# A chromosome-level genome assembly of the European green toad (Bufotes viridis)

## TL;DR

This paper presents a high-quality chromosome-level genome assembly for the European green toad to aid conservation and genomic research.

## Contribution

The novel contribution is the creation of a chromosome-level reference genome for Bufotes viridis.

## Key findings

- The genome assembly includes 11 chromosomes and has a scaffold N50 of 478.39 Mb.
- It covers 90.4% of single copy tetrapod orthologs and predicts 23,830 protein-coding genes.
- The assembly will support conservation genetics and evolutionary genomics studies in amphibians.

## Abstract

The European green toad (Bufotes viridis) is geographically widely distributed. While the species global conservation status is labeled as of least concern by the IUCN, it is declining in many parts of its range where populations are fragmented and isolated. A high-quality reference genome is an important resource for conservation genomic researchers who are trying to understand and interpret the genomic signals of population decline, inbreeding, and the accumulation of deleterious mutations. Here, we assembled and annotated a chromosome-level reference genome for B. viridis as part of the European Reference Genome Atlas pilot project. The genome assembly, with a size of ∼3.89 Gb consists of 11 chromosomes and an additional 2,096 unplaced scaffolds. The final assembly had a scaffold N50 value of 478.39 Mb and covered 90.4% single copy tetrapod orthologs, and 46.7% repetitive elements. Finally, a total of 23,830 protein-coding genes matching a known gene, together with 56,974 mRNAs were predicted. This high-quality reference genome will benefit amphibian evolutionary genomics research and enable conservation genetic studies to inform practical conservation work on this species.