Skip to main content
Wellcome Open Research logoLink to Wellcome Open Research
. 2023 Jun 22;8:270. [Version 1] doi: 10.12688/wellcomeopenres.19576.1

The genome sequence of the narrow-cheeked clusterfly, Pollenia angustigena (Wainwright, 1940)

Steven Falk 1, Olga Sivell 2; University of Oxford and Wytham Woods Genome Acquisition Lab; Darwin Tree of Life Barcoding collective; Wellcome Sanger Institute Tree of Life programme; Wellcome Sanger Institute Scientific Operations: DNA Pipelines collective; Tree of Life Core Informatics collective; Darwin Tree of Life Consortiuma
PMCID: PMC11437293  PMID: 39346929

Abstract

We present a genome assembly from an individual female Pollenia angustigena (the narrow-cheeked clusterfly; Arthropoda; Insecta; Diptera; Polleniidae). The genome sequence is 1370.5 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 21.01 kilobases in length. Gene annotation of this assembly on Ensembl identified 12,930 protein coding genes.

Keywords: Pollenia angustigena, narrow-cheeked clusterfly, genome sequence, chromosomal, Diptera

Species taxonomy

Eukaryota; Metazoa; Eumetazoa; Bilateria; Protostomia; Ecdysozoa; Panarthropoda; Arthropoda; Mandibulata; Pancrustacea; Hexapoda; Insecta; Dicondylia; Pterygota; Neoptera; Endopterygota; Diptera; Brachycera; Muscomorpha; Eremoneura; Cyclorrhapha; Schizophora; Calyptratae; Oestroidea; Polleniidae; Pollenia; Pollenia angustigena (Wainwright, 1940) (NCBI:txid1266490).

Background

Pollenia angustigena (Diptera, Polleniidae) is a medium-size (4.5–9.5 mm) black fly with a chequered dusting pattern on the abdomen and golden crinkly hairs on the thorax. Until recently it was placed within Calliphoridae, but the Polleninae subfamily was given family status following molecular research by Cerretti et al. (2019). The species was considered a synonym of Pollenia rudis (Fabricius, 1794), (e.g. in Van Emden (1954) it appears as P. rudis f. angustigena), but this was rectified by Rognes (1985).

This species is somewhat variable in colour and morphology (e.g. palpi are yellow to black, the basicosta is usually yellow but can be dark; the facial keel is usually sharp but is occasionally low and blunt). Pollenia angustigena can be confused with other Pollenia species, particularly P. rudis ( Draber-Mońko, 2004; Rognes, 1987; Rognes, 1991; Sivell, 2021). The characteristic golden hairs on the posterior and posteroventral surface of the middle and hind femora can occasionally be found in P. rudis (particularly in specimens from central Europe), while the middle tibia, usually with a single anterodorsal (ad) bristle, can sometimes possess 2 to 3 ad, as in P. rudis ( Rognes, 1987). Rarely the outer post-humeral bristle may be missing, as in P. griseotomentosa (Jacentkovský, 1944), however other characters should allow for a correct identification ( Rognes, 1987). The males can be reliably separated based on the shape of the distiphallus and hairs on the anteroventral surface of the hind tibia, which are reclined in P. angustigena and erect and long in P. rudis ( Rognes, 1991; Sivell, 2021). Also, the ground vestiture on the ventral side of the abdomen is reclined, and as dense as on the dorsal side, while in P. rudis the ventral vestiture is erect, and denser and finer than the dorsal vestiture. In females the shape of lateral sacs is distinctive ( Rognes, 1991).

Pollenia are parasitoids and/or predators of earthworms. The eggs are laid in small batches on the ground and hatched larvae move through soil in search of a host ( Rognes, 1991). The larvae (individually or in small groups) penetrate the worm, usually dorsally. They feed on it internally with their spiracles exposed to the outside. Third instar larva can also feed on the exterior of the worm and can move on to a different host if needed. The larvae pupate in the soil ( Keilin, 1915; Rognes, 1987; Yahnke & George, 1972).

The first instar larva of P. angustigena was described by Szpila (2003), the puparium was described by Rognes (1987); the second and third instars remain unknown.

Pollenia angustigena is closely related to P. rudis and P. pediculata Macquart, 1834, as recently shown by molecular phylogenetic analysis using the three molecular markers, COI, Ef-1α and CAD ( Szpila et al., 2023).

Pollenia angustigena is common and widely distributed in Britain ( Sivell, 2021). The adults feed on flowers, pollinating the plants ( Cerretti et al., 2019; Grzywacz et al., 2012; Jewiss-Gaines et al., 2012; Szpila, 2003). This species is found in variety of habitats including woodland, grasslands, quarries ( Draber-Mońko, 2004; Sivell, 2021). It overwinters as an adult in sheltered locations such as buildings, where it clusters, often in large numbers (hence the common name “cluster fly”), potentially causing a nuisance ( Cerretti et al., 2019; Rognes, 1987; Sivell, 2021). On the wing from March to October, although recorded all year round (in winter mainly indoors) ( Sivell, 2021).

The high-quality genome of Pollenia angustigena 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. Here we present a chromosomally complete genome sequence for Pollenia angustigena, based on one specimen from Wytham Woods.

Genome sequence report

The genome was sequenced from one female Pollenia angustigena ( Figure 1) collected from Wytham Woods, Oxfordshire, UK (51.77, –1.33). A total of 29-fold coverage in Pacific Biosciences single-molecule HiFi long reads and 28-fold coverage in 10X Genomics read clouds were generated. Primary assembly contigs were scaffolded with chromosome conformation Hi-C data. Manual assembly curation corrected 56 missing joins or mis-joins and removed 6 haplotypic duplications, reducing the assembly length by 0.35% and the scaffold number by 50.82%, and increasing the scaffold N50 by 17.67%.

Figure 1. Photograph of the Pollenia angustigena (idPolAngu1) specimen used for genome sequencing.

Figure 1.

The final assembly has a total length of 1,370.5 Mb in 30 sequence scaffolds with a scaffold N50 of 255.4 Mb ( Table 1). Most (99.96%) of the assembly sequence was assigned to 6 chromosomal-level scaffolds, representing 5 autosomes and the X sex chromosome. Chromosome-scale scaffolds confirmed by the Hi-C data are named in order of size ( Figure 2Figure 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.

Figure 2. Genome assembly of Pollenia angustigena, idPolAngu1.1: metrics.

Figure 2.

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 1,370,512,213 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 (329,103,898 bp, shown in red). Orange and pale-orange arcs show the N50 and N90 scaffold lengths (255,371,252 and 238,882,577 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 diptera_odb10 set is shown in the top right. An interactive version of this figure is available at https://blobtoolkit.genomehubs.org/view/Pollenia angustigena/dataset/CAKNFE01/snail.

Figure 5. Genome assembly of Pollenia angustigena, idPolAngu1.1: Hi-C contact map of the idPolAngu1.1 assembly, visualised using HiGlass.

Figure 5.

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=LGCnoUK1QACjBH2Tiifsmg.

Table 1. Genome data for Pollenia angustigena, idPolAngu1.1.

Project accession data
Assembly identifier idPolAngu1.1
Species Pollenia angustigena
Specimen idPolAngu1
NCBI taxonomy ID 1266490
BioProject PRJEB48114
BioSample ID SAMEA7746597
Isolate information idPolAngu1: thorax (DNA sequencing), head (Hi-C
scaffolding), abdomen (RNA sequencing)
Assembly metrics * Benchmark
Consensus quality (QV) 51.7 ≥ 50
k-mer completeness 99.97 ≥ 95%
BUSCO ** C:98.7%[S:98.1%,D:0.7%],
F:0.5%,M:0.8%,n:3,285
C ≥ 95%
Percentage of assembly mapped
to chromosomes
99.96% ≥ 95%
Sex chromosomes X chromosome localised homologous
pairs
Organelles Mitochondrial genome
assembled
complete single alleles
Raw data accessions
PacificBiosciences SEQUEL II ERR7123975, ERR7123976
10X Genomics Illumina ERR7113562–ERR7113565
Hi-C Illumina ERR7113561
PolyA RNA-Seq Illumina ERR10123660
Genome assembly
Assembly accession GCA_930367215.1
Accession of alternate haplotype GCA_930374645.1
Span (Mb) 1,370.5
Number of contigs 142
Contig N50 length (Mb) 21.0
Number of scaffolds 30
Scaffold N50 length (Mb) 255.4
Longest scaffold (Mb) 329.1
Genome annotation
Number of protein-coding genes 12,930
Number of non-coding genes 2,232
Number of gene transcripts 20,301

* Assembly metric benchmarks are adapted from column VGP-2020 of “Table 1: Proposed standards and metrics for defining genome assembly quality” from ( Rhie et al., 2021).

** BUSCO scores based on the diptera_odb10 BUSCO set using v5.3.2. C = complete [S = single copy, D = duplicated], F = fragmented, M = missing, n = number of orthologues in comparison. A full set of BUSCO scores is available at https://blobtoolkit.genomehubs.org/view/Pollenia angustigena/dataset/CAKNFE01/busco.

Figure 3. Genome assembly of Pollenia angustigena, idPolAngu1.1: BlobToolKit GC-coverage plot.

Figure 3.

Scaffolds are coloured by phylum. Circles are sized in proportion to scaffold length. Histograms show the distribution of scaffold length sum along each axis. An interactive version of this figure is available at https://blobtoolkit.genomehubs.org/view/Pollenia angustigena/dataset/CAKNFE01/blob.

Figure 4. Genome assembly of Pollenia angustigena, idPolAngu1.1: BlobToolKit cumulative sequence plot.

Figure 4.

The grey line shows cumulative length for all scaffolds. Coloured lines show cumulative lengths of scaffolds assigned to each phylum using the buscogenes taxrule. An interactive version of this figure is available at https://blobtoolkit.genomehubs.org/view/Pollenia angustigena/dataset/CAKNFE01/cumulative.

Table 2. Chromosomal pseudomolecules in the genome assembly of Pollenia angustigena, idPolAngu1.

INSDC accession Chromosome Length (Mb) GC%
OV884056.1 1 329.1 31.0
OV884057.1 2 266.48 31.5
OV884058.1 3 255.37 31.0
OV884059.1 4 249.62 31.0
OV884060.1 5 238.88 31.5
OV884061.1 X 22.52 31.5
OV884062.1 MT 0.02 20.0

The estimated Quality Value (QV) of the final assembly is 51.7 with k-mer completeness of 99.97%, and the assembly has a BUSCO v5.3.2 completeness of 98.7% (single = 98.1%, duplicated = 0.7%), using the diptera_odb10 reference set ( n = 3,285).

Metadata for specimens, spectral estimates, sequencing runs, contaminants and pre-curation assembly statistics can be found at https://links.tol.sanger.ac.uk/species/1266490.

Genome annotation report

The Pollenia angustigena genome assembly (GCA_930367215.1) was annotated using the Ensembl rapid annotation pipeline ( Table 1; https://rapid.ensembl.org/Pollenia_angustigena_GCA_930367215.1/Info/Index). The resulting annotation includes 20,301 transcribed mRNAs from 12,930 protein-coding and 2,232 non-coding genes.

Methods

Sample acquisition and nucleic acid extraction

A female Pollenia angustigena (idPolAngu1) was collected from Wytham Woods, Oxfordshire (biological vice-county Berkshire), UK (latitude 51.77, longitude –1.33) on 2020-08-04 by netting. The specimen was collected and identified by Steven Falk (independent researcher) and was then snap-frozen on dry ice.

DNA was extracted at the Tree of Life laboratory, Wellcome Sanger Institute (WSI). The idPolAngu1 sample was weighed and dissected on dry ice with tissue set aside for Hi-C sequencing. Thorax 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.

RNA was extracted from abdomen tissue of idPolAngu1 in the Tree of Life Laboratory at the WSI using TRIzol, according to the manufacturer’s instructions. RNA was then eluted in 50 μl RNAse-free water and its concentration assessed using a Nanodrop spectrophotometer and Qubit Fluorometer using the Qubit RNA Broad-Range (BR) Assay kit. Analysis of the integrity of the RNA was done using Agilent RNA 6000 Pico Kit and Eukaryotic Total RNA assay.

Sequencing

Pacific Biosciences HiFi circular consensus and 10X Genomics read cloud DNA sequencing libraries were constructed according to the manufacturers’ instructions. Poly(A) RNA-Seq libraries were constructed using the NEB Ultra II RNA Library Prep kit. DNA and RNA sequencing were performed by the Scientific Operations core at the WSI on Pacific Biosciences SEQUEL II (HiFi), Illumina NovaSeq 6000 (RNA-Seq and 10X) instruments. Hi-C data were also generated from head tissue of idPolAngu1 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 purge_dups ( Guan et al., 2020). One round of polishing was performed by aligning 10X Genomics read data to the assembly with Long Ranger ALIGN, calling variants with FreeBayes ( Garrison & Marth, 2012). The assembly was then scaffolded with Hi-C data ( Rao et al., 2014) using SALSA2 ( Ghurye et al., 2019). The assembly was checked for contamination and corrected as described previously ( Howe et al., 2021). Manual curation was performed using HiGlass ( Kerpedjiev et al., 2018) and Pretext ( Harry, 2022). The mitochondrial genome was assembled using MitoHiFi ( Uliano-Silva et al., 2022), which runs MitoFinder ( Allio et al., 2020) or MITOS ( Bernt et al., 2013) and uses these annotations to select the final mitochondrial contig and to ensure the general quality of the sequence.

A Hi-C map for the final assembly was produced using bwa-mem2 ( Vasimuddin et al., 2019) in the Cooler file format ( Abdennur & Mirny, 2020). To assess the assembly metrics, the k-mer completeness and QV consensus quality values were calculated in Merqury ( Rhie et al., 2020). This work was done using Nextflow ( Di Tommaso et al., 2017) DSL2 pipelines “sanger-tol/readmapping” ( Surana et al., 2023a) and “sanger-tol/genomenote” ( Surana et al., 2023b). The genome was analysed within the BlobToolKit environment ( Challis et al., 2020) and BUSCO scores ( Manni et al., 2021; Simão et al., 2015) were calculated.

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

Table 3. Software tools: versions and sources.

Genome annotation

The Ensembl gene annotation system ( Aken et al., 2016) was used to generate annotation for the Pollenia angustigena assembly (GCA_930367215.1). Annotation was created primarily through alignment of transcriptomic data to the genome, with gap filling via protein-to-genome alignments of a select set of proteins from UniProt ( UniProt Consortium, 2019).

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 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

  • 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.

Funding Statement

This work was supported by Wellcome through core funding to the Wellcome Sanger Institute (206194) and the Darwin Tree of Life Discretionary Award (218328).

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

[version 1; peer review: 2 approved]

Data availability

European Nucleotide Archive: Pollenia angustigena (narrow-cheeked clusterfly). Accession number PRJEB48114; https://identifiers.org/ena.embl/PRJEB48114. ( Wellcome Sanger Institute, 2022)

The genome sequence is released openly for reuse. The Pollenia angustigena genome sequencing initiative is part of the Darwin Tree of Life (DToL) project. All raw sequence data and the assembly have been deposited in INSDC databases. Raw data and assembly accession identifiers are reported in Table 1.

Author information

Members of the University of Oxford and Wytham Woods Genome Acquisition Lab are listed here: https://doi.org/10.5281/zenodo.4789928.

Members of the Darwin Tree of Life Barcoding collective are listed here: https://doi.org/10.5281/zenodo.4893703.

Members of the Wellcome Sanger Institute Tree of Life programme are listed here: https://doi.org/10.5281/zenodo.4783585.

Members of Wellcome Sanger Institute Scientific Operations: DNA Pipelines collective are listed here: https://doi.org/10.5281/zenodo.4790455.

Members of the Tree of Life Core Informatics collective are listed here: https://doi.org/10.5281/zenodo.5013541.

Members of the Darwin Tree of Life Consortium are listed here: https://doi.org/10.5281/zenodo.4783558.

References

  1. Abdennur N, Mirny LA: Cooler: Scalable storage for Hi-C data and other genomically labeled arrays. Bioinformatics. 2020;36(1):311–316. 10.1093/bioinformatics/btz540 [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Aken BL, Ayling S, Barrell D, et al. : The Ensembl gene annotation system. Database (Oxford). 2016;2016: baw093. 10.1093/database/baw093 [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Allio R, Schomaker-Bastos A, Romiguier J, et al. : MitoFinder: Efficient automated large-scale extraction of mitogenomic data in target enrichment phylogenomics. Mol Ecol Resour. 2020;20(4):892–905. 10.1111/1755-0998.13160 [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bernt M, Donath A, Jühling F, et al. : MITOS: Improved de novo metazoan mitochondrial genome annotation. Mol Phylogenet Evol. 2013;69(2):313–9. 10.1016/j.ympev.2012.08.023 [DOI] [PubMed] [Google Scholar]
  5. Cerretti P, Stireman III JO, Badano D, et al. : Reclustering the cluster flies (Diptera: Oestroidea, Polleniidae). Syst Entomol. 2019;44(4):957–972. 10.1111/syen.12369 [DOI] [Google Scholar]
  6. Challis R, Richards E, Rajan J, et al. : BlobToolKit - interactive quality assessment of genome assemblies. G3 (Bethesda). 2020;10(4):1361–1374. 10.1534/g3.119.400908 [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cheng H, Concepcion GT, Feng X, et al. : Haplotype-resolved de novo assembly using phased assembly graphs with hifiasm. Nat Methods. 2021;18(2):170–175. 10.1038/s41592-020-01056-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Di Tommaso P, Chatzou M, Floden EW, et al. : Nextflow enables reproducible computational workflows. Nat Biotechnol. 2017;35(4):316–319. 10.1038/nbt.3820 [DOI] [PubMed] [Google Scholar]
  9. Draber-Mońko A: Calliphoridae. Plujki (Insecta: Diptera). Fauna Polski 23, Warszawa: Muzeum I Instytut Zoologii.2004;23.
  10. Garrison E, Marth G: Haplotype-based variant detection from short-read sequencing. 2012; [Accessed. 10.48550/arXiv.1207.3907 [DOI] [Google Scholar]
  11. Ghurye J, Rhie A, Walenz BP, et al. : Integrating Hi-C links with assembly graphs for chromosome-scale assembly. PLoS Comput Biol. 2019;15(8): e1007273. 10.1371/journal.pcbi.1007273 [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Grzywacz A, Szpila K, Pape T: Egg morphology of nine species of Pollenia Robineau-Desvoidy, 1830 (Diptera: Calliphoridae). Microsc Res Tech. 2012;75(7):955–967. 10.1002/jemt.22020 [DOI] [PubMed] [Google Scholar]
  13. Guan D, McCarthy SA, Wood J, et al. : Identifying and removing haplotypic duplication in primary genome assemblies. Bioinformatics. 2020;36(9):2896–2898. 10.1093/bioinformatics/btaa025 [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Harry E: PretextView (Paired REad TEXTure Viewer): A desktop application for viewing pretext contact maps.2022; [Accessed 19 October 2022]. Reference Source
  15. Howe K, Chow W, Collins J, et al. : Significantly improving the quality of genome assemblies through curation. GigaScience. Oxford University Press.2021;10(1): giaa153. 10.1093/gigascience/giaa153 [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Jewiss-Gaines A, Marshall SA, Whitworth TL: Cluster flies (Calliphoridae: Polleniinae: Pollenia) of North America. Can J Arthropod Identif. 2012;19(19):1–22. 10.3752/cjai.2012.19 [DOI] [Google Scholar]
  17. Keilin D: Recherches sur les larves de Diptères Cyclorhaphes: cycle évolutif de ‘Pollenia rudis Fabr.’, parasite d’" Allolobophora chlorotica Sav.": biologie comparée des larves de Diptères. L. Lhomme.1915;49:15–198. Reference Source [Google Scholar]
  18. Kerpedjiev P, Abdennur N, Lekschas F, et al. : HiGlass: Web-based visual exploration and analysis of genome interaction maps. Genome Biol. 2018;19(1):125. 10.1186/s13059-018-1486-1 [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Manni M, Berkeley MR, Seppey M, et al. : BUSCO Update: Novel and Streamlined Workflows along with Broader and Deeper Phylogenetic Coverage for Scoring of Eukaryotic, Prokaryotic, and Viral Genomes. Mol Biol Evol. 2021;38(10):4647–4654. 10.1093/molbev/msab199 [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Rao SSP, Huntley MH, Durand NC, et al. : A 3D map of the human genome at kilobase resolution reveals principles of chromatin looping. Cell. 2014;159(7):1665–80. 10.1016/j.cell.2014.11.021 [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Rhie A, McCarthy SA, Fedrigo O, et al. : Towards complete and error-free genome assemblies of all vertebrate species. Nature. 2021;592(7856):737–746. 10.1038/s41586-021-03451-0 [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Rhie A, Walenz BP, Koren S, et al. : Merqury: Reference-free quality, completeness, and phasing assessment for genome assemblies. Genome Biology. 2020;21(1):245. 10.1186/s13059-020-02134-9 [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Rognes K: A check-list of Norwegian blow-flies (Dipt, Calliphoridae). Fauna Norvegica Ser B. 1985;32:89–93. [Google Scholar]
  24. Rognes K: The taxonomy of the Pollenia rudis species-group in the Holarctic Region (Diptera: Calliphoridae). Syst Entomol. 1987;12(4):475–502. 10.1111/j.1365-3113.1987.tb00219.x [DOI] [Google Scholar]
  25. Rognes K: Blowflies (Diptera, Calliphoridae) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica. Leiden: Brill/Scandinavian Science Press Ltd.1991;272. Reference Source [Google Scholar]
  26. Simão FA, Waterhouse RM, Ioannidis P, et al. : BUSCO: assessing genome assembly and annotation completeness with single-copy orthologs. Bioinformatics. 2015;31(19):3210–2. 10.1093/bioinformatics/btv351 [DOI] [PubMed] [Google Scholar]
  27. Sivell O: Blow flies (Diptera: Calliphoridae, Polleniidae, Rhiniidae). Handbooks for the Identification of British Insects 10(16).St Albans: Royal Entomological Society. 2021. Reference Source [Google Scholar]
  28. Surana P, Muffato M, Qi G: sanger-tol/readmapping: sanger-tol/readmapping v1.1.0 - Hebridean Black (1.1.0). Zenodo. 2023a. 10.5281/zenodo.7755665 [DOI] [Google Scholar]
  29. Surana P, Muffato M, Sadasivan Baby C: sanger-tol/genomenote v1.0.dev (v1.0.dev). Zenodo. 2023b; [Accessed 17 April 2023]. 10.5281/zenodo.6785935 [DOI] [Google Scholar]
  30. Szpila K: First instar larvae of nine West-Palaearctic species of Pollenia Robineau-Desvoidy, 1830 (Diptera: Calliphoridae). Entomol Fenn. 2003;14(4):193–210. 10.33338/ef.84188 [DOI] [Google Scholar]
  31. Szpila K, Piwczyński M, Glinkowski W, et al. : First molecular phylogeny and species delimitation of West Palaearctic Pollenia (Diptera: Polleniidae). Zool J Linn Soc. 2023;197(1):267–282. 10.1093/zoolinnean/zlac035 [DOI] [Google Scholar]
  32. Uliano-Silva M, Ferreira JGRN, Krasheninnikova K, et al. : MitoHiFi: a python pipeline for mitochondrial genome assembly from PacBio High Fidelity reads. BioRxiv. 2022. 10.1101/2022.12.23.521667 [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. UniProt Consortium: UniProt: a worldwide hub of protein knowledge. Nucleic Acids Res. 2019;47(D1):D506–D515. 10.1093/nar/gky1049 [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Van Emden FI: Diptera Cyclorrhapha, Calyptrata (I) Section (a). Tachinidae and Calliphoridae. In: Handbooks for the identification of British insects. in: Entomological Society of London,1954;133. Reference Source [Google Scholar]
  35. Vasimuddin Md, Misra S, Li H, et al. : Efficient Architecture-Aware Acceleration of BWA-MEM for Multicore Systems. In: 2019 IEEE International Parallel and Distributed Processing Symposium (IPDPS). IEEE,2019;314–324. 10.48550/arXiv.1907.12931 [DOI] [Google Scholar]
  36. Wellcome Sanger Institute: The genome sequence of the narrow-cheeked clusterfly, Pollenia angustigena (Wainwright, 1940). European Nucleotide Archive. [dataset]. accession number PRJEB48114.2022.
  37. Yahnke W, George JA: Rearing and immature stages of the cluster fly ( Pollenia rudis) (Diptera: Calliphoridae) in Ontario. Can Entomol. 1972;104(4):567–576. 10.4039/Ent104567-4 [DOI] [Google Scholar]
Wellcome Open Res. 2024 Sep 27. doi: 10.21956/wellcomeopenres.21686.r95987

Reviewer response for version 1

Alessandro Vezzi 1

Pollenia angustigena is common and widespread in the UK. This species is found in a variety of habitats and overwinters as an adult in sheltered places such as buildings, potentially causing a nuisance. Also, adults pollinate plants by feeding on flowers.

Given its wide distribution in Britain, and its ecological importance as a pollinator, it seems obvious that the genome of this species should be sequenced, assembled and annotated by the Darwin Tree of Life project.

Thanks to the sequencing effort, which involved the use of Pacific Biosciences single-molecule HiFi long reads and 10X Genomics read clouds, plus chromosome conformation Hi-C data, most of the assembly sequence was assigned to 6 chromosomal-level scaffolds, representing 5 autosomes and the X sex chromosome. The assembled genome is therefore of high quality.

The genome annotation mainly involved the use of transcriptomic data aligned to the genome, which, being of high quality, certainly enabled easy alignment and correct reconstruction of the gene structure.

I would like to suggest some improvements in some details of the experimental methods section, as

1) The 0.8X AMPure XP purification kit does not exist. By 0.8X we mean the ratio of the volume of XP beads to the volume of sample to be purified.

2) It is not clear how many ng of extracted DNA were used for 10X sequencing. In fact, initially it is written that "a 20 ng aliquot of extracted DNA" was purified before 10X Chromium sequencing. But then a minimum of 50 ng DNA was submitted for 10X sequencing. If I checked the sequencing runs correctly, you are talking about the same DNA sequenced with the same platform, so I am a little confused by the different ng used.

Two final points I noticed in the article:

1) The reference ‘Jacentkovský,

1944' is not linked to any article.

2) Elongation factor-1α must be written EF-1α.

Are sufficient details of methods and materials provided to allow replication by others?

Partly

Is the rationale for creating the dataset(s) clearly described?

Yes

Are the datasets clearly presented in a useable and accessible format?

Yes

Are the protocols appropriate and is the work technically sound?

Yes

Reviewer Expertise:

Genomics and metagenomics, sequencing tecnologies.

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

Wellcome Open Res. 2023 Sep 11. doi: 10.21956/wellcomeopenres.21686.r66119

Reviewer response for version 1

Shigeyuki Koshikawa 1

This article reports a high-quality genome sequence of the narrow-cheeked clusterfly, Pollenia angustigena. The taxonomic position and ecology of this species are briefly presented. The methods used to obtain the genome sequence are explained in an appropriate amount of detail. I believe that this report will contribute to our understanding of local biodiversity and the biology of insects in general.

Are sufficient details of methods and materials provided to allow replication by others?

Yes

Is the rationale for creating the dataset(s) clearly described?

Yes

Are the datasets clearly presented in a useable and accessible format?

Yes

Are the protocols appropriate and is the work technically sound?

Yes

Reviewer Expertise:

Evolutionary developmental biology of insects

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Data Citations

    1. Wellcome Sanger Institute: The genome sequence of the narrow-cheeked clusterfly, Pollenia angustigena (Wainwright, 1940). European Nucleotide Archive. [dataset]. accession number PRJEB48114.2022.

    Data Availability Statement

    European Nucleotide Archive: Pollenia angustigena (narrow-cheeked clusterfly). Accession number PRJEB48114; https://identifiers.org/ena.embl/PRJEB48114. ( Wellcome Sanger Institute, 2022)

    The genome sequence is released openly for reuse. The Pollenia angustigena genome sequencing initiative is part of the Darwin Tree of Life (DToL) project. All raw sequence data and the assembly have been deposited in INSDC databases. Raw data and assembly accession identifiers are reported in Table 1.


    Articles from Wellcome Open Research are provided here courtesy of The Wellcome Trust

    RESOURCES