Dysfunction of Drosophila mitochondrial carrier homolog (Mtch) alters apoptosis and disturbs development.

Mitochondrial carrier homologs 1 (MTCH1) and 2 (MTCH2) are orphan members of the mitochondrial transporter family SLC25. Human MTCH1 is also known as presenilin 1-associated protein, PSAP. MTCH2 is a receptor for tBid and is related to lipid metabolism. Both proteins have been recently described as protein insertases of the outer mitochondrial membrane. We have depleted Mtch in Drosophila and show here that mutant flies are unable to complete development, showing an excess of apoptosis during pupation; this observation was confirmed by RNAi in Schneider cells. These findings are contrary to what has been described in humans. We discuss the implications in view of recent reports concerning the function of these proteins.

Genetically engineered pair of cells for serological testing and its application for SARS-CoV-2.

We have developed a serology test platform for identifying individuals with prior exposure to specific viral infections and provide data to help reduce public health risks. The serology test composed of a pair of cell lines engineered to express either a viral envelop protein (Target Cell) or a receptor to recognize the Fc region of an antibody (Reporter Cell), that is, Diagnostic-Cell-Complex (DxCell-Complex). The formation of an immune synapse, facilitated by the analyte antibody, resulted into a dual-reporter protein expression by the Reporter Cell. We validated it with human serum with confirmed history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. No signal amplification steps were necessary. The DxCell-Complex quantitatively detected the target-specific immunoglobulin G (IgG) within 1 h. Validation with clinical human serum containing SARS-CoV-2 IgG antibodies confirmed 97.04% sensitivity and 93.33% specificity. The platform can be redirected against other antibodies. Self-replication and activation-induced cell signaling, two attributes of the cell, will enable rapid and cost-effective manufacturing and its operation in healthcare facilities without requiring time-consuming signal amplification steps.

Cell-Based Platform for Antigen Testing and Its Application for SARS-CoV-2 Infection.

We have engineered a cell that can be used for diagnosing active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Isolation of individuals with active infections offers an effective solution for mitigating pandemics. However, the implementation of this practice requires robust infrastructure for rapid and intuitive testing, which is currently missing in our communities. To address this need, we engineered a fast-growing cell line into a cell-based antigen test platform for emerging viruses, i.e., DxCell, that can be rapidly deployed in decentralized health care facilities for continuous testing. The technology was characterized using cells engineered to present spike glycoprotein of SARS-CoV-2 (SARS-CoV-2-Sgp-cells) and Calu-3 host cells infected with competent SARS-CoV-2. Preclinical validation was conducted by directly incubating the DxCell with oropharyngeal swabs from mice infected with SARS-CoV-2. No sample preparation steps are necessary. The DxCell quantitatively detected the SARS-CoV-2-Sgp-cells within 1 h (P < 0.02). Reporter signal was proportional to the number of SARS-CoV-2-Sgp-cells, which represents the infection burden. The SARS-CoV-2 DxCell antigen test was benchmarked against quantitative PCR (qPCR) test and accurately differentiated between infected (n = 8) and control samples (n = 3) (P < 0.05). To demonstrate the broad applicability of the platform, we successfully redirected its specificity and tested its sensing function with cells engineered to present antigens from other viruses. In conclusion, we have developed an antigen test platform that capitalizes on the two innate functions of the cell, self-replication and activation-induced cell signaling. These provide the DxCell key advantages over existing technologies, e.g., label-free testing without sample processing, and will facilitate its implementation in decentralized health care facilities. IMPORTANCE Pandemic mitigation requires continuous testing of symptomatic or asymptomatic individuals with rapid turnaround time, and lack of this capability in our community has prolonged pandemic duration leading to obliteration of world economies. The DxCell platform is a cell-based self-replicative antigen test that detects molecular signatures of the target pathogen and can be distributed in small quantities to testing facilities for expansion on site to the desired volume. In this work, we directed this platform to target SARS-CoV-2. Unlike the PCR detection of viral mRNA that requires trained personnel, the DxCell does not require any sample preparation or signal amplification step and introduces an opportunity for a decentralized testing network.

Altered Expression of ACE2 and Co-receptors of SARS-CoV-2 in the Gut Mucosa of the SIV Model of HIV/AIDS.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of the COVID-19 pandemic, is initiated by its binding to the ACE2 receptor and other co-receptors on mucosal epithelial cells. Variable outcomes of the infection and disease severity can be influenced by pre-existing risk factors. Human immunodeficiency virus (HIV), the cause of AIDS, targets the gut mucosal immune system and impairs epithelial barriers and mucosal immunity. We sought to determine the impact and mechanisms of pre-existing HIV infection increasing mucosal vulnerability to SARS-CoV-2 infection and disease. We investigated changes in the expression of ACE2 and other SARS-CoV-2 receptors and related pathways in virally inflamed gut by using the SIV infected rhesus macaque model of HIV/AIDS. Immunohistochemical analysis showed sustained/enhanced ACE2 expression in the gut epithelium of SIV infected animals compared to uninfected controls. Gut mucosal transcriptomic analysis demonstrated enhanced expression of host factors that support SARS-CoV-2 entry, replication, and infection. Metabolomic analysis of gut luminal contents revealed the impact of SIV infection as demonstrated by impaired mitochondrial function and decreased immune response, which render the host more vulnerable to other pathogens. In summary, SIV infection resulted in sustained or increased ACE2 expression in an inflamed and immune-impaired gut mucosal microenvironment. Collectively, these mucosal changes increase the susceptibility to SARS-CoV-2 infection and disease severity and result in ineffective viral clearance. Our study highlights the use of the SIV model of AIDS to fill the knowledge gap of the enteric mechanisms of co-infections as risk factors for poor disease outcomes, generation of new viral variants and immune escape in COVID-19.

[Inhibitory activity of the ethanolic extract of Cyperus Rotundus from the Cajamarca region (Contumazá province) in a standardize strain of Streptococcus mutans (ATCC ® 25175 TM )]. / Actividad inhibitoria del extracto etanólico del Cyperus Rotundus procedente de la región de Cajamarca (provincia de Contumazá) en una cepa estandarizada de Streptococcus mutans (ATCC ® 25175 TM ).

Objective: The purpose of this study was to determine in vitro the inhibitory activity of the ethanolic extract of Cyperus rotundus (Cajamarca - Contumazá) against a standardize strain of Streptococcus mutans (ATCC®25175™). Materials and methods: This study was an experimental in vitro study, which consisted of determining the inhibitory effect of three concentrations of the ethanolic extract of Cyperus rotundus: 250 mg/ml, 500 mg/ml, and 1000 mg/ml against a strains of Streptococcus mutans (ATCC®25175™). Ten tests were performed for each concentration, having 0.12% chlorhexidine as a positive control for Streptococcus mutans plates and 10% DMSO as a negative control. To evaluate the inhibitory effect, the disk diffusion method or Kirby-Bauer test was used, reading the results at 48 hours after initial sowing. Results: None of the three concentrations of the ethanolic extract of Cyperus rotundus demosntrated inhibitory effects on the Streptococcus mutans strain; however, the positive control, chlorhexidine, clearly showed inhibition halos of 14.43 mm ± 1.23 mm after 48 hours of incubation. Conclusions: The ethanolic extract of Cyperus rotundus did not inhibit the growth of Streptococcus mutans. It is recommended to deepen the chemical analysis of the components of this plant and explore other extraction methods to verify its bacteriostatic action versus other oral and non-oral microorganisms.

Revealing the cryptic diversity of the widespread and poorly known South American blind snake genus Amerotyphlops (Typhlopidae: Scolecophidia) through integrative taxonomy

Morphological stasis is generally associated with relative constancy in ecological pressures throughout time, producing strong stabilizing selection that retains similar shared morphology. Although climate and vegetation are commonly the main key factors driving diversity and phenotypic diversification in terrestrial vertebrates, fossorial organisms have their morphology mostly defined by their fossorial lifestyle. Among these secretive fossorial organisms, blind snakes of the South American genus Amerotyphlops are considered poorly studied when compared to other taxa. Here, we evaluate the cryptic diversity of Amerotyphlops using phylogenetic and multivariate approaches. We based our phylogenetic analysis on a molecular dataset composed of 12 gene fragments (eight nuclear and four mitochondrial) for 109 species of Typhlopidae. The multivariate analysis was implemented using 36 morphological variables for 377 specimens of Amerotyphlops. Additionally, we contrast our phylogenetic result with the morphological variation found in cranial, external and hemipenial traits. Our phylogenetic results recovered with strong support the following monophyletic groups within Amerotyphlops: (1) a clade formed by A. tasymicris and A. minuisquamus; (2) a clade composed of A. reticulatus; (3) a north-eastern Brazilian clade including A. yonenagae, A. arenensis, A. paucisquamus and A. amoipira; and (4) a clade composed of A. brongersmianus and a complex of cryptic species. Based on these results we describe four new species of Amerotyphlops from north-eastern and south-eastern Brazil, which can be distinguished from the morphologically similar species, A. brongersmianus and A. arenensis.

Inactivation of SARS-CoV-2 in clinical exhaled breath condensate samples for metabolomic analysis.

Exhaled breath condensate (EBC) is routinely collected and analyzed in breath research. Because it contains aerosol droplets, EBC samples from SARS-CoV-2 infected individuals harbor the virus and pose the threat of infectious exposure. We report for the first time a safe and consistent method to fully inactivate SARS-CoV-2 in EBC samples and make EBC samples safe for processing and analysis. EBC samples containing infectious SARS-CoV-2 were treated with several concentrations of acetonitrile. The most commonly used 10% acetonitrile treatment for EBC processing failed to completely inactivate the virus in samples and viable virus was detected by the assay of SARS-CoV-2 infection of Vero E6 cells in a biosafety level 3 laboratory. Treatment with either 50% or 90% acetonitrile was effective to completely inactivate the virus, resulting in safe, non-infectious EBC samples that can be used for metabolomic analysis. Our study provides SARS-CoV-2 inactivation protocol for the collection and processing of EBC samples in the clinical setting and for advancing to metabolic assessments in health and disease.

Plasma colloid osmotic pressure in preeclampsia. Review of the Mexican literature 1997-2018.

En México, la presión coloidosmótica del plasma ha sido un tema clave del estudio de la mujer embarazada por más de dos décadas. Las investigaciones clínicas han permitido conocer sus valores en población abierta, mujeres con embarazo normal, puerperio fisiológico, preeclampsia severa, síndrome HELLP y eclampsia. También se ha reportado la relación de la presión coloidosmótica del plasma con la presión sanguínea (índice de Briones), síndrome de fuga capilar y la acumulación de líquido en cavidades serosas (derrame pleural, ascitis). Revisamos la base de datos PubMed, The Cochrane Library, OVID, Science Direct, Google Scholar, Artemisa, LILACS e IMBIOMED de 1997 a 2018 con las siguientes palabras clave: albúmina sérica, presión coloidosmótica del plasma, síndrome de fuga capilar, índice de Briones, derrame pleural, ascitis, preeclampsia severa, síndrome HELLP, eclampsia y cuidados críticos en obstetricia. Los criterios de inclusión fueron revisiones sistemáticas, meta-análisis, ensayos clínicos controlados y artículos con metodología de medicina basada en evidencia con recomendaciones sólidas. Incluimos 12 artículos mexicanos. Los objetivos de la presente investigación fueron: revisar la literatura médica de la presión coloidosmótica del plasma en preeclampsia reportada de 1997 a 2018, describir el tratamiento con albúmina humana y las perspectivas de la investigación en los siguientes años.In Mexico, plasma colloid osmotic pressure has been a key issue in the study of pregnant women for more than two decades. Clinical investigations have allowed to know their values in the open population, as well as in women with normal pregnancy, physiological puerperium, severe preeclampsia, HELLP syndrome, and eclampsia. The relationship of plasma colloid osmotic pressure with mean arterial pressure (Briones index), capillary leak syndrome and the accumulation of fluid in serous cavities (pleural effusion, and ascites) have also been reported. We reviewed the database of PubMed, The Cochrane Library, OVID, Science Direct, Google Scholar, Artemisa, LILACS, and IMBIOMED from 1997 to 2018 with the following keywords: serum albumin, plasma colloid osmotic pressure, capillary leak syndrome, Briones index, pleural effusion, ascites, severe preeclampsia, HELLP syndrome, eclampsia, and obstetrics critical care. Inclusion criteria were systematic reviews, meta-analysis, clinical controlled trials, and articles with evidence-based medicine methodology with strong recommendations. We included 12 Mexican articles. The objectives of the present investigation were to review the medical literature on plasma colloid osmotic pressure in preeclampsia reported from 1997 to 2018, describe the treatment with human albumin and the perspectives of the research in the following years.

Gut germinal center regeneration and enhanced antiviral immunity by mesenchymal stem/stromal cells in SIV infection.

Although antiretroviral therapy suppresses HIV replication, it does not eliminate viral reservoirs or restore damaged lymphoid tissue, posing obstacles to HIV eradication. Using the SIV model of AIDS, we investigated the effect of mesenchymal stem/stromal cell (MSC) infusions on gut mucosal recovery, antiviral immunity, and viral suppression and determined associated molecular/metabolic signatures. MSC administration to SIV-infected macaques resulted in viral reduction and heightened virus-specific responses. Marked clearance of SIV-positive cells from gut mucosal effector sites was correlated with robust regeneration of germinal centers, restoration of follicular B cells and T follicular helper (Tfh) cells, and enhanced antigen presentation by viral trapping within the follicular DC network. Gut transcriptomic analyses showed increased antiviral response mediated by pathways of type I/II IFN signaling, viral restriction factors, innate immunity, and B cell proliferation and provided the molecular signature underlying enhanced host immunity. Metabolic analysis revealed strong correlations between B and Tfh cell activation, anti-SIV antibodies, and IL-7 expression with enriched retinol metabolism, which facilitates gut homing of antigen-activated lymphocytes. We identified potentially new MSC functions in modulating antiviral immunity for enhanced viral clearance predominantly through type I/II IFN signaling and B cell signature, providing a road map for multipronged HIV eradication strategies.

Clinical and anatomopathological aspects of Stryphnodendron fissuratum poisoning in cattle and sheep.

Spontaneous and experimental Stryphnodendron fissuratum poisoning in cattle have been documented in the scientific literature. However, clinical and anatomopathological aspects of such poisoning are not fully understood. Thus, the objective of this study was to describe the clinical, biochemical, gross and microscopic findings of spontaneous Stryphnodendron fissuratum poisoning in cattle as well the experimental poisoning by this plant in sheep. Three outbreaks in cattle from different farms were analyzed. From these farms, S. fissuratum fruit specimens were collected and subsequently administered to six sheep. Some cattle showed clinical signs of poisoning such as blindness, apathy, dysphagia, excessive drooling, weight loss and photodermatitis. In the experimental poisoning condition, one sheep received only the peel of the fruit, one received the seed, and the others received the whole fruit. The whole fruit caused fatal poisoning in one sheep, which showed anorexia, excessive drooling, nystagmus, and paddling. Necropsies and clinical, histopathological, and pathological examination of poisoned cattle and sheep showed that the plant may cause acute renal failure along with extrarenal uremic lesions.

Complicaciones maternas durante la cesárea en pacientes con preeclampsia severa / Maternal complications during cesarean section in patients with severe preeclampsia

Resumen OBJETIVO: Identificar las complicaciones maternas durante la cesárea en pacientes con preeclampsia severa. MATERIALES Y MÉTODOS: Estudio retrospectivo, transversal y descriptivo efectuado en pacientes embarazadas con preeclampsia severa atendidas en la Unidad Médica de Alta Especialidad del Hospital de Gineco-Obstetricia 3 del Centro Médico Nacional La Raza entre el 1 de septiembre de 2020 y el 31 de mayo del año 2021. Se registraron: la indicación de la cirugía (materna o feto-placentaria), las complicaciones y su desenlace, el tiempo de estancia en la unidad de cuidados intensivos y en hospitalización y la muerte materna. Se utilizó estadística descriptiva con el programa estadístico SPSS v 20. RESULTADOS: Se estudiaron 100 pacientes con media de edad de 30.5 ± 5.85 años (límites 17 y 43), mediana de la paridad 2 (límites 1 y 6), semanas de embarazo 33.08 ± 3.9 (límites 26 y 39.4), peso 77.98 ± 15.87 kg (límites 42 y 120), talla 1.57 ± 0.07 m (límites 1.36 y 1.73) e IMC 31.46 ± 5.54 (límites 22.15 y 48.44). 90 de ellas finalizaron el embarazo por cesárea indicada por: crisis hipertensiva (81%), síndrome HELLP (17%), eclampsia (2%) y feto-placentaria en 10% (estado fetal no confiable 5%, ruptura prematura de las membranas 2%, anhidramnios 2%, restricción del crecimiento 1%). Se registraron 12% de complicaciones (atonía uterina (6%), lesión de una arteria uterina (2%), desgarro de la comisura de la histerorrafia (1%), hematoma de la histerorrafia (1%), hematoma del ligamento ancho (1%) y sangrado en capa (1%). Todas las complicaciones se corrigieron en el mismo tiempo quirúrgico. La media del tiempo entre el ingreso a hospitalización hasta la finalización del embarazo fue de 6.26 ± 2.26 horas, estancia en cuidados intensivos 1.36 ± 0.69 días y muerte materna 0%. CONCLUSIÓN: La frecuencia de complicaciones fue baja, quizá por tratarse de pacientes intervenidas en un hospital de alta especialidad.

Abstract OBJECTIVE: To identify maternal complications during cesarean section in patients with severe preeclampsia. MATERIALS AND METHODS: Retrospective, cross-sectional, descriptive study carried out in pregnant patients with severe preeclampsia attended at the High Specialty Medical Unit of the Obstetrics and Gynecology Hospital 3 of the National Medical Center La Raza between September 1, 2020 and May 31, 2021. The following were recorded: indication for surgery (maternal or feto-placental), complications and their outcome, length of stay in the intensive care unit and hospitalization, and maternal death. Descriptive statistics were used with the statistical program SPSS v 20. RESULTS: 100 patients were studied with mean age 30.5 ± 5.85 years (limits 17 and 43), median parity 2 (limits 1 and 6), weeks of pregnancy 33.08 ± 3.9 (limits 26 and 39.4), weight 77.98 ± 15.87 kg (limits 42 and 120), height 1.57 ± 0.07 m (limits 1.36 and 1.73) and BMI 31.46 ± 5.54 (limits 22.15 and 48.44). Ninety of them terminated the pregnancy by cesarean section indicated by: hypertensive crisis (81%), HELLP syndrome (17%), eclampsia (2%) and feto-placental in 10% (unreliable fetal status 5%, premature rupture of membranes 2%, anhydramnios 2%, growth restriction 1%). There were 12% complications (uterine atony (6%), uterine artery injury (2%), hysterorrhaphy commissure tear (1%), hysterorrhaphy hematoma (1%), broad ligament hematoma (1%) and layer bleeding (1%). All complications were corrected within the same surgical time. The mean time from hospitalization to termination of pregnancy was 6.26 ± 2.26 hours, intensive care stay 1.36 ± 0.69 days and maternal death 0%. CONCLUSION: The frequency of complications was low, perhaps because these patients underwent surgery in a high specialty hospital.

Ruptured hepatic hematoma managed with a Sengstaken-Blakemore probe in severe preeclampsia with hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome.

We report the case of a 34-year-old woman with a 32-week pregnancy complicated by recurrent severe preeclampsia, HELLP Class I syndrome, and an intact hepatic hematoma of the right lobe detected by ultrasound. During the cesarean section, the rupture of the hematoma occurred and a gastroesophageal probe of the Sengstaken-Blakemore type was placed to occlude the bleeding cavity and the exit tunnel. The balloons were deflated gradually and the probe was removed on the 10th day without complications. The Sengstaken-Blakemore probe can be an effective remedy to control liver bleeding in selected cases.

Reportamos el caso de una mujer de 34 años con embarazo de 32 semanas complicado con preeclampsia grave recurrente, síndrome HELLP de clase I y hematoma hepático intacto del lóbulo derecho detectado por ultrasonido. Durante la operación cesárea se rompió el hematoma, por lo que se colocó una sonda gastroesofágica de tipo Sengstaken­Blakemore para ocluir la cavidad sangrante y el túnel de salida. Los balones fueron desinflados paulatinamente y la sonda se retiró el décimo día sin complicaciones. La sonda de Sengstaken­Blakemore puede ser un recurso efectivo para controlar el sangrado hepático en casos seleccionados.

Approaches for a field diagnosis of abamectin poisoning in calves / Abordagem para um diagnóstico a campo da intoxicação por abamectina em bezerros

An approach for the diagnosis of an abamectin outbreak in calves in the field is described and discussed. In a Midwestern Brazilian property, nine out of a 52 newborn calves were affected and died, making up for morbidity, mortality, and lethality ratios of 17.3%, 17.3%, and 100%, respectively. Major clinical signs included tremors in various muscle groups, inability to stand, and difficult, wheezing breathing. Each affected calf had been treated subcutaneously with abamectin (0.4mg/kg/body weight). No lesions were found at necropsy or at histological examination. Major diseases of newborn calves were included in the differential diagnosis.(AU)

Uma abordagem para o diagnóstico de um surto de abamectina em bezerros a campo é descrita e discutida. Numa propriedade do Centro-Oeste brasileiro, nove de um lote de 52 bezerros de 3 dias de idade foram afetados e morreram, perfazendo quocientes de morbidade, mortalidade e letalidade, respectivamente, de 17,3%, 17,3% e 100%. Os principais sinais clínicos incluíam tremores em vários grupos musculares, incapacidade em se manter em pé, e respiração difícil e estertorosa. Cada bezerro afetado havia sido tratado por via subcutânea com abamectina, na dose de 0,4mg/kg/peso corporal. Não foram encontradas lesões na necropsia, nem no exame histológico. As principais doenças de bezerros recém-nascidos foram incluídas no diagnóstico diferencial.(AU)

PPARα-targeted mitochondrial bioenergetics mediate repair of intestinal barriers at the host-microbe intersection during SIV infection.

Chronic gut inflammatory diseases are associated with disruption of intestinal epithelial barriers and impaired mucosal immunity. HIV-1 (HIV) causes depletion of mucosal CD4+ T cells early in infection and disruption of gut epithelium, resulting in chronic inflammation and immunodeficiency. Although antiretroviral therapy (ART) is effective in suppressing viral replication, it is incapable of restoring the "leaky gut," which poses an impediment for HIV cure efforts. Strategies are needed for rapid repair of the epithelium to protect intestinal microenvironments and immunity in inflamed gut. Using an in vivo nonhuman primate intestinal loop model of HIV/AIDS, we identified the pathogenic mechanism underlying sustained disruption of gut epithelium and explored rapid repair of gut epithelium at the intersection of microbial metabolism. Molecular, immunological, and metabolomic analyses revealed marked loss of peroxisomal proliferator-activated receptor-α (PPARα) signaling, predominant impairment of mitochondrial function, and epithelial disruption both in vivo and in vitro. To elucidate pathways regulating intestinal epithelial integrity, we introduced probiotic Lactobacillus plantarum into Simian immunodeficiency virus (SIV)-inflamed intestinal lumen. Rapid recovery of the epithelium occurred within 5 h of L. plantarum administration, independent of mucosal CD4+ T cell recovery, and in the absence of ART. This intestinal barrier repair was driven by L. plantarum-induced PPARα activation and restoration of mitochondrial structure and fatty acid ß-oxidation. Our data highlight the critical role of PPARα at the intersection between microbial metabolism and epithelial repair in virally inflamed gut and as a potential mitochondrial target for restoring gut barriers in other infectious or gut inflammatory diseases.

Correction: Large-scale molecular phylogeny, morphology, divergence-time estimation, and the fossil record of advanced caenophidian snakes (Squamata: Serpentes).

[This corrects the article DOI: 10.1371/journal.pone.0216148.].

Large-scale molecular phylogeny, morphology, divergence-time estimation, and the fossil record of advanced caenophidian snakes (Squamata: Serpentes).

Caenophidian snakes include the file snake genus Acrochordus and advanced colubroidean snakes that radiated mainly during the Neogene. Although caenophidian snakes are a well-supported clade, their inferred affinities, based either on molecular or morphological data, remain poorly known or controversial. Here, we provide an expanded molecular phylogenetic analysis of Caenophidia and use three non-parametric measures of support-Shimodaira-Hasegawa-Like test (SHL), Felsentein (FBP) and transfer (TBE) bootstrap measures-to evaluate the robustness of each clade in the molecular tree. That very different alternative support values are common suggests that results based on only one support value should be viewed with caution. Using a scheme to combine support values, we find 20.9% of the 1265 clades comprising the inferred caenophidian tree are unambiguously supported by both SHL and FBP values, while almost 37% are unsupported or ambiguously supported, revealing the substantial extent of phylogenetic problems within Caenophidia. Combined FBP/TBE support values show similar results, while SHL/TBE result in slightly higher combined values. We consider key morphological attributes of colubroidean cranial, vertebral and hemipenial anatomy and provide additional morphological evidence supporting the clades Colubroides, Colubriformes, and Endoglyptodonta. We review and revise the relevant caenophidian fossil record and provide a time-calibrated tree derived from our molecular data to discuss the main cladogenetic events that resulted in present-day patterns of caenophidian diversification. Our results suggest that all extant families of Colubroidea and Elapoidea composing the present-day endoglyptodont fauna originated rapidly within the early Oligocene-between approximately 33 and 28 Mya-following the major terrestrial faunal turnover known as the "Grande Coupure" and associated with the overall climate shift at the Eocene-Oligocene boundary. Our results further suggest that the caenophidian radiation originated within the Caenozoic, with the divergence between Colubroides and Acrochordidae occurring in the early Eocene, at ~ 56 Mya.

Large-scale molecular phylogeny, morphology, divergence-time estimation, and the fossil record of advanced caenophidian snakes (Squamata: Serpentes)

Caenophidian snakes include the file snake genus Acrochordus and advanced colubroidean snakes that radiated mainly during the Neogene. Although caenophidian snakes are a well-supported clade, their inferred affinities, based either on molecular or morphological data, remain poorly known or controversial. Here, we provide an expanded molecular phylogenetic analysis of Caenophidia and use three non-parametric measures of support–Shimodaira-Hasegawa-Like test (SHL), Felsentein (FBP) and transfer (TBE) bootstrap measures–to evaluate the robustness of each clade in the molecular tree. That very different alternative support values are common suggests that results based on only one support value should be viewed with caution. Using a scheme to combine support values, we find 20.9% of the 1265 clades comprising the inferred caenophidian tree are unambiguously supported by both SHL and FBP values, while almost 37% are unsupported or ambiguously supported, revealing the substantial extent of phylogenetic problems within Caenophidia. Combined FBP/TBE support values show similar results, while SHL/TBE result in slightly higher combined values. We consider key morphological attributes of colubroidean cranial, vertebral and hemipenial anatomy and provide additional morphological evidence supporting the clades Colubroides, Colubriformes, and Endoglyptodonta. We review and revise the relevant caenophidian fossil record and provide a time-calibrated tree derived from our molecular data to discuss the main cladogenetic events that resulted in present-day patterns of caenophidian diversification. Our results suggest that all extant families of Colubroidea and Elapoidea composing the present-day endoglyptodont fauna originated rapidly within the early Oligocene–between approximately 33 and 28 Mya–following the major terrestrial faunal turnover known as the "Grande Coupure" and associated with the overall climate shift at the Eocene-Oligocene boundary. Our results further suggest that the caenophidian radiation originated within the Caenozoic, with the divergence between Colubroides and Acrochordidae occurring in the early Eocene, at ~ 56 Mya.

Molecular phylogeny and hemipenial diversity of South American species of Amerotyphlops (Typhlopidae, Scolecophidia)

Typhlopidae is the most diverse family of Scolecophidia, with 269 species. Amerotyphlops was recently erected within subfamily Typhlopinae and comprises fifteen species distributed from Mexico to Argentina and the southern Lesser Antilles. Despite recent advances, affinities among typhlopines remain poorly explored, and the phylogenetic relationships and morphology of the South American (SA) species were never accessed before. Here, we performed a phylogenetic analysis including 106 species of Typhlopidae and ten genes. Our dataset represents the most comprehensive for SA species, containing seven of eight recognized species. Corroborating previous studies, we recovered the main groups of Typhlopoidea, and for typhlopines, we recovered with strong support two clades: (a) the Greater Antilles radiation, and the (b) Lesser Antilles and SA radiation. Within the SA radiation, we recovered four main lineages: (a) a clade formed by A. tasymicris and A. minuisquamus; (b) a clade composed by A. reticulatus as the sister group of all other SA species; (c) a clade composed by A. brongersmianus as the sister group of a clade comprising all Northeast Brazilian Species (NBS); and (d) a clade of the NBS, including A. yonenagae, A. arenensis, A. paucisquamus, and A. amoipira. We supplemented our phylogenetic result with the description of hemipenial morphology for seven SA species and comment their relevance to the systematics of Typhlopinae. Hemipenes of SA Amerotyphlops follow the general pattern in scolecophidians (single organ with undivided sulcus). Only A. reticulatus and A. minuisquamus have organs with calcified spines. According to our results, hemipenial ornamentation have shown highly informative and could represent a potential source of systematic and taxonomic characters in that group. We also present an extensive review of the geographical distribution for all SA species. Our study represents the first integrative analysis of a poorly known evolutionary radiation of one of the most widespread SA fossorial snakes.

Large-scale molecular phylogeny, morphology, divergence-time estimation, and the fossil record of advanced caenophidian snakes (Squamata: Serpentes)

Caenophidian snakes include the file snake genus Acrochordus and advanced colubroidean snakes that radiated mainly during the Neogene. Although caenophidian snakes are a well-supported clade, their inferred affinities, based either on molecular or morphological data, remain poorly known or controversial. Here, we provide an expanded molecular phylogenetic analysis of Caenophidia and use three non-parametric measures of support–Shimodaira-Hasegawa-Like test (SHL), Felsentein (FBP) and transfer (TBE) bootstrap measures–to evaluate the robustness of each clade in the molecular tree. That very different alternative support values are common suggests that results based on only one support value should be viewed with caution. Using a scheme to combine support values, we find 20.9% of the 1265 clades comprising the inferred caenophidian tree are unambiguously supported by both SHL and FBP values, while almost 37% are unsupported or ambiguously supported, revealing the substantial extent of phylogenetic problems within Caenophidia. Combined FBP/TBE support values show similar results, while SHL/TBE result in slightly higher combined values. We consider key morphological attributes of colubroidean cranial, vertebral and hemipenial anatomy and provide additional morphological evidence supporting the clades Colubroides, Colubriformes, and Endoglyptodonta. We review and revise the relevant caenophidian fossil record and provide a time-calibrated tree derived from our molecular data to discuss the main cladogenetic events that resulted in present-day patterns of caenophidian diversification. Our results suggest that all extant families of Colubroidea and Elapoidea composing the present-day endoglyptodont fauna originated rapidly within the early Oligocene–between approximately 33 and 28 Mya–following the major terrestrial faunal turnover known as the "Grande Coupure" and associated with the overall climate shift at the Eocene-Oligocene boundary. Our results further suggest that the caenophidian radiation originated within the Caenozoic, with the divergence between Colubroides and Acrochordidae occurring in the early Eocene, at ~ 56 Mya.

Molecular phylogeny and hemipenial diversity of South American species of Amerotyphlops (Typhlopidae, Scolecophidia)

Typhlopidae is the most diverse family of Scolecophidia, with 269 species. Amerotyphlops was recently erected within subfamily Typhlopinae and comprises fifteen species distributed from Mexico to Argentina and the southern Lesser Antilles. Despite recent advances, affinities among typhlopines remain poorly explored, and the phylogenetic relationships and morphology of the South American (SA) species were never accessed before. Here, we performed a phylogenetic analysis including 106 species of Typhlopidae and ten genes. Our dataset represents the most comprehensive for SA species, containing seven of eight recognized species. Corroborating previous studies, we recovered the main groups of Typhlopoidea, and for typhlopines, we recovered with strong support two clades: (a) the Greater Antilles radiation, and the (b) Lesser Antilles and SA radiation. Within the SA radiation, we recovered four main lineages: (a) a clade formed by A. tasymicris and A. minuisquamus; (b) a clade composed by A. reticulatus as the sister group of all other SA species; (c) a clade composed by A. brongersmianus as the sister group of a clade comprising all Northeast Brazilian Species (NBS); and (d) a clade of the NBS, including A. yonenagae, A. arenensis, A. paucisquamus, and A. amoipira. We supplemented our phylogenetic result with the description of hemipenial morphology for seven SA species and comment their relevance to the systematics of Typhlopinae. Hemipenes of SA Amerotyphlops follow the general pattern in scolecophidians (single organ with undivided sulcus). Only A. reticulatus and A. minuisquamus have organs with calcified spines. According to our results, hemipenial ornamentation have shown highly informative and could represent a potential source of systematic and taxonomic characters in that group. We also present an extensive review of the geographical distribution for all SA species. Our study represents the first integrative analysis of a poorly known evolutionary radiation of one of the most widespread SA fossorial snakes.