Biology subjects

Roe, D.

Publications and source records attributed to Roe, D..

9 recordsLinked to original sources

bioRxiv2024

Disproportionate regulation of wildlife trade

An increasing number of countries in the Global North have enacted, or are considering, import bans on hunting trophies with the aim of protecting wildlife. We interrogate key arguments used to characterize trophy hunting and associated trade by proponents of such bans, using data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) over 25 years (2000-2024), the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and empirical research. Contrary to claims by proponents of bans, we show that trophy hunting is not a major threat to any CITES-listed species traded as a hunting trophy in 2000-2024. Arguments used to support bans often mischaracterize trophy hunting and its impacts and fail to recognize the benefits it can, and does, have for wildlife and people. Countries that have enacted or are considering import bans account for 64% of global trade in hunting trophies of CITES-listed species taken from the wild. Combined, these policies would restrict approximately one-fifth of this trade, likely with significant implications for conservation. We question whether these legislative actions are proportionate and discuss policy solutions. Wildlife trade solutions may appear simple, but evidence-based, just policies are needed to conserve biodiversity and avoid harming people.

ecology↗

bioRxiv2024

Synergy between Group 2 capsules and lipopolysaccharide underpins serum resistance in Extra-intestinal Pathogenic Escherichia coli

Escherichia coli (E. coli) is a major cause of urinary tract infections, bacteraemia, and sepsis. CFT073 is a prototypic, urosepsis isolate of sequence type (ST) 73. This laboratory, among others, has shown that strain CFT073 is resistant to serum, with capsule and other extracellular polysaccharides imparting resistance. The interplay of such polysaccharides remains under-explored. This study has shown that CFT073 mutants deficient in lipopolysaccharide (LPS) O-antigen and capsule display exquisite serum sensitivity. Additionally, O-antigen and LPS outer core mutants displayed significantly reduced surface K2 capsule, coupled with increased unbound K2 capsule being detected in the supernatant. The R1 core and O6 antigen are involved in the tethering of K2 capsule to the CFT073 cell surface, highlighting the importance of the R1 core in serum resistance. The dependence of capsule on LPS was shown to be post-transcriptional and related to changes in cell surface charge. Furthermore, immunofluorescence microscopy suggested that the surface pattern of capsule is altered in such LPS core mutants, which display a punctate capsule expression. Finally, targeting LPS biosynthesis using sub-inhibitory concentrations of a WaaG inhibitor resulted in increased serum sensitivity, antibiotic sensitivity, and reduced capsule in CFT073. Interestingly, the dependency of capsule on LPS has been observed previously in several Klebsiella pneumoniae isolates and a neonatal meningitic E. coli strain, indicating that the synergy between these polysaccharides is not just strain, serotype or species-specific but may be conserved across several pathogenic Gram-negative species. Therefore, using WaaG inhibitor derivatives or phage-derived depolymerases to target LPS is a promising avenue for co-administration with antibiotics to reduce morbidity and mortality by reducing or eliminating surface capsule. Impact statementDisseminated infections caused by E. coli place a large burden on healthcare systems globally, with incidence as well as antimicrobial resistance on the rise (1, 2). The key to designing successful therapeutic strategies is to understand how and why bacteria can cause infection, with an increased need for alternative/ preventative therapies in the age of antimicrobial resistance. ST131 is the predominant and most significant clonal group of bloodstream isolates currently (3-6). The second-most frequently isolated clonal group in E. coli bloodstream infections is that of ST73, into which the prototype used in this study, CFT073, is categorised (3, 5-7). Whilst antimicrobial resistance is not currently widespread in the ST73 clonal group, patterns of drug resistance are emerging (7). The clonal group is also associated with higher virulence scores than ST131, highlighting a need to better understand ST73 virulence to identify potential therapeutic intervention strategies (6). This study has identified a synergy between common virulence factors of sepsis-associated E. coli, capsule and LPS, which can be exploited to reduce virulence, a promising prospect in the age of antimicrobial resistance. Data summaryOligonucleotide primers for mutagenesis as well as schematic representations of gene clusters were designed based on the assembled genome sequence of strain CFT073 (GenBank accession number: AE014075.1). The authors confirm all other supporting data, code and protocols have been provided within the article or through supplementary data files.

microbiology↗

bioRxiv2023

Evaluating key evidence and formulating regulatory alternatives regarding the UK Hunting Trophies (Import Prohibition) Bill

Public policy addressing biodiversity loss is most likely to be effective when it is informed by appropriate evidence and considers potential unintended consequences. We evaluate key evidence relating to the Hunting Trophies (Import Prohibition) Bill that was discussed in the UK Parliament between 2022 and 2024. We characterize the UKs role in international hunting trophy trade by analyzing CITES trade data for 2000-2021 and 2015-2021. For CITES-listed species imported to/exported from the UK as hunting trophies in these periods we use data from the International Union for Conservation of Nature Red List of Threatened Species to determine whether hunting designated as "trophy hunting" is i) likely a major threat contributing to species being of elevated conservation concern, ii) likely or possibly causing localized declines, or iii) not a threat. We then use the Red List to determine whether such hunting provides, or potentially provides, benefits for species and/or people. Finally, we evaluate the UK Governments impact assessment of the bill. In 2000-2021 an estimated 3494 hunting trophies from 73 CITES-listed species and subspecies were exported to the UK involving an estimated 2549 whole organism equivalents (WOEs), i.e. individual animals. Imports involved 158.86 {+/-} 66.53 (mean {+/-} SD) trophies/year (115.83 {+/-} 32.27 WOEs/year). In 2015-2021, 79% of imports were from countries where populations of the hunted species are stable, increasing, or abundant. Legal hunting for trophies is not a major threat to any of the species or subspecies imported to the UK, but likely or possibly represents a local threat to some populations of nine species. This hunting does, or could potentially, benefit 20 species and subspecies, and people. Among other concerns, the impact assessment failed to adequately consider the costs and benefits to local communities in countries where such hunting occurs. Informed by these analyses we discuss alternative regulatory options.

ecology↗

bioRxiv2020

Preventing extinctions post-2020 requires recovery actions and transformative change

Stopping human-induced extinctions will require strong policy commitments that comprehensively address threats to species. In 2021, a new Global Biodiversity Framework will be agreed by the Convention on Biological Diversity. Here we investigate how the suggested targets could contribute to reducing threats to threatened vertebrates, invertebrates, and plants, and assess the importance of a proposed target to implement recovery actions for threatened species. We find that whilst many of the targets benefit species, extinction risk for over one third of threatened species would not be reduced sufficiently without a target on recovery actions, including ex situ conservation, reintroductions and other species-specific interventions. A median of 41 threatened species per country require such actions, and they are found in most countries of the world. To prevent future extinctions, policy commitments must include recovery actions for the most threatened species in addition to broader transformative change.

ecology↗

bioRxiv2020

Prevalence of sustainable and unsustainable use of wild species inferred from the IUCN Red List

Unsustainable exploitation of wild species represents a serious threat to biodiversity and to the livelihoods of local communities and indigenous peoples. However, managed, sustainable use has the potential to forestall extinctions, aid recovery, and meet human needs. Research to date has focused on unsustainable biological resource use with little consideration of sustainable use; we infer the current prevalence of both. We analyzed species-level data for 30,923 species from 13 taxonomic groups on the IUCN Red List. Our results demonstrate the broad taxonomic prevalence of use, with 40% of species (10,098 of 25,009 species from 10 data-sufficient taxonomic groups) documented as being used. The main purposes of use are pets, display animals and horticulture, and human consumption. Use often has an adverse impact on species extinction risk (we define this as biologically unsustainable): intentional use is currently contributing to elevated extinction risk for over a quarter of all threatened or Near Threatened (NT) species (2,752 - 2,848 of 9,753 species). Intentional use also threatens 16% of all species used (1,597 - 1,631 of 10,098). However, 72% of species that are used (7,291 of 10,098) are Least Concern (LC), of which nearly half (3,469) also have stable or improving population trends. The remainder of used species are not documented as threatened by biological resource use, including 172 threatened or NT species with stable or improving populations. Around a third of species that have use documented as a threat do not currently receive targeted species management actions to directly address this threat. We offer suggestions for improving use-related Red List data. Our findings on the prevalence of sustainable and unsustainable use, and variation across taxa, can inform international policymaking, including the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, the Convention on Biological Diversity, and the Convention on International Trade in Endangered Species.

ecology↗

bioRxiv2020

A Detailed View of KIR Haplotype Structures and Gene Families as Provided by a New Motif-based Multiple Sequence Alignment

Human chromosome 19q13.4 contains genes encoding killer-cell immunoglobulin-like receptors (KIR). Reported haplotype lengths range from 67 to 269 kilobases and contain 4 to 18 genes. The region has certain properties such as single nucleotide variation, structural variation, homology, and repetitive elements that make it hard to align accurately beyond single gene alleles. To the best of our knowledge, a multiple sequence alignment of KIR haplotypes has never been published or presented. Such an alignment would be useful to precisely define KIR haplotypes and loci, provide context for assigning alleles (especially fusion alleles) to genes, infer evolutionary history, impute alleles, interpret and predict co-expression, and generate markers. In order to extend the framework of KIR haplotype sequences in the human genome reference, 27 new sequences were generated including 24 haplotypes from 12 individuals of African American ancestry that were selected for genotypic diversity and novelty to the reference, to bring the total to 68 full length genomic KIR haplotype sequences. We leveraged these data and tools from our long-read KIR haplotype assembly algorithm to define and align KIR haplotypes at <5 kb resolution on average. We then used a standard alignment algorithm to refine that alignment down to single base resolution. This processing demonstrated that the high-level alignment recapitulates human-curated annotation of the human haplotypes as well as a chimpanzee haplotype. Further, assignments and alignments of gene alleles were consistent with their human curation in haplotype and allele databases. These results define KIR haplotypes as 14 loci containing 9 genes. The multiple sequence alignments have been applied in two software packages as probes to capture and annotate KIR haplotypes and as markers to genotype KIR from WGS.

bioinformatics↗

bioRxiv2020

Efficient Sequencing, Assembly, and Annotation of Human KIR Haplotypes

The homology, recombination, variation, and repetitive elements in the natural killer-cell immunoglobulin-like receptor (KIR) region has made full haplotype DNA interpretation impossible without physical separation of chromosomes. Here, we present a new approach using long-read sequencing to efficiently capture, sequence, and assemble diploid human KIR haplotypes. Sequences for capture probe design were derived from public full-length gene and haplotype sequences. IDT xGen(R) Lockdown probes were used to capture 2-8 kb of sheared DNA fragments followed by sequencing on a PacBio Sequel. The sequences were error corrected, binned, and then assembled using the Canu assembler. The assembly was evaluated on 16 individuals (8 African American and 8 Europeans) from whom ground truth was known via long-range sequencing on fosmid-isolated chromosomes. Using only 18 capture probes, the results show that the assemblies cover 97% of the GenBank reference, are 99.97% concordant, and it takes only 1.8 contigs to cover 75% of the reference. We also report the first assembly of diploid KIR haplotypes from long-read WGS, including the first sequencing of cB05[~]tB01, which pairs a KIR2DS2/KIR2DS3 fusion with the tB01 region. Our targeted hybridization probe capture and sequencing approach is the first of its kind to fully sequence and phase all diploid human KIR haplotypes, and it is efficient enough for population-scale studies and clinical use.

bioinformatics↗

bioRxiv2019

Predicting KIR Structural Haplotypes with Novel Sequence Signatures from Short-read Whole Genome Sequencing

The killer cell immunoglobulin-like receptor (KIR) proteins evolve to fight viruses and mediate the bodys reaction to pregnancy. These roles provide selection pressure for variation at both the structural/haplotype and base/allele levels. At the same time, the genes have evolved relatively recently by tandem duplication and therefore exhibit very high sequence similarity over thousands of bases. These variation-homology patterns make it impossible to interpret KIR haplotypes from abundant short-read genome sequencing data at population scale using existing methods. Here, we developed an efficient computational approach for in silico KIR probe interpretation (KPI) to accurately interpret individuals KIR genes and haplotype-pairs from KIR sequencing reads. We designed synthetic 25-base sequence probes by analyzing previously reported haplotype sequences, and we developed a bioinformatics pipeline to interpret the probes in the context of 16 KIR genes and 16 haplotype structures. We demonstrated its accuracy on a synthetic data set as well as a real whole genome sequences from 748 individuals from The Genome of the Netherlands (GoNL). The GoNL predictions were compared with predictions from SNP-based predictions. Our results show 100% accuracy rate for the synthetic tests and a 99.6% family-consistency rate in the GoNL tests. Agreement with the SNP-based calls on KIR genes ranges from 72-100% with a mean of 92%; most differences occur in genes KIR2DS2, KIR2DL2, KIR2DS3, and KIR2DL5 where KPI predicts presence and the SNP-based interpretation predicts absence. Overall, the evidence suggests that KPIs accuracy is 97% or greater for both KIR gene and haplotype-pair predictions, although the presence/absence genotyping leads to ambiguous haplotype-pair predictions with 16 reference KIR haplotype structures. KPI is free, open, and easily executable as a Nextflow workflow supported by a Docker environment at https://github.com/droeatumn/kpi.

bioinformatics↗

bioRxiv2017

Revealing Complete Complex KIR Haplotypes Phased By Long-Read Sequencing Technology

The killer cell immunoglobulin-like receptor (KIR) region of human chromosome 19 contains up to sixteen genes for natural killer (NK) cell receptors that recognize human leukocyte antigen (HLA)/peptide complexes and other ligands. The KIR proteins fulfill functional roles in infections, pregnancy, autoimmune diseases, and transplantation. However, their characterization remains a constant challenge. Not only are the genes highly homologous due to their recent evolution by tandem duplications, but the region is structurally dynamic due to frequent transposon-mediated recombination. A sequencing approach that precisely captures the complexity of KIR haplotypes for functional annotation is desirable.\n\nWe present a unique approach to haplotype the KIR loci using Single Molecule, Real-Time (SMRT(R)) Sequencing. Using this method, we have - for the first time - comprehensively sequenced and phased sixteen KIR haplotypes from eight individuals without imputation. The information revealed four novel haplotype structures, a novel gene-fusion allele, novel and confirmed insertion/deletion events, a homozygous individual, and overall diversity for the structural haplotypes and their alleles.\n\nThese KIR haplotypes augment our existing knowledge by providing high-quality references, evolutionary informers, and source material for imputation. The haplotype sequences and gene annotations provide alternative loci for the KIR region in the human genome reference GrCh38.p8.\n\nAuthor contributionsDR, CVG, SS, SR, DEG, MM designed the project. CWP, KE, RH performed the preparation and sequencing experiments. DR, CVG, RK, SR, DWG wrote the majority of the manuscript.

genomics↗