Characterization of nematode DAF-19 and human RFX6 transcription factors

Regulatory factor X (RFX) transcription factors play an important role in regulating expression of ciliary genes associated with ciliopathies. However, the annotation of RFX genes may be incomplete and their function is not well understood. Here I describe two novel tissue-specific RFX genes in humans: RFX6 and RFX7. To study RFX genes in the model organism Caenorhabditis elegans, I undertook examining the expression of all four known isoforms of daf-19, the only RFX gene in C. elegans, by using Mos1 mediated Single Copy transgene Insertion (MosSCI) method. I discovered that both daf-19c and daf-19d isoforms are expressed in ciliated neurons and that their promoters are modular. In particular, daf-19c is expressed in all ciliated neurons while daf-19d in all but labial neurons. My analysis helped select suitable promoters for driving expression of RFX6 in ciliated neurons of C. elegans for testing its function in cilia.