scaRNA1 Expression Levels Affect Alternative Splicing of mRNA.

Our previous research identified 12 small Cajal body-specific RNAs (scaRNAs) with reduced expression in the right ventricle in infant patients with tetralogy of Fallot. Likewise, we showed that there were significant changes in mRNA processing in the RV in these patients. ScaRNAs play a crucial role in the biochemical maturation of spliceosomal RNAs (pseudouridylation and 2'-O-methylation). We showed that variations in scaRNA1 levels resulted in changes in alternative splicing in human cells. To investigate further the role that scaRNAs play in mRNA processing, we examine here the impact of knocking down scaRNA1 in quail myoblast cells (Coturnix japonica, a well-established animal model for studying embryonic development). Following the knockdown of scaRNA1, transcriptome analysis revealed that the genes Tjp1, Map3k7, and Sppl2a were alternatively spliced. Growing evidence indicates that alternative splicing of mRNA plays an important role in regulating cell differentiation and tissue development. Our data presented here provide additional support for research to clarify the specific roles that individual scaRNAs play in regulating spliceosome function and mRNA splicing.