Circular chromosome atlas

A field guide
to genome skew.

Browse every topology-verified circular bacterial chromosome calculated from NCBI RefSeq. The gallery grows as new static records are completed.

cumulative G−C skew maximum minimum

Interpret carefully. A cumulative GC-skew minimum is a useful candidate signal, not a reliable oriC call by itself. The result depends on the assembly’s chosen linear starting coordinate; rearrangements, atypical replication biology, and weak strand asymmetry can all make the minimum misleading.

Reference assemblies are preferred, then representative assemblies, then the newest available assembly.