A microscopic approach to quantitate E-cadh expression during zebrafish embryonic epidermis development

SAMPEDRO, MARIA FLORENCIA; SIGOT VALERIA; SIGOT VALERIA; SAMPEDRO, MARIA FLORENCIA

Workshop; Bridging cell and tissue mechanics to fate specification in development; 2019

Dynamic remodeling of intercellular adhesive contacts or adherent junctions (AJs)mediated by epithelial cadherin (E-cadh) is crucial at maintaining tissue integrity and coordinating collective cell movements during animal embryogenesis.By using immunofluorescence in whole mounted embryos, and combining deconvolution and segmentation algorithms in 3D we developed an image processing protocol to estimate the E-cadh expression during epidermis development between 24 and 72 hpf.With this approach we detected a significant increase of E-cadh levels between 31 and 48 hpf, consistent with the establishments of new cell-cell contacts in the epidermal basal layer (EBL) and the visible increase in cell density in the enveloping layer (EVL).This increasing levels of E-cadh in AJs correlates with extensive changes in cell morphology towards hexagonal packing during the epidermis morphogenesis.As a novel approach, we implemented this image processing pipeline to analyze in vivo the spatio-temporal distribution of E-cadh during the migration of the posterior Lateral Line Primordium (pLLP), which has emerged as an important model system for studying many aspects of development, including collective cell migration.A preliminary study was carried out in three transgenic embryos transiently expressing E-cadh-GFP during a temporal window of pLLP migration. The E-cadh distribution was analyzed in pLLP cells over time and was correlated with changes in cell morphology. Monitoring tissues in movement are technically demanding not only regarding image acquisition in vivo, but because subsequent automated image processing and analysis is not trivial in 4D.