The MIR34B/C genomic region contains multiple potential regulators of multiciliogenesis

The MIR449 genomic locus encompasses several regulators of multiciliated cell (MCC) formation (multiciliogenesis). The miR‐449 homologs miR‐34b/c represent additional regulators of multiciliogenesis that are transcribed from another locus. Here, we characterized the expression of BTG4, LAYN, and HOATZ, located in the MIR34B/C locus using single‐cell RNA‐seq and super‐resolution microscopy from human, mouse, or pig multiciliogenesis models. BTG4, LAYN, and HOATZ transcripts were expressed in both precursors and mature MCCs. The Layilin/LAYN protein was absent from primary cilia, but it was expressed in apical membrane regions or throughout motile cilia. LAYN silencing altered apical actin cap formation and multiciliogenesis. HOATZ protein was detected in primary cilia or throughout motile cilia. Altogether, our data suggest that the MIR34B/C locus may gather potential actors of multiciliogenesis. Using single‐cell RNA‐seq and super‐resolution microscopy from several multiciliogenesis models, we show that BTG4, LAYN, and HOATZ, three proximal genes of the MIR34B/C locus, are expressed in precursors and mature multiciliated cells (MCCs). This graphical illustrates the localization of Layilin/LAYN and HOATZ in motile cilia of MCCs. Our data suggest that the MIR34B/C locus may gather potential actors of multiciliogenesis.