Putative origin ofMyxococcus fulvus124B02 plasmid, pMF1, from a chromosomal segment in anotherMyxococcusspecies

Myxobacteria or order Myxococcales (old nomenclature) or Phylum Myxococcota (new terminology) are fascinating organisms well known for their diverse peculiar physiological, taxonomic, and genomic properties. Researchers have long sought to identify plasmids within these organisms, yet thus far, only two organisms from different families have been found to harbor a plasmid. This study delves into the origin and evolution of one of these plasmids, i.e., pMF1 present inMyxococcus fulvus124B02 in the suborder Cystobacterineae and family Myxococcaceae. Here we first reannotated the pMF1 plasmid genome sequence and identified two additional genes that were not annotated till now. We further reported that all pMF1 plasmid genes depict homology with M. stipitatus CYD1 draft genome (contig 28) and a chromosomal segment of M. stipitatus DSM14675 in a syntenic manner, suggesting the presence of plasmid-like structure in M. stipitatus CYD1 but integrated as part of its chromosome. To comprehend the relationship among these three species, we conducted phylogenetic analyses using 16S and concatenated housekeeping genes and GGDC analysis, which confirmed that M. stipitatus CYD1 is a distinct and novel species within the genus Myxococcus. Overall, this study sheds light on the putative origin of the pMF1 plasmid, which likely originated from a closely related yet distinct species, possibly through the partition from its chromosome as a segment.