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.

Automated summary

The MIR449 genomic locus contains regulators of multiciliated cell formation, and miR-34b/c from the MIR34B/C locus are additional regulators. Through single-cell RNA-seq and super-resolution microscopy, the expression of BTG4, LAYN, and HOATZ in the MIR34B/C locus was characterized. These transcripts were expressed in both precursors and mature multiciliated cells. Layilin/LAYN protein was absent from primary cilia but expressed in apical membrane regions or throughout motile cilia. Silencing LAYN affected actin cap formation and multiciliogenesis. HOATZ protein was detected in primary cilia or throughout motile cilia. These findings suggest that the MIR34B/C locus may gather potential regulators of multiciliogenesis.