# In vitro approaches to study centriole and cilium function in early mouse embryogenesis

## TL;DR

This study explores how centrioles and cilia function during early mouse embryogenesis using 3D in vitro models.

## Contribution

The study introduces 3D in vitro models to investigate centriole and cilium roles during mouse embryogenesis.

## Key findings

- Centrioles and cilia are not essential for polarization and lumenogenesis in 3D rosettes.
- Centriole loss in gastruloids can be rescued by p53 deletion.
- Cilia formation is possible in 3D models even when absent in 2D cultures.

## Abstract

This study presents an in vitro analysis of centriole and cilium formation during early mouse embryonic development, using 3D models to mimic implantation, tissue patterning, and axis elongation, offering a controlled platform for investigating their roles in embryogenesis.

Although centrioles and primary cilia play an essential role in early mammalian development, their specific function during the interval between their initial formation and the subsequent arrest of embryogenesis in embryos deficient in centrioles or cilia remains largely unexplored. Here, we demonstrate that different 3D in vitro model systems recapitulate early centriole and cilium formation in mouse development. Centrioles and cilia are dispensable in 3D in vitro mouse rosettes, a model system that mimics key events of implantation, including polarization and lumenogenesis. In gastruloids, a model system that recapitulates developmental processes up to E8.5, centriole loss results in early disassembly that can be rescued by additional p53 deletion. In contrast, cells devoid of cilia continue to form elongated, differentiated and polarized gastruloids, with minor differences at 96 h. Finally, we show that in a mutant affecting the centriolar distal appendages, cilia are absent from 2D cultures, but are capable of forming in 3D rosettes and gastruloids, highlighting the importance of multifactorial 3D environment setups in developmental studies.