Gene capture by Helitron transposons reshuffles the transcriptome of maize

Area of Science:

• Genomics
• Molecular Biology
• Mobile Genetic Elements

Background:

• Helitrons are mobile genetic elements found across eukaryotes.
• Maize Helitrons capture gene fragments, forming chimeric transcripts.
• These chimeric transcripts can intertwine coding regions of different captured genes.

Purpose of the Study:

• Identify high-quality maize Helitrons with captured gene fragments.
• Investigate Helitron expression and transcript diversity.
• Determine the role of Helitrons in generating novel genetic diversity.

Main Methods:

• Bioinformatic analysis of the B73 maize genome for Helitrons.
• In silico expressed sequence tag (EST) analysis for Helitron expression.
• Reverse transcription-polymerase chain reaction (RT-PCR) to validate novel transcripts.

Main Results:

• Identified maize Helitrons containing fragments from multiple genes.
• RT-PCR revealed novel transcripts not present in EST databases.
• Alternative splicing and exon capture by Helitrons generate transcript diversity.
• Tissue-specific alternative splicing patterns were observed in root and shoot tissues.

Conclusions:

• Helitrons actively generate new coding regions through gene fragment capture and alternative splicing.
• Helitrons can capture nearby exons, further increasing coding potential.
• Helitrons contribute significantly to novel transcript diversity, potentially ~25% of maize genes.