The e14 cryptic prophage belongs to a temperate phage lineage distributed across Escherichia and retains genes with potential anti-phage defence functions
Year: 2026
Type: preprint
Abstract: The e14 region of Escherichia coli str. K-12 is a cryptic prophage that retains functional excision and integration machinery despite extensive loss of phage reproductive functions. However, its evolutionary relationship to other bacteriophages remains poorly resolved. Here, we identify related prophages across four Escherichia species, alongside related, independently isolated bacteriophages. The putative prophages were 34.7–43.5 kb, more than twice the size of e14 (15.2 kb), and retained much of the genomic architecture required for phage reproduction. Comparative genomic and phylogenetic analyses support e14 as a highly reduced member of a broader lineage of temperate bacteriophages. The retention of genes with established or putative anti-phage functions further raises the possibility that e14 represents a form of ‘defence flotsam’, potentially protecting its host against subsequent phage infections. More broadly, cryptic prophages may provide reservoirs of anti-phage defence functions long after losing their capacity for phage reproduction.
DOI: 10.32942/x2w996
Author: Danna R Gifford
Institution: University of Manchester
Language: English
Subfield: Virology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7223245042