NF-YA isoforms with alternative splicing of exon-5 in Aves

Area of Science:

• Molecular Biology
• Developmental Biology
• Genomics

Background:

• NF-YA is a key regulatory subunit of the NF-Y transcription factor.
• Vertebrates typically express NF-YAl and NF-YAs isoforms, differing by exon-3.
• NF-YAx, lacking exons-3 and -5, was previously identified only in human neuronal contexts.

Purpose of the Study:

• To investigate the expression of NF-YAx and identify novel NF-YA isoforms.
• To characterize the prevalence and developmental role of NF-YA isoforms in Aves.
• To analyze the structural impact of alternative splicing on NF-YA isoforms.

Main Methods:

• RT-PCR to detect and confirm NF-YA isoform expression.
• Comparative analysis of NF-YA isoform abundance across species (Aves, reptiles).
• AlphaFold protein structure prediction for NF-YAg and NF-YAx.

Main Results:

• Evidence for NF-YAx expression and discovery of a new isoform, NF-YAg (skipping exon-5).
• These isoforms are abundant in Aves and prevalent during early chicken embryo development.
• AlphaFold analysis revealed that exon-5 absence reduces beta-stranded elements, while exon-3 removal has minor effects on the Trans-Activation Domain.

Conclusions:

• An expanded repertoire of NF-YA isoforms exists in the Trans-Activation Domain in Aves.
• These novel isoforms likely play a significant role in avian early development.
• Alternative splicing of NF-YA provides a mechanism for regulatory diversity in development.