Single-parent expression drives dynamic gene expression complementation in maize hybrids

Area of Science:

• Plant genetics and genomics
• Gene expression regulation
• Maize (Zea mays) research

Background:

• Single-parent expression (SPE) describes genes expressed from only one parent.
• SPE can result from non-presence/absence (non-PAV) differential expression or physical gene absence (PAV).
• Understanding SPE mechanisms is crucial for plant breeding and hybrid vigor.

Purpose of the Study:

• To compare the characteristics of PAV-SPE and non-PAV-SPE genes in maize.
• To investigate the genetic and regulatory factors influencing different SPE types.
• To assess the role of SPE in gene expression complementation in maize hybrids.

Main Methods:

• Analysis of transcriptome data from 401 diverse maize inbreds and hybrids across five tissues.
• Correlation analysis between parental genetic distance and SPE gene frequency.
• Regulatory analysis focusing on cis and trans effects, including transposable elements.

Main Results:

• SPE is highly genotype and tissue-specific, with higher incidence correlated with greater parental genetic distance.
• Both PAV-SPE and non-PAV-SPE genes are primarily regulated by cis effects, influenced by polymorphic transposable elements.
• PAV-SPE genes show higher expression in hybrids; silent allele expression in non-PAV-SPE hybrids can lead to non-additive expression.

Conclusions:

• PAV-SPE and non-PAV-SPE exhibit distinct genetic and regulatory properties in maize.
• Transposable elements significantly contribute to cis-regulation in both SPE types.
• SPE plays a role in gene expression complementation, influencing hybrid performance in maize.