Protein G-quadruplex interactions and their effects on phase transitions and protein aggregation.

The SERF family of proteins were originally discovered for their ability to accelerate amyloid formation. Znf706 is an uncharacterized protein whose N-terminus is homologous to SERF proteins. We show here that human Znf706 can promote protein aggregation and amyloid formation. Unexpectedly, Znf706 specifically interacts with stable, non-canonical nucleic acid structures known as G-quadruplexes. G-quadruplexes can affect gene regulation and suppress protein aggregation; however, it is unknown if and how these two activities are linked. We find Znf706 binds preferentially to parallel G-quadruplexes with low micromolar affinity, primarily using its N-terminus, and upon interaction, its dynamics are constrained. G-quadruplex binding suppresses Znf706's ability to promote protein aggregation. Znf706 in conjunction with G-quadruplexes therefore may play a role in regulating protein folding. RNAseq analysis shows that Znf706 depletion specifically impacts the mRNA abundance of genes that are predicted to contain high G-quadruplex density. Our studies give insight into how proteins and G-quadruplexes interact, and how these interactions affect both partners and lead to the modulation of protein aggregation and cellular mRNA levels. These observations suggest that the SERF family of proteins, in conjunction with G-quadruplexes, may have a broader role in regulating protein folding and gene expression than previously appreciated.

Evolutionary rate covariation is a reliable predictor of co-functional interactions but not necessarily physical interactions.

Co-functional proteins tend to have rates of evolution that covary over time. This correlation between evolutionary rates can be measured over the branches of a phylogenetic tree through methods such as evolutionary rate covariation (ERC), and then used to construct gene networks by the identification of proteins with functional interactions. The cause of this correlation has been hypothesized to result from both compensatory coevolution at physical interfaces and nonphysical forces such as shared changes in selective pressure. This study explores whether coevolution due to compensatory mutations has a measurable effect on the ERC signal. We examined the difference in ERC signal between physically interacting protein domains within complexes compared to domains of the same proteins that do not physically interact. We found no generalizable relationship between physical interaction and high ERC, although a few complexes ranked physical interactions higher than nonphysical interactions. Therefore, we conclude that coevolution due to physical interaction is weak, but present in the signal captured by ERC, and we hypothesize that the stronger signal instead comes from selective pressures on the protein as a whole and maintenance of the general function.

Vocal learning-associated convergent evolution in mammalian proteins and regulatory elements.

Vocal production learning ("vocal learning") is a convergently evolved trait in vertebrates. To identify brain genomic elements associated with mammalian vocal learning, we integrated genomic, anatomical, and neurophysiological data from the Egyptian fruit bat (Rousettus aegyptiacus) with analyses of the genomes of 215 placental mammals. First, we identified a set of proteins evolving more slowly in vocal learners. Then, we discovered a vocal motor cortical region in the Egyptian fruit bat, an emergent vocal learner, and leveraged that knowledge to identify active cis-regulatory elements in the motor cortex of vocal learners. Machine learning methods applied to motor cortex open chromatin revealed 50 enhancers robustly associated with vocal learning whose activity tended to be lower in vocal learners. Our research implicates convergent losses of motor cortex regulatory elements in mammalian vocal learning evolution.

Protein G-quadruplex interactions and their effects on phase transitions and protein aggregation.

The SERF family of proteins were originally discovered for their ability to accelerate amyloid formation. Znf706 is an uncharacterized protein whose N-terminus is homologous to SERF proteins. We show here that human Znf706 can promote protein aggregation and amyloid formation. Unexpectedly, Znf706 specifically interacts with stable, non-canonical nucleic acid structures known as G-quadruplexes. G-quadruplexes can affect gene regulation and suppress protein aggregation; however, it is unknown if and how these two activities are linked. We find Znf706 binds preferentially to parallel G-quadruplexes with low micromolar affinity, primarily using its N-terminus, and upon interaction, its dynamics are constrained. G-quadruplex binding suppresses Znf706's ability to promote protein aggregation. Znf706 in conjunction with G-quadruplexes therefore may play a role in regulating protein folding. RNAseq analysis shows that Znf706 depletion specifically impacts the mRNA abundance of genes that are predicted to contain high G-quadruplex density. Our studies give insight into how proteins and G-quadruplexes interact, and how these interactions affect both partners and lead to the modulation of protein aggregation and cellular mRNA levels. These observations suggest that the SERF family of proteins, in conjunction with G-quadruplexes, may have a broader role in regulating protein folding and gene expression than previously appreciated.

Use of Peripheral Intravenous Access in Patients Undergoing Chemotherapy for Testicular Cancer.

PURPOSE: Systemic chemotherapy, depending on the regimen, can be administered through peripheral intravenous (pIV) access or through central venous access devices (CVADs). There is no current best practice regarding optimal access for chemotherapy for patients with testicular cancer (TC). We retrospectively evaluated patients undergoing systemic chemotherapy for TC and compared baseline characteristics and complications of patients using pIV versus CVADs. METHODS: We included patients with TC who underwent first-line systemic chemotherapy at the University of Colorado Hospitals from 2005 to 2020. Data were collected on demographics, cancer characteristics, type, duration of chemotherapy, pIV or CVAD use, and associated complication rates. We then performed univariate and multivariate regression analyses to compare complication rates and risk factors for each group. RESULTS: One hundred fifty-four patients met inclusion criteria. Ninety-two (60%) patients used CVADs, and 62 patients (40%) used pIV for their initial treatment. Only six (9.7%) of 62 patients transitioned from pIV to CVADs during therapy. Similarly, 10 of 92 (10.9%) patients with initial CVAD needed to transition to a different type of CVAD or to pIV (P = .81). There were a greater number of venous access-related complications (48 of 92 patients, 52.2%) and overall thrombotic events (33 of 92 patients, 35.9%) for the CVAD group (P > .001) when compared with the pIV group. We observed an association between the following factors and venous access-related complications during chemotherapy: higher stage TC, increased total chemotherapy cycles, and delayed therapy. CONCLUSION: Peripheral IV use for first-line nonvesicant chemotherapy in patients with TC appears to be well tolerated with high rates of therapy completion and lower rates of complications when compared with CVADs. These data support our preferred treatment approach and provide evidence that pIV access is a safe and effective way to deliver chemotherapy for patients with TC.

Sociodemographic and health-related differences in undiagnosed hypertension in the health survey for England 2015-2019: a cross-sectional cohort study.

Background: Hypertension is a leading cause of morbidity and mortality worldwide, yet a substantial proportion of cases are undiagnosed. Understanding the scale of undiagnosed hypertension and identifying groups most at risk is important to inform approaches to detection. Methods: In this cross-sectional cohort study, we used data from the 2015 to 2019 Health Survey for England, an annual, cross-sectional, nationally representative survey. The survey follows a multi-stage stratified probability sampling design, involving a random sample of primary sampling units based on postcode sectors, followed by a random sample of postal addresses within these units. Within each selected household, all adults (aged ≥16 years) and up to four children, were eligible for participation. For the current study, individuals aged 16 years and over who were not pregnant and had valid blood pressure data were included in the analysis. The primary outcome was undiagnosed hypertension, defined by a measured blood pressure of 140/90 mmHg or above but no history of diagnosis. Age-adjusted prevalence of undiagnosed hypertension was estimated across sociodemographic and health-related characteristics, including ethnicity, region, rural-urban classification, relationship status, highest educational qualification, National Statistics Socio-Economic Classification (NS-SEC), Body Mass Index (BMI), self-reported general health, and smoking status. To assess the independent association between undiagnosed hypertension and each characteristic, we fitted a logistic regression model adjusted for sociodemographic factors. Findings: The sample included 21,476 individuals, of whom 55.8% were female and 89.3% reported a White ethnic background. An estimated 30.7% (95% confidence interval 29.0-32.4) of men with hypertension and 27.6% (26.1-29.1) of women with hypertension were undiagnosed. Younger age, lower BMI, and better self-reported general health were associated with an increased likelihood of hypertension being undiagnosed for men and women. Living in rural areas and in regions outside of London and the East of England were also associated with an increased likelihood of hypertension being undiagnosed for men, as were being married or in a civil partnership and having higher educational qualifications for women. Interpretation: Hypertension is commonly undiagnosed, and some of the groups that are at the lowest risk of hypertension are the most likely to be undiagnosed. Given the high lifetime risk of hypertension and its strong links with morbidity and mortality, our findings suggest a need for greater awareness of the potential for undiagnosed hypertension, including among those typically considered 'low risk'. Further research is needed to assess the impact of extending hypertension screening to lower-risk groups. Funding: None.

RERconverge Expansion: Using Relative Evolutionary Rates to Study Complex Categorical Trait Evolution.

Comparative genomics approaches seek to associate evolutionary genetic changes with the evolution of phenotypes across a phylogeny. Many of these methods, including our evolutionary rates based method, RERconverge, lack the capability of analyzing non-ordinal, multicategorical traits. To address this limitation, we introduce an expansion to RERconverge that associates shifts in evolutionary rates with the convergent evolution of multi-categorical traits. The categorical RERconverge expansion includes methods for performing categorical ancestral state reconstruction, statistical tests for associating relative evolutionary rates with categorical variables, and a new method for performing phylogenetic permulations on multi-categorical traits. In addition to demonstrating our new method on a three-category diet phenotype, we compare its performance to naive pairwise binary RERconverge analyses and two existing methods for comparative genomic analyses of categorical traits: phylogenetic simulations and a phylogenetic signal based method. We also present a diagnostic analysis of the new permulations approach demonstrating how the method scales with the number of species and the number of categories included in the analysis. Our results show that our new categorical method outperforms phylogenetic simulations at identifying genes and enriched pathways significantly associated with the diet phenotype and that the new ancestral reconstruction drives an improvement in our ability to capture diet-related enriched pathways. Our categorical permulations were able to account for non-uniform null distributions and correct for non-independence in gene rank during pathway enrichment analysis. The categorical expansion to RERconverge will provide a strong foundation for applying the comparative method to categorical traits on larger data sets with more species and more complex trait evolution.

Molecular evolution of male reproduction across species with highly divergent sperm morphology in diverse murine rodents.

Sperm competition can drive rapid evolution of male reproductive traits, but it remains unclear how variation in sperm competition intensity shapes phenotypic and molecular diversity across clades. Old World mice and rats (subfamily Murinae) comprise a rapid radiation and exhibit incredible diversity in sperm morphology and production. We combined phenotype and sequence data to model the evolution of reproductive traits and genes across 78 murine species. We identified several shifts towards smaller relative testes mass, a trait reflective of reduced sperm competition. Several sperm traits were associated with relative testes mass, suggesting that mating system evolution likely selects for convergent traits related to sperm competitive ability. Molecular evolutionary rates of spermatogenesis proteins also correlated with relative testes mass, but in an unexpected direction. We predicted that sperm competition would result in rapid divergence among species with large relative testes mass, but instead found that many spermatogenesis genes evolve more rapidly in species with smaller relative testes mass due to relaxed purifying selection. While some reproductive genes evolved under positive selection, relaxed selection played a greater role underlying rapid evolution in small testes species. Our work demonstrates that sexual selection can impose strong purifying selection shaping the evolution of male reproduction.

Association of Direct Oral Anticoagulation Management Strategies With Clinical Outcomes for Adults With Atrial Fibrillation.

Importance: Anticoagulation management services (AMSs; ie, warfarin clinics) have evolved to include patients treated with direct oral anticoagulants (DOACs), but it is unknown whether DOAC therapy management services improve outcomes for patients with atrial fibrillation (AF). Objective: To compare outcomes associated with 3 DOAC care models for preventing adverse anticoagulation-related outcomes among patients with AF. Design, Setting, and Participants: This retrospective cohort study included 44 746 adult patients with a diagnosis of AF who initiated oral anticoagulation (DOAC or warfarin) between August 1, 2016, and December 31, 2019, in 3 Kaiser Permanente (KP) regions. Statistical analysis was conducted from August 2021 through May 2023. Exposures: Each KP region used an AMS to manage warfarin but used distinct approaches to DOAC care: (1) usual care (UC) by the prescribing clinician, (2) UC plus an automated population management tool (PMT), or (3) pharmacist-managed AMS care. Propensity scores and inverse probability of treatment weights (IPTWs) were estimated. Direct oral anticoagulant care models were first indirectly compared using warfarin as a common comparator within each region and then directly compared across regions. Main Outcomes and Measures: Patients were followed up until the first occurrence of an outcome (composite of thromboembolic stroke, intracranial hemorrhage, other major bleeding, or death), discontinuation of KP membership, or December 31, 2020. Results: Overall, 44 746 patients were included: 6182 in the UC care model (3297 DOAC; 2885 warfarin), 33 625 in the UC plus PMT care model (21 891 DOAC; 11 734 warfarin), and 4939 in the AMS care model (2089 DOAC; 2850 warfarin). Baseline characteristics (mean [SD] age, 73.1 [10.6] years, 56.1% male, 67.2% non-Hispanic White, median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes, stroke, vascular disease, age 65-74 years, female sex] score of 3 [IQR, 2-5]) were well balanced after IPTW. Over a median follow-up of 2 years, patients who received the UC plus PMT or AMS care model did not have significantly better outcomes than those who received UC. The incidence rate of the composite outcome was 5.4% per year for DOAC and 9.1% per year for warfarin for those in the UC group, 6.1% per year for DOAC and 10.5% per year for those in the UC plus PMT group, and 5.1% per year for DOAC and 8.0% per year for those in the AMS group. The IPTW-adjusted hazard ratios (HRs) for the composite outcome comparing DOAC vs warfarin were 0.91 (95% CI, 0.79-1.05) in the UC group, 0.85 (95% CI, 0.79-0.90) in the UC plus PMT group, and 0.84 (95% CI, 0.72-0.99) in the AMS group (P = .62 for heterogeneity across care models). When directly comparing patients receiving DOAC, the IPTW-adjusted HR was 1.06 (95% CI, 0.85-1.34) for the UC plus PMT group vs the UC group and 0.85 (95% CI, 0.71-1.02) for the AMS group vs the UC group. Conclusions and Relevance: This cohort study did not find appreciably better outcomes for patients receiving DOAC who were managed by either a UC plus PMT or AMS care model compared with UC.

Gadusol is a maternally provided sunscreen that protects fish embryos from DNA damage.

Exposure to ultraviolet radiation (UVR) is harmful to living cells, leading organisms to evolve protective mechanisms against UVR-induced cellular damage and stress.1,2 UVR, particularly UVB (280-320 nm), can damage proteins and DNA, leading to errors during DNA repair and replication. Excessive UVR can induce cellular death. Aquatic organisms face risk of UV exposure as biologically harmful levels of UVB can penetrate >10 m in clear water.3 While melanin is the only known sunscreen in vertebrates, it often emerges late in embryonic development, rendering embryos of many species vulnerable during the earlier stages. Algae and microbes produce a class of sunscreening compounds known as mycosporine-like amino acids (MAAs).4 Fish eggs contain a similar compound called gadusol, whose role as a sunscreen has yet to be tested despite its discovery over 40 years ago.5 The recent finding that many vertebrate genomes contain a biosynthetic pathway for gadusol suggests that many fish may produce and use this molecule as a sunscreen.6 We generated a gadusol-deficient mutant zebrafish to investigate the role of gadusol in protecting fish embryos and larvae from UVR. Our results demonstrate that maternally provided gadusol is the primary sunscreen in embryonic and larval development, while melanin provides modest secondary protection. The gadusol biosynthetic pathway is retained in the vast majority of teleost genomes but is repeatedly lost in species whose young are no longer exposed to UVR. Our data demonstrate that gadusol is a maternally provided sunscreen that is critical for early-life survival in the most species-rich branch of the vertebrate phylogeny.

Reduction of Paraoxonase Expression Followed by Inactivation across Independent Semiaquatic Mammals Suggests Stepwise Path to Pseudogenization.

Convergent adaptation to the same environment by multiple lineages frequently involves rapid evolutionary change at the same genes, implicating these genes as important for environmental adaptation. Such adaptive molecular changes may yield either change or loss of protein function; loss of function can eliminate newly deleterious proteins or reduce energy necessary for protein production. We previously found a striking case of recurrent pseudogenization of the Paraoxonase 1 (Pon1) gene among aquatic mammal lineages-Pon1 became a pseudogene with genetic lesions, such as stop codons and frameshifts, at least four times independently in aquatic and semiaquatic mammals. Here, we assess the landscape and pace of pseudogenization by studying Pon1 sequences, expression levels, and enzymatic activity across four aquatic and semiaquatic mammal lineages: pinnipeds, cetaceans, otters, and beavers. We observe in beavers and pinnipeds an unexpected reduction in expression of Pon3, a paralog with similar expression patterns but different substrate preferences. Ultimately, in all lineages with aquatic/semiaquatic members, we find that preceding any coding-level pseudogenization events in Pon1, there is a drastic decrease in expression, followed by relaxed selection, thus allowing accumulation of disrupting mutations. The recurrent loss of Pon1 function in aquatic/semiaquatic lineages is consistent with a benefit to Pon1 functional loss in aquatic environments. Accordingly, we examine diving and dietary traits across pinniped species as potential driving forces of Pon1 functional loss. We find that loss is best associated with diving activity and likely results from changes in selective pressures associated with hypoxia and hypoxia-induced inflammation.

The Impact of Clinical Pharmacy Services on Direct Oral Anticoagulant Medication Selection and Dosing in the Ambulatory Care Setting.

Background: Off-label dosing of direct oral anticoagulants (DOACs) is both common and associated with adverse patient outcomes. Evidence describing best practices to support optimal direct oral anticoagulant (DOAC) dosing is limited. Objective: To describe the impact of clinical pharmacist intervention on DOAC prescribing. Methods: This retrospective study was a descriptive analysis conducted within an integrated healthcare system with a centralized, pharmacist-led Anticoagulation Management Service (AMS). Patients prescribed a DOAC between January 1, 2020 and December 31, 2020 were included. Pharmacy dispensing reports were generated for pharmacist review and anticoagulant drug therapy changes were recommended to physicians where appropriate. The primary objective was to describe the number and type of recommendations made. Secondary objectives were to determine the provider acceptance rate based on the intervention type and on clinical vs formulary recommendations. Results: Clinical pharmacists made 147 recommendations for 2331 unique patients included in the analysis. Twenty-three recommendations (16%) were to decrease the dose, 46 (31%) were to increase the dose, 14 (10%) were to change the medication due to clinical scenario, 62 (42%) were to change the medication due to cost, and 2 (1%) were another issue. One hundred twenty-three (84%) recommendations were accepted. The provider acceptance rate was similar for clinical and formulary recommendations (85% and 82% respectively). Conclusion: Implementation of report-driven clinical pharmacist intervention led to an improvement in appropriate DOAC medication selection and dosing.

Gadusol is a maternally provided sunscreen that protects fish embryos from DNA damage.

Ultraviolet radiation (UVR) and its deleterious effects on living cells selects for UVR-protective mechanisms. Organisms across the tree of life evolved a variety of natural sunscreens to prevent UVR-induced cellular damage and stress. However, in vertebrates, only melanin is known to act as a sunscreen. Here we demonstrate that gadusol, a transparent compound discovered over 40 years ago in fish eggs, is a maternally provided sunscreen required for survival of embryonic and larval zebrafish exposed to UVR. Mutating an enzyme involved in gadusol biosynthesis increases the formation of cyclobutane pyrimidine dimers, a hallmark of UVB-induced DNA damage. Compared to the contributions of melanin and the chorion, gadusol is the primary sunscreening mechanism in embryonic and larval fish. The gadusol biosynthetic pathway is retained in the vast majority of teleost genomes but is repeatedly lost in species whose young are no longer exposed to UVR. Our data demonstrate that gadusol is a maternally provided sunscreen that is critical for early-life survival in the most species-rich branch of the vertebrate phylogeny.

Highly Dynamic Gene Family Evolution Suggests Changing Roles for PON Genes Within Metazoa.

Change in gene family size has been shown to facilitate adaptation to different selective pressures. This includes gene duplication to increase dosage or diversification of enzymatic substrates and gene deletion due to relaxed selection. We recently found that the PON1 gene, an enzyme with arylesterase and lactonase activity, was lost repeatedly in different aquatic mammalian lineages, suggesting that the PON gene family is responsive to environmental change. We further investigated if these fluctuations in gene family size were restricted to mammals and approximately when this gene family was expanded within mammals. Using 112 metazoan protein models, we explored the evolutionary history of the PON family to characterize the dynamic evolution of this gene family. We found that there have been multiple, independent expansion events in tardigrades, cephalochordates, and echinoderms. In addition, there have been partial gene loss events in monotremes and sea cucumbers and what appears to be complete loss in arthropods, urochordates, platyhelminths, ctenophores, and placozoans. In addition, we show the mammalian expansion to three PON paralogs occurred in the ancestor of all mammals after the divergence of sauropsida but before the divergence of monotremes from therians. We also provide evidence of a novel PON expansion within the brushtail possum. In the face of repeated expansions and deletions in the context of changing environments, we suggest a range of selective pressures, including pathogen infection and mitigation of oxidative damage, are likely influencing the diversification of this dynamic gene family across metazoa.

Effectiveness and safety of direct oral anticoagulants in patients with venous thromboembolism and creatinine clearance < 30 mL/min.

The few studies that compared direct oral anticoagulants (DOAC) vs. warfarin in the setting of advanced renal insufficiency have focused on patients with atrial fibrillation. The purpose of this observational, matched, cohort study of patients was to assess the effectiveness and safety of DOAC vs. warfarin for the treatment of venous thromboembolism (VTE) among patients with a creatinine clearance (CrCl) < 30 mL/min. This observational, cohort study included patients with VTE and CrCl < 30 mL/min who were newly initiated on a DOAC or warfarin between January 1, 2016 and December 31, 2020. DOAC patients were matched up to 1:2 to warfarin patients. Primary outcome was a composite of recurrent VTE, clinically-relevant bleeding, ischemic stroke, and all-cause mortality. Adjusted conditional, multivariate Cox proportional hazards modeling was used to assess outcomes. 626 DOAC patients were matched to 1071 warfarin patients. DOAC patients had a higher mean age, higher mean baseline CrCl, and were less likely to have been receiving dialysis. There was no statistically significant difference in the composite outcome between groups (adjusted hazard ratio [aHR] 1.13, 95% confidence interval [CI] 0.87-1.47) or in the individual components of the composite (all HR 95% CI crossed 1.00). Identification of statistically non-significant rates of bleeding and thromboembolic outcomes suggest that the use of DOAC or warfarin is reasonable in patients with VTE and CrCl < 30 mL/min.

Complementary evolution of coding and noncoding sequence underlies mammalian hairlessness.

Body hair is a defining mammalian characteristic, but several mammals, such as whales, naked mole-rats, and humans, have notably less hair. To find the genetic basis of reduced hair quantity, we used our evolutionary-rates-based method, RERconverge, to identify coding and noncoding sequences that evolve at significantly different rates in so-called hairless mammals compared to hairy mammals. Using RERconverge, we performed a genome-wide scan over 62 mammal species using 19,149 genes and 343,598 conserved noncoding regions. In addition to detecting known and potential novel hair-related genes, we also discovered hundreds of putative hair-related regulatory elements. Computational investigation revealed that genes and their associated noncoding regions show different evolutionary patterns and influence different aspects of hair growth and development. Many genes under accelerated evolution are associated with the structure of the hair shaft itself, while evolutionary rate shifts in noncoding regions also included the dermal papilla and matrix regions of the hair follicle that contribute to hair growth and cycling. Genes that were top ranked for coding sequence acceleration included known hair and skin genes KRT2, KRT35, PKP1, and PTPRM that surprisingly showed no signals of evolutionary rate shifts in nearby noncoding regions. Conversely, accelerated noncoding regions are most strongly enriched near regulatory hair-related genes and microRNAs, such as mir205, ELF3, and FOXC1, that themselves do not show rate shifts in their protein-coding sequences. Such dichotomy highlights the interplay between the evolution of protein sequence and regulatory sequence to contribute to the emergence of a convergent phenotype.

Whales, elephants, humans, and naked mole-rats all share a somewhat rare trait for mammals: their bodies are covered with little to no hair. The common ancestors of each of these species are considerably hairier which must mean that hairlessness evolved multiple times independently. When distantly related species evolve similar traits, it can be interpreted as a certain aspect of their evolution repeating itself. This process is called 'convergent evolution' and may provide insights about how different species were able to arrive at the same outcome. One possibility is that they have undergone similar genetic changes such as turning on or off key genes that play a role in the trait's development. Kowalczyk et al. set out to identify what genetic changes may have contributed to the convergent evolution of hairlessness in unrelated species of mammals. By looking at the genomes of 62 mammalian species, they hoped to link specific genomic elements to the origins of the hairless trait. The genetic sequences under investigation included nearly 20,000 genes that encode information about how to make proteins, as well as 350,000 regulatory sequences composed of non-coding DNA, which specify when and how genes are activated. This marks the first time genetic mechanisms behind various hair traits have been studied in such a diverse group of mammals. Using a computational approach, Kowalczyk et al. identified parts of the genome that have evolved similarly in mammalian species that have lost their hair. They found that genes and regulatory sequences, that had been previously associated with hair growth, accumulated mutations at significantly different rates in hairless versus hairy mammals. This indicates that these regions associated hair growth are also related to evolution of hairlessness. This includes several genes that encode keratin proteins, the main material that makes up hair. The team also reported an increased rate of evolution in genes and regulatory sequences that were not previously known to be involved in hair growth or hairlessness in mammals. Together these results suggest that a specific set of genetic changes have occurred several times in different mammalian lineages to drive the evolution of hairlessness in unrelated species. Kowalczyk et al. describe the parts of the genome that may be involved in controlling hair growth. Once their findings are validated, they could be used to develop treatments for hair loss in humans. Additionally, their computational approach could be applied to other examples of convergent evolution where genomic data is available, allowing scientists to better understand how the same traits evolve in different species.

MAIA, Fc receptor-like 3, supersedes JUNO as IZUMO1 receptor during human fertilization.

Gamete fusion is a critical event of mammalian fertilization. A random one-bead one-compound combinatorial peptide library represented synthetic human egg mimics and identified a previously unidentified ligand as Fc receptor-like 3, named MAIA after the mythological goddess intertwined with JUNO. This immunoglobulin super family receptor was expressed on human oolemma and played a major role during sperm-egg adhesion and fusion. MAIA forms a highly stable interaction with the known IZUMO1/JUNO sperm-egg complex, permitting specific gamete fusion. The complexity of the MAIA isotype may offer a cryptic sexual selection mechanism to avoid genetic incompatibility and achieve favorable fitness outcomes.

Thromboembolic prevention and anticoagulant therapy during the COVID-19 pandemic: updated clinical guidance from the anticoagulation forum.

Thromboembolism is a common and deadly consequence of COVID-19 infection for hospitalized patients. Based on clinical evidence pre-dating the COVID-19 pandemic and early observational reports, expert consensus and guidance documents have strongly encouraged the use of prophylactic anticoagulation for patients hospitalized for COVID-19 infection. More recently, multiple clinical trials and larger observational studies have provided evidence for tailoring the approach to thromboprophylaxis for patients with COVID-19. This document provides updated guidance for the use of anticoagulant therapies in patients with COVID-19 from the Anticoagulation Forum, the leading North American organization of anticoagulation providers. We discuss ambulatory, in-hospital, and post-hospital thromboprophylaxis strategies as well as provide guidance for patients with thrombotic conditions who are considering COVID-19 vaccination.

Multiple 9-1-1 complexes promote homolog synapsis, DSB repair, and ATR signaling during mammalian meiosis.

DNA damage response mechanisms have meiotic roles that ensure successful gamete formation. While completion of meiotic double-strand break (DSB) repair requires the canonical RAD9A-RAD1-HUS1 (9A-1-1) complex, mammalian meiocytes also express RAD9A and HUS1 paralogs, RAD9B and HUS1B, predicted to form alternative 9-1-1 complexes. The RAD1 subunit is shared by all predicted 9-1-1 complexes and localizes to meiotic chromosomes even in the absence of HUS1 and RAD9A. Here, we report that testis-specific disruption of RAD1 in mice resulted in impaired DSB repair, germ cell depletion, and infertility. Unlike Hus1 or Rad9a disruption, Rad1 loss in meiocytes also caused severe defects in homolog synapsis, impaired phosphorylation of ATR targets such as H2AX, CHK1, and HORMAD2, and compromised meiotic sex chromosome inactivation. Together, these results establish critical roles for both canonical and alternative 9-1-1 complexes in meiotic ATR activation and successful prophase I completion.