RES complex is associated with intron definition and required for zebrafish early embryogenesis

Area of Science:

• Molecular Biology
• Developmental Biology
• Genetics

Background:

• Pre-mRNA splicing is vital for eukaryotic gene expression, regulated by RNA-binding proteins.
• The retention and splicing (RES) complex (Bud13p, Pml1p, Snu17p) is known in yeast but its vertebrate function is unclear.

Purpose of the Study:

• Investigate the role of the RES complex in vertebrate development and splicing.
• Identify intronic features associated with RES complex activity.
• Determine the RES complex's role in neural development.

Main Methods:

• Generated loss-of-function zebrafish mutants for bud13, pml1 (snip1), and snu17 (rbmx2).
• Performed transcriptomic analysis to assess splicing defects.
• Analyzed intronic features (length, GC content, flanking exon composition).
• Developed a predictive model for RES-dependent introns.

Main Results:

• RES complex components are essential for early zebrafish development, particularly neural development.
• Mutants exhibit neural defects, including increased cell death and reduced neuron differentiation.
• Global intron splicing defects were observed, with specific mis-splicing of certain introns.
• RES-dependent introns are short, GC-rich, and flanked by GC-depleted exons, characteristic of intron definition.

Conclusions:

• The RES complex plays an essential role in vertebrate development and pre-mRNA splicing.
• Specific intronic features predict RES complex-dependent splicing.
• This study provides novel insights into RES complex function and its developmental importance.