Amazonian White-Sand Forests Show Strong Floristic Links with Surrounding Oligotrophic Habitats and the Guiana Shield

Recognizing and understanding historical patterns and processes that have influenced the diversification of organisms on earth is one of the central goals of evolutionary biology. Within this broad area, studies within the disciplines of molecular systematics (i.e. phylogeography, phylogenetics and population genetics), allow us to address evolutionary questions from different biological, spatial and temporal scales. Phylogeography and molecular phylogenetics help us to understand aspects related to events that have given rise to patterns of genetic variation in organisms, as well as to understand the assembly of biological communities in a given area. These types of studies provide crucial information to increase knowledge about the biodiversity of little-studied ecoregions. One such ecoregion is Colombian Guyana. This ecoregion, which is located between three putative centers of speciation; Amazonia, the Andes and Guyana, is one of the least explored areas of the country. As a result of their geological composition, the western enclaves of the Guiana Shield have been described as a "heterogeneous entity", composed of savannas, catingas, lowland forests, and even white sand forests. Using bats as a biological study group, this paper presents two approaches focused on understanding how biogeographic events that have shaped the diversity of the continent have affected different lineages that inhabit Colombian Guiana. Bats are a group of vertebrates sensitive to biogeographic events that have shaped the diversity of the continent, which play different functional roles in the ecosystems they inhabit. High degrees of association with habitat have been described for numerous bat species, mainly in terms of foraging characteristics and diet types. In a first project, we comparatively analyzed the phylogeographic patterns of three widely distributed bat species, with the aim of identifying the patterns of genetic divergence of the bats that inhabit the area today. Using mitochondrial DNA sequences, we revealed the existence of bat populations established in the area, which showed different degrees of gene flow with surrounding biogeographic areas, especially with the Guiana provinces of Oriente and Pantepui and the Amazon. Additionally, we identified different demographic histories for each species, which were probably influenced to different extents by climatic changes during the Pleistocene and differential ecological characteristics. Our results highlight the influence of Colombian Guiana ecosystems on the formation and spatial configuration of bat diversity and genetic structure, and the importance of these ecosystems for bat conservation. In a second project, from a phylogenetic perspective, we evaluated the phylogenetic structure of bat communities inhabiting different eco-regions of northern South America, using mitochondrial and nuclear DNA sequences. The results of the analysis allowed us to demonstrate that the bat populations of the Western Guayana Province (which includes the Colombian portion of the Guiana Shield), are phylogenetically clustered, that is, the species that compose the communities are evolutionarily closer than expected by chance. We conclude that factors such as the high heterogeneity of habitats in the region, the high diversity of fruit bats in the sampled communities, and interspecific competition have shaped the species composition of the communities in this area. In a final chapter, a general discussion of the results obtained from the two research projects carried out is developed. Chapters one and two of this thesis will be submitted to international indexed journals, which is why they are written in English and in scientific article format.Reconocer y entender patrones y procesos históricos que han influenciado la diversificación de los organismos sobre la tierra, es uno de los objetivos centrales de la biología evolutiva. Dentro de esta gran área, estudios enmarcados en las disciplinas de la sistemática molecular (i.e. filogeografía, filogenética y genética de poblaciones), nos permiten abordar preguntas evolutivas desde diferentes escalas biológicas, espaciales y temporales. La filogeografía y la filogenética molecular nos ayudan a entender aspectos relacionados con eventos que han dado lugar a patrones de variación genética de los organismos, así como entender el ensamblaje de comunidades biológicas en un área determinada. Este tipo de estudios aportan información crucial para aumentar el conocimiento acerca de biodiversidad de eco regiones poco estudiadas. Una de estas eco regiones es la Guyana colombiana. Esta eco región, la cual se encuentra ubicada entre tres centros putativos de especiación; Amazonía, Andes y Guayana, es una de las zonas menos exploradas del país. Como resultado de su composición geológica, los enclaves occidentales del escudo Guayanés han sido descritos como una "entidad heterogénea", compuesta de sabanas, catingas, bosques bajos, e inclusive bosques de arena blanca. Usando como grupo biológico de estudio los murciélagos, este trabajo de grado presentan dos aproximaciones enfocadas a entender como eventos biogeográficos que han moldeado la diversidad del continente, han afectado diferentes linajes que habitan la Guayana colombiana. Los murciélagos son un grupo de vertebrados sensibles a los eventos biogeográficos que han moldeado la diversidad del continente, el cuál cumple diferentes roles funcionales en los ecosistemas que habitan. Altos grados de asociación con el hábitat han sido descritos para numerosas especies de murciélagos, principalmente en cuanto a características de forrajeo y tipos de dieta. En un primer proyecto, analizamos comparativamente los patrones filogeográficos de tres especies de murciélagos de amplia distribución, con el objetivo de identificar los patrones de divergencia genética de los murciélagos que habitan el área en la actualidad. Utilizando secuencias de ADN mitocondrial, revelamos la existencia de poblaciones de murciélagos establecidas en el área, las cuales mostraron diferentes grados de flujo genético con áreas biogeográficas circundantes, en especial con las provincias guayanesas del Oriente y Pantepui y el Amazonas. Adicionalmente identificamos diferentes historias demográficas para cada especie, las cuales probablemente fueron influenciadas en diferente medida por cambios climáticos durante el pleistoceno y características ecológicas diferenciales. Nuestros resultados destacan la influencia de los ecosistemas guayaneses colombianos en la formación y configuración espacial de la diversidad y estructura genética en murciélagos, y la importancia de estos ecosistemas para la conservación dicha diversidad. En un segundo proyecto, desde una perspectiva filogenética, evaluamos la estructura filogenética de la comunidad de murciélagos de diferentes eco-regiones del norte de sur américa, usando secuencia de ADN mitocondrial. Los resultados de los análisis nos permitieron demostrar que las poblaciones de murciélagos de la Provincia Guayanesa del Occidente (la cual incluye la porción colombiana del escudo guayanés), se encuentran filogenéticamente agregadas, es decir, las especies que componen las comunidades son más cercanas evolutivamente de lo esperado por el azar. Concluimos que factores como la alta heterogeneidad de hábitats en la región, la alta diversidad de murciélagos frugívoros en las comunidades muestreadas, y la competencia interespecífica han moldeado la composición de especies de las comunidades en esta zona. En un capítulo final, se desarrolla una discusión general de los resultados obtenidos de los dos proyectos de investigación realizados. Los capítulos uno y dos de esta tesis serán sometidos a revistas indexadas internacionales, razón por la cual están escritos en idioma inglés y en formato de artículo científico.Línea de Investigación: Biología EvolutivaMaestrí

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Aims: The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry. Methods and results: 1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI) and clinical traits was analyzed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene.The prevalence of HT, DM and obesity (Ob) was 37%, 10%, and 21%, respectively. HT, DM and Ob were associated with older age (p<0.001), less family history of HCM (HT and DM p<0.001), higher New York Heart Association (NYHA) class (p<0.001), atrial fibrillation (HT and DM p<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob p<0.001; DM p = 0.003). Stroke was more frequent in HT (p<0.001) and mutation-positive patients with DM (p = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT p<0.001, Ob p = 0.036). LV hypertrophy was more severe in Ob (p = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, p = 0.017 and OR 1.584, p = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients. Conclusion: Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.info:eu-repo/semantics/publishedVersio

Clinical Phenotypes and Prognosis of Dilated Cardiomyopathy Caused by Truncating Variants in the TTN Gene

BACKGROUND: Truncating variants in the TTN gene (TTNtv) are the commonest cause of heritable dilated cardiomyopathy. This study aimed to study the phenotypes and outcomes of TTNtv carriers. METHODS: Five hundred thirty-seven individuals (61% men; 317 probands) with TTNtv were recruited in 14 centers (372 [69%] with baseline left ventricular systolic dysfunction [LVSD]). Baseline and longitudinal clinical data were obtained. The primary end point was a composite of malignant ventricular arrhythmia and end-stage heart failure. The secondary end point was left ventricular reverse remodeling (left ventricular ejection fraction increase by ≥10% or normalization to ≥50%). RESULTS: Median follow-up was 49 (18-105) months. Men developed LVSD more frequently and earlier than women (45±14 versus 49±16 years, respectively; P=0.04). By final evaluation, 31%, 45%, and 56% had atrial fibrillation, frequent ventricular ectopy, and nonsustained ventricular tachycardia, respectively. Seventy-six (14.2%) individuals reached the primary end point (52 [68%] end-stage heart failure events, 24 [32%] malignant ventricular arrhythmia events). Malignant ventricular arrhythmia end points most commonly occurred in patients with severe LVSD. Male sex (hazard ratio, 1.89 [95% CI, 1.04-3.44]; P=0.04) and left ventricular ejection fraction (per 10% decrement from left ventricular ejection fraction, 50%; hazard ratio, 1.63 [95% CI, 1.30-2.04]; P<0.001) were independent predictors of the primary end point. Two hundred seven of 300 (69%) patients with LVSD had evidence of left ventricular reverse remodeling. In a subgroup of 29 of 74 (39%) patients with initial left ventricular reverse remodeling, there was a subsequent left ventricular ejection fraction decrement. TTNtv location was not associated with statistically significant differences in baseline clinical characteristics, left ventricular reverse remodeling, or outcomes on multivariable analysis (P=0.07). CONCLUSIONS: TTNtv is characterized by frequent arrhythmia, but malignant ventricular arrhythmias are most commonly associated with severe LVSD. Male sex and LVSD are independent predictors of outcomes. Mutation location does not impact clinical phenotype or outcomes

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Clinical phenotypes and prognosis of dilated cardiomyopathy caused by truncating variants in the TTN Gene.

Background: Truncating variants in the TTN gene (TTNtv) are the commonest cause of heritable dilated cardiomyopathy. This study aimed to study the phenotypes and outcomes of TTNtv carriers. Methods: Five hundred thirty-seven individuals (61% men; 317 probands) with TTNtv were recruited in 14 centers (372 [69%] with baseline left ventricular systolic dysfunction [LVSD]). Baseline and longitudinal clinical data were obtained. The primary end point was a composite of malignant ventricular arrhythmia and end-stage heart failure. The secondary end point was left ventricular reverse remodeling (left ventricular ejection fraction increase by ≥10% or normalization to ≥50%). Results: Median follow-up was 49 (18–105) months. Men developed LVSD more frequently and earlier than women (45±14 versus 49±16 years, respectively; P=0.04). By final evaluation, 31%, 45%, and 56% had atrial fibrillation, frequent ventricular ectopy, and nonsustained ventricular tachycardia, respectively. Seventy-six (14.2%) individuals reached the primary end point (52 [68%] end-stage heart failure events, 24 [32%] malignant ventricular arrhythmia events). Malignant ventricular arrhythmia end points most commonly occurred in patients with severe LVSD. Male sex (hazard ratio, 1.89 [95% CI, 1.04–3.44]; P=0.04) and left ventricular ejection fraction (per 10% decrement from left ventricular ejection fraction, 50%; hazard ratio, 1.63 [95% CI, 1.30–2.04]; P<0.001) were independent predictors of the primary end point. Two hundred seven of 300 (69%) patients with LVSD had evidence of left ventricular reverse remodeling. In a subgroup of 29 of 74 (39%) patients with initial left ventricular reverse remodeling, there was a subsequent left ventricular ejection fraction decrement. TTNtv location was not associated with statistically significant differences in baseline clinical characteristics, left ventricular reverse remodeling, or outcomes on multivariable analysis (P=0.07). Conclusions: TTNtv is characterized by frequent arrhythmia, but malignant ventricular arrhythmias are most commonly associated with severe LVSD. Male sex and LVSD are independent predictors of outcomes. Mutation location does not impact clinical phenotype or outcomes.pre-print1,66 M

Alpha-protein kinase 3 (ALPK3)-truncating variants are a cause of autosomal dominant hypertrophic cardiomyopathy.

AIMS: The aim of this study was to determine the frequency of heterozygous truncating ALPK3 variants (ALPK3tv) in patients with hypertrophic cardiomyopathy (HCM) and confirm their pathogenicity using burden testing in independent cohorts and family co-segregation studies. METHODS AND RESULTS : In a discovery cohort of 770 index patients with HCM, 12 (1.56%) were heterozygous for ALPK3tv [odds ratio(OR) 16.01, 95% confidence interval (CI) 7.89-29.74, P < 8.36e-11] compared to the Genome Aggregation Database (gnomAD) population. In a validation cohort of 2047 HCM probands, 32 (1.56%) carried heterozygous ALPK3tv (OR 16.17, 95% CI 10.31-24.87, P < 2.2e-16, compared to gnomAD). Combined logarithm of odds score in seven families with ALPK3tv was 2.99. In comparison with a cohort of genotyped patients with HCM (n = 1679) with and without pathogenic sarcomere gene variants (SP+ and SP-), ALPK3tv carriers had a higher prevalence of apical/concentric patterns of hypertrophy (60%, P < 0.001) and of a short PR interval (10%, P = 0.009). Age at diagnosis and maximum left ventricular wall thickness were similar to SP- and left ventricular systolic impairment (6%) and non-sustained ventricular tachycardia (31%) at baseline similar to SP+. After 5.3 ± 5.7 years, 4 (9%) patients with ALPK3tv died of heart failure or had cardiac transplantation (log-rank P = 0.012 vs. SP- and P = 0.425 vs. SP+). Imaging and histopathology showed extensive myocardial fibrosis and myocyte vacuolation. CONCLUSIONS : Heterozygous ALPK3tv are pathogenic and segregate with a characteristic HCM phenotype

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Unidad de excelencia María de Maeztu CEX2019-000940-MAim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Persistent effects of pre-Columbian plant domestication on Amazonian forest composition

The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times more likely to be hyperdominant than non-domesticated species. Across the basin the relative abundance and richness of domesticated species increases in forests on and around archaeological sites. In southwestern and eastern Amazonia distance to archaeological sites strongly influences the relative abundance and richness of domesticated species. Our analyses indicate that modern tree communities in Amazonia are structured to an important extent by a long history of plant domestication by Amazonian peoples

Natural History of MYH7-Related Dilated Cardiomyopathy

BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVE: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of ≤35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century