Evaluating DNA methylation’s link to alternative splicing in the Nevada dampwood termite

Termites rank among the most successful species and represent one of two major clades of eusocial insects.  As such, termites are defined by a caste system, whereby individuals may develop different phenotypes.  The development of alternate phenotypes in eusocial insects typically occurs through differential environmental induction of gene expression.  Recent investigations indicate that epigenetic information in the form of DNA methylation plays a fundamentally important role in regulating the development of environmentally induced patterns of gene expression.   Despite this, all studies to date exploring epigenetic differences between eusocial insect alternative phenotypes have been limited to the order Hymenoptera.  Here, we present a first look at the genome-wide DNA methylation patterns of four castes of the Nevada dampwood termite (Zootermopsis nevadensis).  We find that Z. nevadensis possesses substantially higher levels of DNA methylation than found in hymenopteran eusocial insects.  We further incorporate paired transcriptome sequencing, facilitating the evaluation of DNA methylation’s relationship with gene expression differences genome-wide. This provides insight into how epigenetic variation relates to the regulation of gene expression in a totally novel eusocial insect system.