High resolution dynamic mapping of the C. elegans intestinal brush border

The intestinal brush border is made of an array of microvilli that increases the membrane surface area for nutrient processing, absorption, and host defense. Studies on mammalian cultured epithelial cells uncovered some of the molecular players and physical constrains required to establish this apical specialized membrane. However, the building and maintenance of a brush border in vivo has not been investigated in detail yet. Here, we combined super-resolution imaging, transmission electron microscopy and genome editing in the developing nematode C. elegans to build a high-resolution and dynamic localization map of known and new brush border markers. Notably, we show that microvilli components are dynamically enriched at the apical membrane during microvilli outgrowth and maturation but become highly stable once microvilli are built. This new toolbox will be instrumental to understand the molecular processes of microvilli growth and maintenance in vivo as well as the effect of genetic perturbations, notably in the context of disorders affecting brush border integrity.

Methods
Sanger sequencing of C. elegans genomic DNA in strains modified by CRISRP/Cas9 to add fluorophores to genetic loci.