Sex-specific changes in the aphid DNA methylation landscape

Area of Science:

• Epigenetics
• Genomics
• Aphid Biology

Background:

• Aphids exhibit phenotypic plasticity, producing genetically identical morphs in response to environmental cues.
• Epigenetic mechanisms, like DNA methylation, are crucial for regulating gene expression and development.
• Understanding methylation in aphids provides insights into the genetic basis of their diverse life cycles.

Purpose of the Study:

• To conduct the first comprehensive analysis of DNA cytosine methylation in the green peach aphid (Myzus persicae).
• To investigate the differences in methylation and gene expression landscapes between male and asexual female aphid morphs.
• To explore the role of differential DNA methylation in aphid sexual differentiation.

Main Methods:

• Whole genome bisulphite sequencing (WGBS) to map DNA methylation.
• Transcriptome sequencing (RNA-seq) to analyze gene expression.
• Comparative analysis of methylation and expression profiles between male and asexual female morphs.

Main Results:

• DNA methylation in M. persicae primarily occurs in CpG contexts, with exons showing enrichment, especially at the 3' end.
• Methylation positively correlates with gene expression stability and levels.
• Distinct methylation profiles exist between male and asexual female morphs, with significant divergence on sex chromosomes versus autosomes.
• Males exhibit hypomethylation of autosomal genes and hypermethylation of sex chromosome genes compared to asexual females.

Conclusions:

• Differential DNA methylation, particularly on sex chromosomes, is linked to sexual differentiation in aphids.
• Correlated changes in methylation and gene expression between morphs highlight the regulatory role of epigenetics.
• This study establishes a foundation for future research into aphid epigenetics and developmental plasticity.