Date: October 2, 2015 | 16h
Location: NMS|FCM, Main Building, Room EP10, Ground floor
Speaker: Bárbara Tavares, PhD
Post-doc from the From Cilia Regulation and Disease Lab (CEDOC)
Title: Notch signalling decides on cilia motility in the left-right organizer
It has been established that ciliary motility is dependent on the master regulator foxj1a1,2. Nevertheless, our previous work has demonstrated that Notch signalling modulates cilia motility in the left-right organizer (LRO) of the zebrafish3. In order to understand the relationship between cilia motility, Notch signalling (NS) and foxj1a activity, we monitored the transcriptional levels of her12 (NS readout in LRO), foxj1a, and the dynein motor protein dnah7, by qPCR, while manipulating NS and/or Foxj1a protein levels.
We found that dnah7 transcription is strongly regulated by Foxj1a, and indirectly by NS through the regulation of foxj1a. We then investigated the impact of overexpressing Foxj1a and modulating NS in the number of moving cilia in the LRO, and found that this parameter was dependent solely on NS, even under the overexpression of Foxj1a. We also tracked each cilium present in the LRO, from 3 to 8 somite stage and found that the majority of cilia are immotile at 3 somite stage and start to move at 4 - 5 somite stages. Still, some cilia remain immotile during the whole time period, which leads to the question: are all cilia made equal?
Our working hypothesis is that, despite having the potential to be motile, cilia in the zebrafish LRO require a cue from Notch signalling in order to initiate its movement.
1. Tian T et al. doi:10.1016/j.bbrc.2009.01.111.
2. Yu X et al. doi:10.1038/ng.263.
3. Sampaio P et al. doi:10.1016/j.devcel.2014.04.030
CEDOC Meeting "Casual Friday with Science" is organized by Teresa Barona (Molecular Mechanisms of Disease Lab)