An updated Gallus gallus genome annotation through multi-tissue transcriptome analysis.

Area of Science:

• Genomics
• Transcriptomics
• Animal Science

Background:

• Accurate genome annotation is crucial for understanding gene function and improving livestock.
• The Functional Annotation of Animal Genomes (FAANG) initiative aims to comprehensively characterize genome elements.
• Previous chicken genome annotations required expansion to capture full transcript diversity.

Purpose of the Study:

• To update the Gallus gallus genome annotation through comprehensive multi-tissue transcriptome analysis.
• To identify novel transcript isoforms, unannotated transcripts, and allele-specific expression (ASE) patterns.
• To provide enhanced genomic resources for poultry breeding and agricultural applications.

Main Methods:

• RNA sequencing (RNA-Seq) was performed on 20 distinct chicken tissues and cell types.
• Transcriptome data was analyzed to identify and annotate transcript isoforms, including novel ones.
• Allele-specific expression (ASE) analysis was conducted across the sampled tissues.

Main Results:

• Identification of 110,930 transcript isoforms, with approximately 37,000 previously unannotated transcripts.
• Discovery of 11,530 unique genes exhibiting allele-specific expression (ASE) across tissues.
• Characterization of tissue-specific isoforms and differentially expressed genes, particularly in reproductive and muscle tissues.

Conclusions:

• The updated genome annotation significantly expands transcript diversity and functional annotation for Gallus gallus.
• Findings highlight the importance of tissue-specific gene expression and ASE for economically important traits like fertility and meat quality.
• This research provides valuable genomic resources to support breeding strategies for disease resistance and productivity in poultry.