ZFIN ID: ZDB-PUB-150429-4
scaRNAs Regulate Splicing and Vertebrate Heart Development
Patil, P., Kibiryeva, N., Uechi, T., Marshall, J., O'Brien, J.E., Artman, M., Kenmochi, N., Bittel, D.C.
Date: 2015
Source: Biochimica et biophysica acta. Molecular basis of disease   1852(8): 1619-29 (Journal)
Registered Authors: Kenmochi, Naoya, Uechi, Tamayo
Keywords: Congenital heart defects, Splicing, Tetralogy of Fallot, Zebrafish, scaRNA, spliceosome
MeSH Terms:
  • Alternative Splicing/genetics*
  • Animals
  • Animals, Genetically Modified
  • Cells, Cultured
  • Coiled Bodies/genetics*
  • Embryo, Nonmammalian
  • Gene Expression Regulation, Developmental
  • Heart/embryology*
  • Heart/growth & development*
  • Heart Defects, Congenital/embryology
  • Heart Defects, Congenital/genetics
  • Humans
  • Infant
  • Infant, Newborn
  • MicroRNAs/physiology*
  • Vertebrates/embryology
  • Vertebrates/genetics
  • Vertebrates/growth & development
  • Zebrafish
PubMed: 25916634 Full text @ BBA Molecular Basis of Disease
Alternative splicing (AS) plays an important role in regulating mammalian heart development, but a link between misregulated splicing and congenital heart defects (CHDs) has not been shown. We reported that more than 50% of genes associated with heart development were alternatively spliced in the right ventricle (RV) of infants with tetralogy of Fallot (TOF). Moreover, there was a significant decrease in the level of 12 small cajal body-specific RNAs (scaRNAs) that direct the biochemical modification of specific nucleotides in spliceosomal RNAs. We sought to determine if scaRNA levels influence patterns of AS and heart development. We used primary cells derived from the RV of infants with TOF to show a direct link between scaRNA levels and splice isoforms of several genes that regulate heart development (e.g., GATA4, NOTCH2, DAAM1, DICER1, MBNL1 and MBNL2). In addition, we used antisense morpholinos to knock down the expression of two scaRNAs (scarna1 and snord94) in zebrafish and saw a corresponding disruption of heart development with an accompanying alteration in splice isoforms of cardiac regulatory genes. Based on these combined results, we hypothesize that scaRNA modification of spliceosomal RNAs assists in fine tuning the spliceosome for dynamic selection of mRNA splice isoforms. Our results are consistent with disruption of splicing patterns during early embryonic development leading to insufficient communication between the first and second heart fields, resulting in conotruncal misalignment and TOF. Our findings represent a new paradigm for determining the mechanisms underlying congenital cardiac malformations.