# Circlator: automated circularization of genome assemblies using long sequencing reads

## TL;DR

Circlator is a new tool that automatically circularizes genome assemblies using long sequencing reads, improving accuracy for circular sequences.

## Contribution

Circlator is the first automated tool for circularizing genome assemblies from long-read sequencing data.

## Key findings

- Circlator correctly circularized 26 out of 27 circularizable sequences using Pacific Biosciences and Oxford Nanopore data.
- The tool successfully handled bacterial chromosomes, plasmids, and organelle genomes like those from Plasmodium falciparum and human mitochondria.

## Abstract

The assembly of DNA sequence data into finished genomes is undergoing a renais-sance thanks to emerging technologies producing reads of tens of kilobases. Assembling complete bacterial and small eukaryotic genomes is now possible, but the final step of circularizing sequences remains unsolved. Here we present Circlator, the first tool to automate assembly circularization and produce accurate linear rep-resentations of circular sequences. Using Pacific Biosciences and Oxford Nanopore data, Circlator correctly circularized 26 of 27 circularizable sequences, comprising 11 chromosomes and 12 plasmids from bacteria, the apicoplast and mitochondrion of Plasmodium falciparum and a human mitochondrion. Circlator is available at http://sanger-pathogens.github.io/circlator/.