2026/01/31 by Alun R C Jones, Alina A. Mikhailova, Cédric Aumont +9 · 2 voices
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · Neuroscience · #Insect and Arachnid Ecology and Behavior #Fossil Insects in Amber #Neurobiology and Insect Physiology Research
paper · doi:10.1093/gbe/evag028
openalex publication_date 2026/01/31 · openalex created_date 2026/02/10 · openalex updated_date 2026/07/25
Subsociality and wood-eating or xylophagy are understood as key drivers in the evolution of eusociality in Blattodea (cockroaches and termites), two features observed in the cockroach genus Cryptocercus, the sister group of all termites. We analyze two high-quality genomes from this genus, C. punctulatus from North America and C. meridianus from Southeast Asia, to explore the evolutionary transitions to xylophagy and subsociality within Blattodea. Our analyses reveal evidence of relaxed selection in both Cryptocercus and termites, indicating that a reduction in effective population size may have occurred in their subsocial ancestors. These findings challenge the expected positive correlation between dN/dS ratios and social complexity, as Cryptocercus exhibits elevated dN/dS values that may exceed those of eusocial termites. Additionally, we infer a reduction in the number of Ionotropic Receptors and a change from uni- to bimodal methylation signatures in protein coding genes in a common ancestor of Cryptocercus and termites, mechanisms previously thought to have evolved with the emergence of eusociality in termites. Future studies incorporating additional genomic data from diverse blattodean species can further build on these findings and provide deeper insights into the molecular mechanisms driving transitions to xylophagy and eusociality.