Revisiting genomes of non-model species with long reads yields new insights into their biology and evolution

Front Genet. 2024 Feb 7:15:1308527. doi: 10.3389/fgene.2024.1308527. eCollection 2024.

Abstract

High-quality genomes obtained using long-read data allow not only for a better understanding of heterozygosity levels, repeat content, and more accurate gene annotation and prediction when compared to those obtained with short-read technologies, but also allow to understand haplotype divergence. Advances in long-read sequencing technologies in the last years have made it possible to produce such high-quality assemblies for non-model organisms. This allows us to revisit genomes, which have been problematic to scaffold to chromosome-scale with previous generations of data and assembly software. Nematoda, one of the most diverse and speciose animal phyla within metazoans, remains poorly studied, and many previously assembled genomes are fragmented. Using long reads obtained with Nanopore R10.4.1 and PacBio HiFi, we generated highly contiguous assemblies of a diploid nematode of the Mermithidae family, for which no closely related genomes are available to date, as well as a collapsed assembly and a phased assembly for a triploid nematode from the Panagrolaimidae family. Both genomes had been analysed before, but the fragmented assemblies had scaffold sizes comparable to the length of long reads prior to assembly. Our new assemblies illustrate how long-read technologies allow for a much better representation of species genomes. We are now able to conduct more accurate downstream assays based on more complete gene and transposable element predictions.

Keywords: Nematoda; genome annotation; genome assembly; genomics; long reads.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This project was supported through a DFG Emmy Noether Program (ENP) Projekt (434028868) and the DFG funded project B08 in the CRC1211 (268236062) to PHS. NG’s position was first funded through a Deutsche Forschungsgemeinschaft (DFG) grant (458953049) to PHS and subsequently through the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 101110569.