A Possible Heterodimeric Prophage-Like Element in the Genome of the Insect Endosymbiont<i>Sodalis glossinidius</i>

Abstract

Extrachromosomal element pSOG3 (52,162 nucleotides) in the genome of Sodalis glossinidius contains redundant phage-related gene pairs, indicating that it may have been formed by the fusion of two ancestral phage genomes followed by gene degradation. We suggest that pSOG3 is a prophage that has undergone genome degeneration accompanying host adaptation to symbiosis.