusters that support intercellular adhesion and transmit tensile forces among cells, depending on the size, distribution, and lateral dynamics of these clusters. Our aim was to characterize E-cadherin cluster formation in vivo and correlate these findings with changes in differential cell tension/stiffness in enveloping layer cells, a phenomenon that is critical in directing the migration of neighbouring mesenchymal deep cells in the early killifish embryo. We performed in vivo visualization of E-Cadherin clusters during the complete process of A. nigripinnis epiboly using Light Sheet Microscopy combined with E-cadherin indirect immunofluorescence visualised by confocal and STORM superresolution microscopy, followed by image processing. We performed micro- and nanometric descriptions of E-cadherin clusters during epiboly and found large and small cluster populations with differential spatial distributions. Large clusters located preferentially near enveloping layer cell borders while small clusters were polydisperse. Importantly, the preferential location of E-cadherin clusters in enveloping layer cells associated with regions of higher stiffness previously described. Thus, we provide evidence of a nanoscopic organization of E-cadherin that could play a role in mechanical stress transmission. Acknowledgments: BNI (ICM-P09-015-F); VISUAL·D (Conicyt PIA ACT1402); FONDECYT 1151029 and 1161274; PAGEL-CHIP-DAAD 57168868; CENS-CORFO-16CTTS-66390; FONDAP 15150012.