SCAN:Cilia length and motility dictate left-right position of internal organs

ITQB Scan Seminar

Title: Cilia length and motility dictate left-right position of internal organs

Speaker: Susana Lopes

Affiliation: Group Leader-Cilia Regulation and Disease Lab-CEDOC

Abstract:

Cilia length and motility dictate left-right position of internal organs

Motile cilia are widely used to generate propelling forces that enable swimming or to allow fluid motion within animal body cavities. One such ciliated body cavity is the left-right organizer, present during embryogenesis in most vertebrates including humans. The left-right organizer’s fluid flow, created by motile cilia, is crucial to start a conserved cascade of gene expression on the left side of the vertebrate embryo that culminates with correct viscera positioning. It is still not clear how this fluid flow triggers gene expression. Nevertheless a mechanosensory mechanism has been suggested but it remains to be demonstrated.

Using zebrafish as a model organism, our group has been studying how cilia length regulation and motility affect organ laterality during embryonic development. We performed high-speed video microscopy to record live cilia beat frequency. By decomposing and comparing the obtained frequencies with Fast Fourier Transform we have identified two different populations of motile cilia inside the zebrafish left-right organizer. By modeling the different cilia beat frequencies measured experimentally, we could predict a new fluid flow pattern compatible with our observations. We have found out a relationship between fluid flow properties and liver position in the same embryos.