Electron microscopy ascertains presence of centrioles in rectal epithelial cells of C. elegans L1 larvae

Centrioles are microtubule-based organelles important for cellular organization and function. <i>C. elegans</i> embryos undergo extensive programmed centriole elimination, with merely 7 post-mitotic cells retaining a focus of the centriolar proteins SAS-4 and SAS-7 in L1 larvae. Here, we addressed whether such foci correspond to <i>bona fide</i> centrioles by conducting serial-section electron microscopy. Our analysis ascertains that centriolar microtubule configurations are indeed present in the B, F, U and Y rectal epithelial cells. Therefore, centrioles are truly spared from elimination in these cells, calling for investigating the importance of such retention compared to the elimination program occurring in most post-mitotic cells.