# Improved chromosome-level genome assembly of the American cockroach, Periplaneta americana

## TL;DR

Scientists improved the genome assembly of the American cockroach, making it easier to study its biology and evolution.

## Contribution

A high-quality, chromosome-level genome assembly of Periplaneta americana was generated, including a previously missing chromosome.

## Key findings

- The genome was assembled into 17 scaffolds with a scaffold N50 of 188.1 Mb.
- The assembly includes a chromosome missing in previous references and achieved a BUSCO score of 99.7%.
- Annotation identified 16,750 protein-coding genes with a BUSCO score of 97.8%.

## Abstract

The American cockroach, Periplaneta americana, is a cosmopolitan insect notorious for thriving among humans undeterred by attempts to eliminate it. The traits that contribute to its ubiquity as an opportunistic pest, such as long lifespan, expansive neurosensory capacity, and nutritional flexibility, also make P. americana an excellent invertebrate model organism as evidenced by its long history in neuroscience and physiological research. Current genetic resources available for P. americana highlight its large, complex genome and richly diverse transcriptional capabilities, but fall short of producing a complete, chromosome-level genome. Here, we present a high-quality de novo genome assembly of a laboratory-raised adult female P. americana using a combination of high fidelity PacBio long reads and Hi-C sequencing. The final 3.23 Gb genome was assembled with chromosomal resolution into 17 scaffolds, consistent with previous karyotype analysis, and has a scaffold N50 of 188.1 Mb and genome Benchmarking Universal Single-Copy Ortholog (BUSCO) score of 99.7%. This assembly includes a chromosome that was missing from the previous reference genome for this species. Protein prediction and annotation were performed via the NCBI Eukaryotic Genome Annotation Pipeline, which identified 16,750 protein-coding genes and generated an annotation BUSCO score of 97.8%. Ortholog comparisons with available Blattodea assemblies highlight the expanded chemosensory and immune capabilities of P. americana compared to termite relatives. This genome assembly is a valuable tool for facilitating future research on the biology and evolution of this remarkable insect.