Linear Mixed Model of Virus Disinfection by Free Chlorine to Harmonize Data Collected across Broad Environmental Conditions.

Despite the critical importance of virus disinfection by chlorine, our fundamental understanding of the relative susceptibility of different viruses to chlorine and robust quantitative relationships between virus disinfection rate constants and environmental parameters remains limited. We conducted a systematic review of virus inactivation by free chlorine and used the resulting data set to develop a linear mixed model that estimates chlorine inactivation rate constants for viruses based on experimental conditions. 570 data points were collected in our systematic review, representing 82 viruses over a broad range of environmental conditions. The harmonized inactivation rate constants under reference conditions (pH = 7.53, T = 20 °C, [Cl-] < 50 mM) spanned 4 orders of magnitude, ranging from 0.0196 to 1150 L mg-1 min-1, and uncovered important trends between viruses. Whereas common surrogate bacteriophage MS2 does not serve as a conservative chlorine disinfection surrogate for many human viruses, CVB5 was one of the most resistant viruses in the data set. The model quantifies the role of pH, temperature, and chloride levels across viruses, and an online tool allows users to estimate rate constants for viruses and conditions of interest. Results from the model identified potential shortcomings in current U.S. EPA drinking water disinfection requirements.

The Easter Egg Weevil (Pachyrhynchus) genome reveals syntenic patterns in Coleoptera across 200 million years of evolution.

Patterns of genomic architecture across insects remain largely undocumented or decoupled from a broader phylogenetic context. For instance, it is unknown whether translocation rates differ between insect orders. We address broad scale patterns of genome architecture across Insecta by examining synteny in a phylogenetic framework from open-source insect genomes. To accomplish this, we add a chromosome level genome to a crucial lineage, Coleoptera. Our assembly of the Pachyrhynchus sulphureomaculatus genome is the first chromosome scale genome for the hyperdiverse Phytophaga lineage and currently the largest insect genome assembled to this scale. The genome is significantly larger than those of other weevils, and this increase in size is caused by repetitive elements. Our results also indicate that, among beetles, there are instances of long-lasting (>200 Ma) localization of genes to a particular chromosome with few translocation events. While some chromosomes have a paucity of translocations, intra-chromosomal synteny was almost absent, with gene order thoroughly shuffled along a chromosome. This large amount of reshuffling within chromosomes with few inter-chromosomal events contrasts with patterns seen in mammals in which the chromosomes tend to exchange larger blocks of material more readily. To place our findings in an evolutionary context, we compared syntenic patterns across Insecta in a phylogenetic framework. For the first time, we find that synteny decays at an exponential rate relative to phylogenetic distance. Additionally, there are significant differences in decay rates between insect orders, this pattern was not driven by Lepidoptera alone which has a substantially different rate.

Renal Dysfunction and Arrhythmia Association in Patients Receiving Milrinone After Cardiac Surgery.

OBJECTIVE: The altered pharmacokinetics of milrinone in renal impairment could result in an increased risk of cardiac arrhythmias. This study aimed to determine if there is an association between new-onset arrhythmias and renal impairment after cardiac surgery following milrinone administration. DESIGN: A retrospective cohort study. SETTING: A single-center tertiary care hospital. PARTICIPANTS: Adult patients who received a milrinone infusion in the intensive care unit (ICU) setting after coronary artery bypass graft, valvuloplasty, annuloplasty, or a combination of these surgeries from July 1, 2014 to July 1, 2021. Renal impairment was defined using a creatinine clearance <60 mL/min, calculated using the Cockcroft-Gault equation. INTERVENTIONS: Patients received a weight-based continuous intravenous infusion of milrinone. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the presence of new arrhythmias after the initial administration of a weight-based continuous intravenous infusion of milrinone postcardiac surgery. Of the 197 patients who met inclusion, there was no difference in the presence of new arrhythmias (42.9% v 40.3%, p = 0.76) or in the time to first new arrhythmia from milrinone initiation in those with renal impairment compared to those without renal impairment (29.1 hours v 33.3 hours, p = 0.54). Patients with renal impairment had a longer hospital stay than patients without renal impairment (17.5 days v 13.9 days, p = 0.016). Arrhythmia type, length of ICU stay, ICU mortality, and hospital mortality were not different between the cohorts. CONCLUSIONS: There was no association between new arrhythmias, milrinone, and renal impairment in patients postcardiac surgery.

Type 2 Diabetes Management, Control and Outcomes During the COVID-19 Pandemic in Older US Veterans: an Observational Study.

BACKGROUND: The COVID-19 pandemic required a change in outpatient care delivery models, including shifting from in-person to virtual visits, which may have impacted care of vulnerable patients. OBJECTIVE: To describe the changes in management, control, and outcomes in older people with type 2 diabetes (T2D) associated with the shift from in-person to virtual visits. DESIGN AND PARTICIPANTS: In veterans aged ≥ 65 years with T2D, we assessed the rates of visits (in person, virtual), A1c measurements, antidiabetic deintensification/intensification, ER visits and hospitalizations (for hypoglycemia, hyperglycemia, other causes), and A1c level, in March 2020 and April-November 2020 (pandemic period). We used negative binomial regression to assess change over time (reference: pre-pandemic period, July 2018 to February 2020), by baseline Charlson Comorbidity Index (CCI; > 2 vs. <= 2) and A1c level. KEY RESULTS: Among 740,602 veterans (mean age 74.2 [SD 6.6] years), there were 55% (95% CI 52-58%) fewer in-person visits, 821% (95% CI 793-856%) more virtual visits, 6% (95% CI 1-11%) fewer A1c measurements, and 14% (95% CI 10-17%) more treatment intensification during the pandemic, relative to baseline. Patients with CCI > 2 had a 14% (95% CI 12-16%) smaller relative increase in virtual visits than those with CCI <= 2. We observed a seasonality of A1c level and treatment modification, but no association of either with the pandemic. After a decrease at the beginning of the pandemic, there was a rebound in other-cause (but not hypo- and hyperglycemia-related) ER visits and hospitalizations from June to November 2020. CONCLUSION: Despite a shift to virtual visits and a decrease in A1c measurement during the pandemic, we observed no association with A1c level or short-term T2D-related outcomes, providing some reassurance about the adequacy of virtual visits. Further studies should assess the longer-term effects of shifting to virtual visits in different populations to help individualize care, improve efficiency, and maintain appropriate care while reducing overuse.

Genomic Characterization and Curation of UCEs Improves Species Tree Reconstruction.

Ultraconserved genomic elements (UCEs) are generally treated as independent loci in phylogenetic analyses. The identification pipeline for UCE probes does not require prior knowledge of genetic identity, only selecting loci that are highly conserved, single copy, without repeats, and of a particular length. Here, we characterized UCEs from 11 phylogenomic studies across the animal tree of life, from birds to marine invertebrates. We found that within vertebrate lineages, UCEs are mostly intronic and intergenic, while in invertebrates, the majority are in exons. We then curated four different sets of UCE markers by genomic category from five different studies including: birds, mammals, fish, Hymenoptera (ants, wasps, and bees), and Coleoptera (beetles). Of genes captured by UCEs, we find that many are represented by two or more UCEs, corresponding to nonoverlapping segments of a single gene. We considered these UCEs to be nonindependent, merged all UCEs that belonged to a particular gene, constructed gene and species trees, and then evaluated the subsequent effect of merging cogenic UCEs on gene and species tree reconstruction. Average bootstrap support for merged UCE gene trees was significantly improved across all data sets apparently driven by the increase in loci length. Additionally, we conducted simulations and found that gene trees generated from merged UCEs were more accurate than those generated by unmerged UCEs. As loci length improves gene tree accuracy, this modest degree of UCE characterization and curation impacts downstream analyses and demonstrates the advantages of incorporating basic genomic characterizations into phylogenomic analyses. [Anchored hybrid enrichment; ants; ASTRAL; bait capture; carangimorph; Coleoptera; conserved nonexonic elements; exon capture; gene tree; Hymenoptera; mammal; phylogenomic markers; songbird; species tree; ultraconserved elements; weevils.].

Association of tacrolimus time-to-therapeutic range on renal dysfunction and acute cellular rejection after orthotopic heart transplantation in a high use basiliximab population.

BACKGROUND: Currently, clinicians often delay initiation of tacrolimus after orthotopic heart transplantation (OHT) to help mitigate nephrotoxicity. This study aimed to determine if there is an association between the time-to-therapeutic range (TTT) of tacrolimus, early renal dysfunction, and acute cellular rejection (ACR) after OHT. METHODS: This was a retrospective, single center study with adult patients who underwent OHT from July 2013 to April 2020. Logistic regression analysis was utilized to examine the association of TTT with new renal dysfunction after tacrolimus initiation post-OHT. RESULTS: In a study of 317 patients, the unadjusted analysis showed patients who developed new renal dysfunction after tacrolimus initiation had a numerically shorter TTT (9.5 vs. 11.0 days, P = .065), and were more likely to have supratherapeutic tacrolimus levels (56% vs. 39.2%, P = .010). When adjusted for established risk factors for renal dysfunction, TTT was significantly associated with new renal dysfunction (OR .95; 95% CI [.90, .99], P = .03). There was no association between TTT and the incidence of ACR (11.1 vs. 10.8 days, P = .64). CONCLUSION: When adjusting for known risk factors, a shorter TTT was associated with new renal dysfunction. Supratherapeutic tacrolimus levels were also associated with new renal dysfunction. There was no association between TTT and ACR in the setting of high use basiliximab induction.

Predictive Modeling of Virus Inactivation by UV.

UV254 disinfection strategies are commonly applied to inactivate pathogenic viruses in water, food, air, and on surfaces. There is a need for methods that rapidly predict the kinetics of virus inactivation by UV254, particularly for emerging and difficult-to-culture viruses. We conducted a systematic literature review of inactivation rate constants for a wide range of viruses. Using these data and virus characteristics, we developed and evaluated linear and nonlinear models for predicting inactivation rate constants. Multiple linear regressions performed best for predicting the inactivation kinetics of (+) ssRNA and dsDNA viruses, with cross-validated root mean squared relative prediction errors similar to those associated with experimental rate constants. We tested the models by predicting and measuring inactivation rate constants of a (+) ssRNA mouse coronavirus and a dsDNA marine bacteriophage; the predicted rate constants were within 7% and 71% of the experimental rate constants, respectively, indicating that the prediction was more accurate for the (+) ssRNA virus than the dsDNA virus. Finally, we applied our models to predict the UV254 rate constants of several viruses for which high-quality UV254 inactivation data are not available. Our models will be valuable for predicting inactivation kinetics of emerging or difficult-to-culture viruses.

A phylogenomic analysis of turtles.

Molecular analyses of turtle relationships have overturned prevailing morphological hypotheses and prompted the development of a new taxonomy. Here we provide the first genome-scale analysis of turtle phylogeny. We sequenced 2381 ultraconserved element (UCE) loci representing a total of 1,718,154bp of aligned sequence. Our sampling includes 32 turtle taxa representing all 14 recognized turtle families and an additional six outgroups. Maximum likelihood, Bayesian, and species tree methods produce a single resolved phylogeny. This robust phylogeny shows that proposed phylogenetic names correspond to well-supported clades, and this topology is more consistent with the temporal appearance of clades and paleobiogeography. Future studies of turtle phylogeny using fossil turtles should use this topology as a scaffold for their morphological phylogenetic analyses.

High-Quality, Chromosome-Level Reference Genomes of the Viviparous Caribbean Skinks Spondylurus nitidus and S. culebrae.

New World mabuyine skinks are a diverse radiation of morphologically cryptic lizards with unique reproductive biologies. Recent studies examining population-level data (morphological, ecological, and genomic) have uncovered novel biodiversity and phenotypes, including the description of dozens of new species and insights into the evolution of their highly complex placental structures. Beyond the potential for this diverse group to serve as a model for the evolution of viviparity in lizards, much of the taxonomic diversity is concentrated in regions experiencing increasing environmental instability from climate and anthropogenic change. Consequently, a better understanding of genome structure and diversity will be an important tool in the adaptive management and conservation of this group. Skinks endemic to Caribbean islands are particularly vulnerable to global change with several species already considered likely extinct and several remaining species either endangered or threatened. Combining PacBio long-read sequencing, Hi-C, and RNAseq data, here we present the first genomic resources for this group by describing new chromosome-level reference genomes for the Puerto Rican Skink Spondylurus nitidus and the Culebra Skink S. culebrae. Results indicate two high quality genomes, both ∼1.4 Gb, assembled nearly telomere to telomere with complete mitochondrion assembly and annotation.

Genome Assembly of Pyrocephalus nanus: A Step Toward the Genetic Conservation of the Endangered Little Vermilion Flycatcher of the Galapagos Islands.

Incredibly powerful whole genome studies of conservation genetics, evolution, and biogeography become possible for non-model organisms when reference genomes are available. Here, we report the sequence and assembly of the whole genome of the little vermilion flycatcher (Pyrocephalus nanus; family Tyrannidae), which is an endemic, endangered, and declining species of the Galapagos Islands. Using PacBio HiFi reads to assemble long contigs and Hi-C reads for scaffolding, we assembled a genome of 1.07 Gb comprising 267 contigs in 152 scaffolds, scaffold N50 74 M, contig N50 17.8 M, with 98.9% assigned to candidate chromosomal sequences and 99.72% of the BUSCO passeriformes 10,844 single-copy orthologs present. In addition, we used the novel HiFiMiTie pipeline to fully assemble and verify all portions of the mitochondrial genome from HiFi reads, obtaining a mitogenome of 17,151 bases, containing 13 protein-coding genes, 22 tRNAs, 2 rRNAs, two control regions, and a unique structure of control region duplication and repeats. These genomes will be a critical tool for much-needed studies of phylogenetics, population genetics, biogeography, and conservation genetics of Pyrocephalus and related genera. This genome and other studies that use it will be able to provide recommendations for conservation management, taxonomic improvement, and to understand the evolution and diversification of this genus within the Galapagos Islands.

Comparative genomics of symbiotic Photobacterium using highly contiguous genome assemblies from long read sequences.

This study presents the assembly and comparative genomic analysis of luminous Photobacterium strains isolated from the light organs of 12 fish species using Oxford Nanopore Technologies (ONT) sequencing. The majority of assemblies achieved chromosome-level continuity, consisting of one large (>3 Mbp) and one small (~1.5 Mbp) contig, with near complete BUSCO scores along with varying plasmid sequences. Leveraging this dataset, this study significantly expanded the available genomes for P. leiognathi and its subspecies P. 'mandapamensis', enabling a comparative genomic analysis between the two lineages. An analysis of the large and small chromosomes unveiled distinct patterns of core and accessory genes, with a larger fraction of the core genes residing on the large chromosome, supporting the hypothesis of secondary chromosome evolution from megaplasmids in Vibrionaceae. In addition, we discovered a proposed new species, Photobacterium acropomis sp. nov., isolated from an acropomatid host, with an average nucleotide identify (ANI) of 93 % compared to the P. leiognathi and P. 'mandapamensis' strains. A comparison of the P. leiognathi and P. 'mandapamensis' lineages revealed minimal differences in gene content, yet highlighted the former's larger genome size and potential for horizontal gene transfer. An investigation of the lux-rib operon, responsible for light production, indicated congruence between the presence of luxF and host family, challenging its role in differentiating P. 'mandapamensis' from P. leiognathi. Further insights were derived from the identification of metabolic differences, such as the presence of the NADH:quinone oxidoreductase respiratory complex I in P. leiognathi as well as variations in the type II secretion system (T2S) genes between the lineages, potentially impacting protein secretion and symbiosis. In summary, this study advances our understanding of Photobacterium genome evolution, highlighting subtle differences between closely related lineages, specifically P. leiognathi and P. 'mandapamensis'. These findings highlight the benefit of long read sequencing for bacterial genome assembly and pangenome analysis and provide a foundation for exploring early bacterial speciation processes of these facultative light organ symbionts.

Impact of Thrombocytopenia on Postoperative Bleeding Incidence in Patients Receiving Aspirin Following Coronary Artery Bypass Grafting.

BACKGROUND: Early postoperative aspirin following coronary artery bypass graft (CABG) surgery has been shown to maintain bypass graft patency, reduce mortality, and prevent adverse cardiovascular events. Despite this known benefit, aspirin may be delayed due to thrombocytopenia and perceived higher bleeding risk. The purpose of this study was to assess the impact of postoperative platelet count on bleeding in patients receiving aspirin after CABG. METHODS: A retrospective analysis included all patients who underwent CABG surgery at our institution from April 2014 to June 2018 and received aspirin within 24 hours. The primary outcome was International Society on Thrombosis and Hemostasis (ISTH) major bleeding within 7 days (or up to discharge) following CABG surgery compared between patients with and without postoperative thrombocytopenia. RESULTS: This study included 280 patients. Major bleeding occurred in 24.6% of the population, with no difference when stratified by the presence or absence of postoperative thrombocytopenia (27.3% versus 23.8%, p = 0.571). There was no significant difference in hemoglobin fall (13.6% versus 14%, p = 0.948), transfusion requirement (6.1% versus 4.2%, p = 0.531), or critical site bleeding (12.1% versus 7.9%, p = 0.298). CONCLUSION: In this single-center analysis of patients who received aspirin within 24 hours of CABG, postoperative thrombocytopenia was not associated with an increase in bleeding.

Trio-binned genomes of the woodrats Neotoma bryanti and Neotoma lepida reveal novel gene islands and rapid copy number evolution of xenobiotic metabolizing genes.

The genomic architecture underlying the origins and maintenance of biodiversity is an increasingly accessible feature of species, due in large part to third-generation sequencing and novel analytical toolsets. Applying these techniques to woodrats (Neotoma spp.) provides a unique opportunity to study how herbivores respond to environmental change. Neotoma bryanti and N. lepida independently achieved a major dietary feat in the aftermath of a natural climate change event: switching to the novel, toxic food source creosote bush (Larrea tridentata). To better understand the genetic mechanisms underlying this ability, we employed a trio binning sequencing approach with a N. bryanti × N. lepida F1 hybrid, allowing the simultaneous assembly of genomes representing each parental species. The resulting phased, chromosome-level, highly complete haploid references enabled us to explore the genomic architecture of several gene families-cytochromes P450, UDP-glucuronosyltransferases (UGTs), and ATP-binding cassette (ABC) transporters-known to play key roles in the metabolism of naturally occurring toxic dietary compounds. In addition to duplication events in the ABCG and UGT2B subfamilies, we found expansions in three P450 gene families (2A, 2B, 3A), including the evolution of multiple novel gene islands within the 2B and 3A subfamilies, which may have provided the crucial substrate for dietary adaptation. Our assemblies demonstrate that trio binning from an F1 hybrid rodent effectively recovers parental genomes from species that diverged more than a million years ago.

An Annotated Chromosome-Level Reference Genome of the Red-Eared Slider Turtle (Trachemys scripta elegans).

Among vertebrates, turtles have many unique characteristics providing biologists with opportunities to study novel evolutionary innovations and processes. We present here a high-quality, partially phased, and chromosome-level Red-Eared Slider (Trachemys scripta elegans, TSE) genome as a reference for future research on turtle and tetrapod evolution. This TSE assembly is 2.269 Gb in length, has one of the highest scaffold N50 and N90 values of any published turtle genome to date (N50 = 129.68 Mb and N90 = 19 Mb), and has a total of 28,415 annotated genes. We introduce synteny analyses using BUSCO single-copy orthologs, which reveal two chromosome fusion events accounting for differences in chromosome counts between emydids and other cryptodire turtles and reveal many fission/fusion events for birds, crocodiles, and snakes relative to TSE. This annotated chromosome-level genome will provide an important reference genome for future studies on turtle, vertebrate, and chromosome evolution.

Incidence of and Risk Factors for Hepatic Encephalopathy in a Population-Based Cohort of Americans With Cirrhosis.

Hepatic encephalopathy (HE) is a devastating complication of cirrhosis. Data are limited regarding the incidence of and risk factors for HE among contemporary patients in the context of the shifting epidemiology of cirrhosis. We examined a 20% random sample of U.S. Medicare enrollees with cirrhosis and Part D prescription coverage from 2008 to 2014. We modelled incident HE using demographic, clinical, and pharmacologic data. Risk factors for HE were evaluated, including demographics/socioeconomics, cirrhosis etiology, severity of liver disease, and pharmacotherapy, along with gastroenterology consultation, as time-varying covariates. Among 166,192 Medicare enrollees with cirrhosis followed for 5.25 (interquartile range [IQR], 2.00-7.00) years, the overall incidence of HE was 11.6 per 100 patient-years. The cohort's median age was 65 years (IQR, 57-72), 31% had alcohol-related cirrhosis, and 49% had likely nonalcoholic fatty liver disease cirrhosis. The two strongest associations with HE were alcohol-related cirrhosis (adjusted hazard ratio [AHR], 1.44; 95% confidence interval [CI], 1.40, 1.47, relative to nonalcoholic nonviral cirrhosis) and the presence of portal hypertension (AHR, 3.42; 95% CI, 3.34, 3.50). Adjusting for confounders, benzodiazepines (AHR, 1.24; 95% CI, 1.21, 1.27), gamma aminobutyric acid (GABA)ergics (AHR, 1.17; 95% CI, 1.14, 1.21), opioids (AHR, 1.24; 95% CI, 1.21, 1.27), and proton pump inhibitors (PPIs) (AHR, 1.41; 95% CI, 1.38, 1.45) were all associated with incident HE. Only benzodiazepines, however, were associated with the risk of hospitalization with HE (incidence-rate ratio, 1.23; 95% CI, 1.20, 1.26). Conclusion: Novel data regarding the risk of HE for contemporary patients with cirrhosis are provided. The incidence of HE in an older population of Americans with cirrhosis is high, particularly among those with alcohol-related cirrhosis and portal hypertension. Several medication classes, namely PPIs, opiates, GABAergics, and benzodiazepines, represent potentially modifiable risk factors for HE.

Predictors of Warfarin Time in Therapeutic Range after Continuous-Flow Left Ventricular Assist Device.

INTRODUCTION: Patients with a continuous-flow left ventricular assist device (CF-LVAD) require anticoagulation with a vitamin K antagonist to prevent thromboembolic events. Fluctuations in the international normalized ratio are associated with both increased thrombotic and bleeding episodes. To date, risk factors for low time in therapeutic range (TTR) among ambulatory patients with a CF-LVAD have not been explored. METHODS: A retrospective single-center analysis of 121 patients implanted with a CF-LVAD was performed. International normalized ratios were systematically recorded from the initial postdischarge outpatient visit to 12 months of time on the device. Risk factors for low TTR were evaluated using a multivariable linear regression analysis. Each of the 21 independent variables was entered into a stepwise regression designed to minimize the Akaike information criteria. RESULTS: In the multivariable analysis, the model output revealed that every 1-year increase in age was associated with a 0.4% increase in TTR (p=0.008), and every 1 mile further from clinic was associated with a 0.08% increase in TTR (p=0.03). Female sex was associated with a 10.1% decrease in TTR (p=0.04), type 2 diabetes was associated with an 11.5% decrease in TTR (p=0.006), and prior warfarin use was associated with an 8.3% decrease in TTR (p=0.03). CONCLUSION: In CF-LVAD recipients receiving warfarin, increasing age and distance from clinic are independent predictors of higher TTR. Female sex, type 2 diabetes, and prior warfarin use are independent predictors of lower TTR.

Nanopore sequencing of long ribosomal DNA amplicons enables portable and simple biodiversity assessments with high phylogenetic resolution across broad taxonomic scale.

BACKGROUND: In light of the current biodiversity crisis, DNA barcoding is developing into an essential tool to quantify state shifts in global ecosystems. Current barcoding protocols often rely on short amplicon sequences, which yield accurate identification of biological entities in a community but provide limited phylogenetic resolution across broad taxonomic scales. However, the phylogenetic structure of communities is an essential component of biodiversity. Consequently, a barcoding approach is required that unites robust taxonomic assignment power and high phylogenetic utility. A possible solution is offered by sequencing long ribosomal DNA (rDNA) amplicons on the MinION platform (Oxford Nanopore Technologies). FINDINGS: Using a dataset of various animal and plant species, with a focus on arthropods, we assemble a pipeline for long rDNA barcode analysis and introduce a new software (MiniBar) to demultiplex dual indexed Nanopore reads. We find excellent phylogenetic and taxonomic resolution offered by long rDNA sequences across broad taxonomic scales. We highlight the simplicity of our approach by field barcoding with a miniaturized, mobile laboratory in a remote rainforest. We also test the utility of long rDNA amplicons for analysis of community diversity through metabarcoding and find that they recover highly skewed diversity estimates. CONCLUSIONS: Sequencing dual indexed, long rDNA amplicons on the MinION platform is a straightforward, cost-effective, portable, and universal approach for eukaryote DNA barcoding. Although bulk community analyses using long-amplicon approaches may introduce biases, the long rDNA amplicons approach signifies a powerful tool for enabling the accurate recovery of taxonomic and phylogenetic diversity across biological communities.

Whole-genome assembly of the coral reef Pearlscale Pygmy Angelfish (Centropyge vrolikii).

The diversity of DNA sequencing methods and algorithms for genome assemblies presents scientists with a bewildering array of choices. Here, we construct and compare eight candidate assemblies combining overlapping shotgun read data, mate-pair and Chicago libraries and four different genome assemblers to produce a high-quality draft genome of the iconic coral reef Pearlscale Pygmy Angelfish, Centropyge vrolikii (family Pomacanthidae). The best candidate assembly combined all four data types and had a scaffold N50 127.5 times higher than the candidate assembly obtained from shotgun data only. Our best candidate assembly had a scaffold N50 of 8.97 Mb, contig N50 of 189,827, and 97.4% complete for BUSCO v2 (Actinopterygii set) and 95.6% complete for CEGMA matches. These contiguity and accuracy scores are higher than those of any other fish assembly released to date that did not apply linkage map information, including those based on more expensive long-read sequencing data. Our analysis of how different data types improve assembly quality will help others choose the most appropriate de novo genome sequencing strategy based on resources and target applications. Furthermore, the draft genome of the Pearlscale Pygmy angelfish will play an important role in future studies of coral reef fish evolution, diversity and conservation.

Whole-Genome Analysis of Introgression Between the Spotted Owl and Barred Owl (Strix occidentalis and Strix varia, Respectively; Aves: Strigidae) in Western North America.

As the barred owl (Strix varia; Aves: Strigiformes: Strigidae) expands throughout western North America, hybridization between barred and spotted owls (Strix varia and S. occidentalis, respectively), if abundant, may lead to genetic swamping of the endangered spotted owl. We analyzed low-coverage, whole-genome sequence data from fifty-one barred and spotted owls to investigate recent introgression between these two species. Although we obtained genomic confirmation that these species can and do hybridize and backcross, we found no evidence of widespread introgression. Plumage characteristics of western S. varia that suggested admixture with S. occidentalis appear unrelated to S. occidentalis ancestry and may instead reflect local selection.