In all vertebrates, specialized ciliated tissues are covered with cells harboring dozens of motile cilia, beating coordinately to generate directional fluid flow. Multiciliated cells help airway cleansing, ovum implantation and cerebrospinal fluid circulation.

Thus, several human pathologies caused by ciliary defects are characterized by chronic respiratory distress, brain abnormalities and reduced fertility. However, the biology of multiciliated cells remains poorly understood, due to the paucity of accessible in vivo models. Our team studies the embryonic skin of the amphibian Xenopus laevis, which is proving very powerful to reveal molecular and cellular principles of multiciliogenesis conserved with humans.

The Xenopus laevis embryo is easily amenable to manipulation of protein-coding genes as well as non-coding RNAs (microRNAs, long non coding RNAs) through micro-injection of mRNA constructs or antisense morpholinos, from the time of fertilization. The ciliated epidermis is particularly suited for functional analysis as it can be targeted specifically and lies at the surface of the embryo, which facilitates light and electron microscopy imaging. This tissue can also easily be exposed to pharmacological compounds and recombinant proteins at various stages of its development, and subjected to transgenesis to trace and manipulate the various cell types that compose it.