Dominance and Sexual Dimorphism Pervade the Salix purpurea L. Transcriptome

Area of Science:

• Genomics
• Plant Biology
• Molecular Genetics

Background:

• Heritability of gene expression is key to understanding heterosis.
• Allele-specific regulation by genomic factors influences gene expression.
• Intraspecific variation in gene expression is influenced by regulatory divergence.

Purpose of the Study:

• To investigate the heritability of gene expression in Salix purpurea.
• To determine the role of cis- and trans-regulatory divergence in gene expression variation.
• To explore sexually dimorphic patterns of gene expression inheritance.

Main Methods:

• RNA-Seq was employed to analyze gene expression in F1 and F2 intraspecific progeny.
• Allele-specific expression was assessed in shoot tip and stem internode tissues.
• Inheritance patterns were analyzed considering parental allele expression levels.

Main Results:

• Gene expression inheritance in Salix purpurea predominantly shows a maternal dominant pattern.
• A higher number of cis- and trans-regulated genes exhibited maternal allele upregulation.
• Sex-biased gene expression was localized to a 2 Mb region on chromosome 15, refining the sex determination region.

Conclusions:

• Maternal dominance is a significant mode of gene expression inheritance in Salix purpurea.
• Regulatory divergence contributes to variation in gene expression, with distinct patterns for maternal and paternal alleles.
• Sexually dimorphic expression patterns provide evidence for the evolution of dioecy in Salix.