The genome sequence of the Oak Hook-tip, Watsonalla binaria (Hufnagel, 1767)

We present a genome assembly from an individual female Watsonalla binaria (the Oak Hook-tip; Arthropoda; Insecta; Lepidoptera; Drepanidae). The genome sequence is 333.0 megabases in span. Most of the assembly is scaffolded into 33 chromosomal pseudomolecules, including the W and Z sex chromosomes. The mitochondrial genome has also been assembled and is 15.24 kilobases in length. Gene annotation of this assembly on Ensembl identified 16,002 protein coding genes.


Background
The Oak Hook-tip, Watsonalla binaria, is a species of moth from the family Drepanidae, or 'Hook-tip' moths.This family gets its name from the shape of its tip at the forewings (Kimber, 2023).One of the smallest members of Drepanidae, W. binaria has a wingspan of 18 to 30 mm.Some distinctive features used for identification are: two pale cross-lines on its orange-brown forewings, two prominent twin dark spots on its forewings, and two central hindwing spots (Lewis, 2020).
The Oak Hook-tip is attracted to light and is mainly nocturnal.It can be found across most of Europe and is quite common in the UK, except for Scotland.Its main habitats are oak woodland and parkland, where oak is the primary food source for the larva, although it has been documented to feed on alder, beech, and birch (NatureSpot, 2022).The species overwinters as a pupa.Two broods are usually produced, one flying in May and June, and the second flying in August.The second brood of moths are smaller and lighter in colour.
The Oak Hook-tip is listed as "vulnerable" with continued steep population decline (Fox et al., 2019).
The genome of the Oak Hook-tip was sequenced as part of the Darwin Tree of Life Project, a collaborative effort to sequence all named eukaryotic species in the Atlantic Archipelago of Britain and Ireland.

Genome sequence report
The genome was sequenced from one female Watsonalla binaria (Figure 1) collected from Wytham Woods, Oxfordshire, UK (51.77, -1.34).A total of 70-fold coverage in Pacific Biosciences single-molecule HiFi long reads and 102-fold coverage in 10X Genomics read clouds were generated.Primary assembly contigs were scaffolded with chromosome conformation Hi-C data.Manual assembly curation corrected 7 missing joins or mis-joins, reducing the scaffold number by 12.2%.
The final assembly has a total length of 333.0 Mb in 36 sequence scaffolds with a scaffold N50 of 11.6 Mb (Table 1).Most (99.97%) of the assembly sequence was assigned to 33 chromosomal-level scaffolds, representing 31 autosomes and the W and Z sex chromosomes.Chromosome-scale scaffolds confirmed by the Hi-C data are named in order of size (Figure 2-Figure 5; Table 2).While not fully phased, the assembly deposited is of one haplotype.Contigs corresponding to the second haplotype have also been deposited.The mitochondrial genome was also assembled and can be found as a contig within the multifasta file of the genome submission.
Metadata for specimens, spectral estimates, sequencing runs, contaminants and pre-curation assembly statistics can be found at https://links.tol.sanger.ac.uk/species/721165.

Sample acquisition and nucleic acid extraction
A female Watsonalla binaria (ilWatBina1) was collected from Wytham Woods, Oxfordshire (biological vice-county Berkshire) (latitude 51.77, longitude -1.34) on 2020-08-01.The specimen was taken from woodland habitat by Douglas Boyes (University of Oxford),using a light trap.The specimen was identified by the collector and preserved on dry ice.
DNA was extracted at the Tree of Life laboratory, Wellcome Sanger Institute (WSI).The ilWatBina1 sample was weighed and dissected on dry ice with tissue set aside for Hi-C sequencing.Abdomen tissue was disrupted using a Nippi Powermasher fitted with a BioMasher pestle.High molecular weight (HMW) DNA was extracted using the Qiagen MagAttract HMW DNA extraction kit.Low molecular weight DNA was removed from a 20 ng aliquot of extracted DNA using the 0.8X AMpure XP purification kit prior to 10X Chromium sequencing; a minimum of 50 ng DNA was submitted for 10X sequencing.HMW DNA was sheared into an average fragment size of 12-20 kb in a Megaruptor 3 system with speed setting 30.Sheared DNA was purified by solid-phase reversible immobilisation using AMPure PB beads with a 1.8X ratio of beads to  sample to remove the shorter fragments and concentrate the DNA sample.The concentration of the sheared and purified DNA was assessed using a Nanodrop spectrophotometer and Qubit Fluorometer and Qubit dsDNA High Sensitivity Assay kit.Fragment size distribution was evaluated by running the sample on the FemtoPulse system.

Sequencing
Pacific Biosciences HiFi circular consensus and 10X Genomics read cloud DNA sequencing libraries were constructed according to the manufacturers' instructions.DNA sequencing was performed by the Scientific Operations core at the WSI on Pacific Biosciences SEQUEL II (HiFi) and Illumina NovaSeq 6000 (10X) instruments.Hi-C data were also generated from head and thorax tissue of ilWatBina1 using the Arimav2 kit and sequenced on the Illumina NovaSeq 6000 instrument.

Genome assembly, curation and evaluation
Assembly was carried out with Hifiasm (Cheng et al., 2021) and haplotypic duplication was identified and removed with

Genome annotation
The BRAKER2 pipeline (Brůna et al., 2021) was used in the default protein mode to generate annotation for the Watsonalla binaria assembly (GCA_929442735.1). in Ensembl Rapid Release.

Wellcome Sanger Institute -Legal and Governance
The materials that have contributed to this genome note have been supplied by a Darwin Tree of Life Partner.The submission of materials by a Darwin Tree of Life Partner is subject to the 'Darwin Tree of Life Project Sampling Code of Practice', which can be found in full on the Darwin Tree of Life website here.By agreeing with and signing up to the Sampling Code of Practice, the Darwin Tree of Life Partner agrees they will meet the legal and ethical requirements and standards set out within this document in respect of all samples acquired for, and supplied to, the Darwin Tree of Life Project.
Further, the Wellcome Sanger Institute employs a process whereby due diligence is carried out proportionate to the nature of the materials themselves, and the circumstances under which they have been/are to be collected and provided for use.The purpose of this is to address and mitigate any potential legal and/or ethical implications of receipt and use of the materials

Software tool Version
as part of the research project, and to ensure that in doing so we align with best practice wherever possible.The overarching areas of consideration are: • Ethical review of provenance and sourcing of the material

Figure 2 .
Figure 2. Genome assembly of Watsonalla binaria, ilWatBina1.1:metrics.The BlobToolKit Snailplot shows N50 metrics and BUSCO gene completeness.The main plot is divided into 1,000 size-ordered bins around the circumference with each bin representing 0.1% of the 333,062,894 bp assembly.The distribution of scaffold lengths is shown in dark grey with the plot radius scaled to the longest scaffold present in the assembly (16,345,438 bp, shown in red).Orange and pale-orange arcs show the N50 and N90 scaffold lengths (11,581,856 and 7,711,609 bp), respectively.The pale grey spiral shows the cumulative scaffold count on a log scale with white scale lines showing successive orders of magnitude.The blue and pale-blue area around the outside of the plot shows the distribution of GC, AT and N percentages in the same bins as the inner plot.A summary of complete, fragmented, duplicated and missing BUSCO genes in the lepidoptera_odb10 set is shown in the top right.An interactive version of this figure is available at https://blobtoolkit.genomehubs.org/view/ilWatBina1.1/dataset/ CAKNBE01/snail.

Figure 5 .
Figure 5. Genome assembly of Watsonalla binaria, ilWatBina1.1:Hi-C contact map of the ilWatBina1.1 alternate haplotype assembly, visualised using HiGlass.Chromosomes are shown in order of size from left to right and top to bottom.An interactive version of this figure may be viewed at https://genome-note-higlass.tol.sanger.ac.uk/l/?d=BZpk7k1kSBK9u8CP0jPDdg.

Table 3
contains a list of relevant software tool versions and sources.

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Legality of collection, transfer and use (national and international) Each transfer of samples is further undertaken according to a Research Collaboration Agreement or Material Transfer Agreement entered into by the Darwin Tree of Life Partner, Genome Research Limited (operating as the Wellcome Sanger Institute), and in some circumstances other Darwin Tree of Life collaborators.

the rationale for creating the dataset(s) clearly described? Yes Are the protocols appropriate and is the work technically sound? Yes Are sufficient details of methods and materials provided to allow replication by others? Yes Are the datasets clearly presented in a useable and accessible format? Yes
Competing Interests: No competing interests were disclosed.Reviewer Expertise: Genomics and Evolutionary BiologyI