Phenotypic characteristics and genetic diversity of new broccoli (Brassica oleracea var. italica Plenck) varieties in China

Due to its high nutritional value, broccoli (Brassica oleracea var. italica Plenck) is one of the most popular vegetables worldwide. This study assessed 36 phenotypic characteristics of 111 broccoli varieties to understand the phenotypic diversity of new broccoli varieties and improve their breeding speed with advantages and characteristics in China, including 108 new varieties and three varieties of common knowledge. The genetic diversity, the principal component, and the cluster of phenotypic characteristics of broccoli varieties were further investigated. The results showed that the coefficients of variation of 36 characteristics ranged between 11.18 % and 94.99 %, with their diversity index between 0.26 and 1.82. The 111 broccoli varieties were further classified into eight groups, primarily attributed to the differences in phenotypic characteristics, including curd weight, main stem thickness, plant development degree, plant height, and anthocyanin coloration. The cumulative contribution rate of the first five principal components reached 81.186 %, corresponding to 12 representative phenotypic traits. The analysis indicated that the phenotypic characteristics of broccoli were rich in diversity, especially for several characteristics appreciated by the market, such as weight, curd firmness, and anthocyanin coloration. This study revealed the basic information on the genetic diversity of new broccoli varieties in China from 2017 to 2019 and provided potential breeding strategies for broccoli to meet diverse market demands.

Early effects of gene duplication on the robustness and phenotypic variability of gene regulatory networks.

BACKGROUND: Research on gene duplication is abundant and comes from a wide range of approaches, from high-throughput analyses and experimental evolution to bioinformatics and theoretical models. Notwithstanding, a consensus is still lacking regarding evolutionary mechanisms involved in evolution through gene duplication as well as the conditions that affect them. We argue that a better understanding of evolution through gene duplication requires considering explicitly that genes do not act in isolation. It demands studying how the perturbation that gene duplication implies percolates through the web of gene interactions. Due to evolution's contingent nature, the paths that lead to the final fate of duplicates must depend strongly on the early stages of gene duplication, before gene copies have accumulated distinctive changes. METHODS: Here we use a widely-known model of gene regulatory networks to study how gene duplication affects network behavior in early stages. Such networks comprise sets of genes that cross-regulate. They organize gene activity creating the gene expression patterns that give cells their phenotypic properties. We focus on how duplication affects two evolutionarily relevant properties of gene regulatory networks: mitigation of the effect of new mutations and access to new phenotypic variants through mutation. RESULTS: Among other observations, we find that those networks that are better at maintaining the original phenotype after duplication are usually also better at buffering the effect of single interaction mutations and that duplication tends to enhance further this ability. Moreover, the effect of mutations after duplication depends on both the kind of mutation and genes involved in it. We also found that those phenotypes that had easier access through mutation before duplication had higher chances of remaining accessible through new mutations after duplication. CONCLUSION: Our results support that gene duplication often mitigates the impact of new mutations and that this effect is not merely due to changes in the number of genes. The work that we put forward helps to identify conditions under which gene duplication may enhance evolvability and robustness to mutations.

Caracterización in situ de poblaciones de Aloysia gratissima var. gratissima recolectadas del noreste de la provincia de San Luis, Argentina / In situ characterization of populations of Aloysia gratissima var. gratissima collected from the northeast of the province of San Luis, Argentina

Abstract: The aerial part of Aloysia gratissima (Gil lies & Hook. ex Hook.) Tronc., "Usillo", is used as aromatic and medicinal. It is a shrub of up to 3 meters, distributed in North America, from the south of the USA to the north of Mexico, and in South America up to the 37th parallel. As in other native sp ecies, the demand is covered by harvesting in wild populations, which brings about the deterioration of the resource and lack of homogeneity of the harvested product. The variability was characterized in nine populations of A. gratissima var. gratissima fr om the northeast of San Luis, Argentina, based on morphological and phytochemical characters. It was found that the species in the region presents considerable heterogeneity. Diversity was detected in the chemical characteristics of the essential oils anal yzed and the prevalence of mono and sesquiterpenes was related to the olfactory identities identified. The main components were the sesquiterpene spatulenol and the monoterpene 1,8 cineole

Resumen: La parte aérea de Aloysia gratissima (Gillies & Hook. ex Hook.) Tronc., "usillo", es utilizada como aromática y medicinal. Es un arbusto de hasta 3 metros, distribuido en Norteamerica, desde e l sur de EEUU hasta el norte de México, y en Sudamerica hasta el paralelo 37°. Al igual que en otras especies nativas, la demanda es cubierta por recolección en poblaciones silvestres, lo cual trae aparejado el deterioro del recurso y falta de homogeneidad del producto cosechado. Se caracterizó la variabilidad en nueve poblaciones de A. gratissima var. gratissima del noreste de San Luis, Argentina, en base a caracteres morfológicos y fitoquímicos. Se encontró que la especie en la región presenta una conside rable heterogeneidad. Se detectó diversidad en las características químicas de los aceites esenciales analizados y se relacionó la prevalencia de mono y sesquiterpenos con las identidades olfativas identificadas. Los componentes mayoritarios fueron el sesq uiterpeno espatulenol y el monoterpeno 1,8 cineol.

On the effects of the modularity of gene regulatory networks on phenotypic variability and its association with robustness.

Biological adaptations depend on natural selection sorting out those individuals that exhibit characters fit to their environment. Selection, in turn, depends on the phenotypic variation present in a population. Thus, evolutionary outcomes depend, to a certain extent, on the kind of variation that organisms can produce through random genetic perturbation, that is, their phenotypic variability. Moreover, the properties of developmental mechanisms that produce the organisms affect their phenotypic variability. Two of these properties are modularity and robustness. Modularity is the degree to which interactions occur mostly within groups of the system's elements and scarcely between elements in different groups. Robustness is the propensity of a system to endure perturbations while preserving its phenotype. In this paper, we used a model of gene regulatory networks (GRNs) to study the relationship between modularity and robustness in developmental processes and how modularity affects the variation that random genetic mutations produce in the expression patterns of GRNs. Our results show that modularity and robustness are correlated in multifunctional GRNs and that selection for one of these properties affects the other as well. We contend that these observations may help to understand why modularity and robustness are widespread in biological systems. Additionally, we found that modular networks tend to produce new expression patterns with subtle changes localized in the expression of a few groups of genes. This effect in the phenotypic variability of modular GRNs may bear important consequences for adaptive evolution: it may help to adjust the expression of one group of genes at a time, with few alterations on other previously evolved expression patterns.

Phenotypic diversity of agromorphological characteristics of quinoa (Chenopodium quinoa Willd. ) germplasm in Colombia

Chenopodium quinoa Willd. is an Andean crop with great nutritional value, economic potential, and a broad genetic and phenotypic diversity with adaptation to different conditions. In Colombia, C. quinoa is cultivated mainly in Cundinamarca, Nariño and Boyacá, where studies have been conducted to characterize the germplasm and lack of seed materials, some challenges for the quinoa crop. This work assessed agromorphological characteristics of 50 quinoa genotypes from the germplasm collection of Boyacá the using a completely randomized design on the farm in Tunja. The multivariate analysis followed by a clustering approach were conducted on agromorphological descriptors, in which 16 were qualitative descriptors (e.g, panicle shape, episperm color, leaf shape) and five quantitative descriptors (e.g, plant height, panicle number). The results showed that higher coefficients of variation were found in characteristics associated to yield. The principal component analysis (PCA) of the quantitative variables showed that the first two components explained 88 % of the total variation with the characteristics of plant height, length, diameter, and panicle number showing the highest variability. The quantitative characteristic clusters comprised length and diameter panicle, weight 1,000 seeds, and plant height, while the qualitative characteristic clusters comprised stem shape, branching habit, panicle shape, and color of the axils. The factorial analysis of mixed data discriminated the materials with outstanding morphoagronomic characteristics. Agromorphological characterization revealed a broad variability, which should be conserved and used in genetic improvement programs of C. quinoa.

Acidogenic and aciduric properties of Streptococcus mutans serotype c according to its genomic variability.

Streptococcus mutans (S. mutans) has a wide genetic diversity that contributes to its phenotypic heterogeneity, and may be related to attributes associated with acidogenicity and aciduricity. The aim of this study was to evaluate the acidogenic and aciduric properties of S. mutans serotype c isolates from saliva of schoolchildren according to the genomic variability. S. mutans isolates were identified by polymerase chain reaction. Fifty S. mutans serotype c isolates were genotyped by pulsed field gel electrophoresis and tested for their ability to produce and resist acid. Three specific genotypes were identified in the caries-active group and only one in the caries-free group. Although isolates were similarly acidogenic, an exclusive caries-active genotype had the greatest glycolytic activity. In contrast, isolates exhibited variable aciduricity, and three caries-active genotypes were the least aciduric. We concluded that there is genetic variability within serotype c. Acid production was similar regardless of the caries status but correlated with the number of genotypes. In addition, resistance to acid could be an important characteristic for the establishment and colonisation of specific genotypes in children with caries. However, it is important to evaluate children's intrinsic characteristics and other phenotypic properties to explain the physiopathological behaviour of the different genotypes.

Clinical Exome Sequencing Enables Congenital Sialidosis Type II Diagnosis in Two Siblings Presenting with Unreported Clinical Features from a Rare Homozygous Sequence Variant p.(Tyr370Cys) in NEU1.

Sialidosis is a rare autosomal recessive disease that presents with progressive lysosomal storage of sialylated glycopeptides and oligosaccharides caused by homozygous or compound heterozygous sequence variants in the neuraminidase 1 (NEU1) gene. These sequence variants can lead to sialidosis type I and II; the latter is the most severe and presents prenatally or at early age. However, sialidosis diagnosis is challenging, especially in those health systems with limited resources of developing countries. Consequently, it is necessary to dip into high-throughput molecular diagnostic tools to allow for an accurate diagnosis with better cost-effectiveness and turnaround time. We report a 4-member pedigree segregating an ultrarare missense variant, c.1109A>G; p.Tyr370Cys, in NEU1 as detected by whole-exome sequencing. Two short-lived siblings, who presented with previously unreported clinical features from such a homozygous sequence variant, were diagnosed with sialidosis type II. Additionally, we present a novel molecular model exhibiting the consequences of the variant in the sialidase-1 tridimensional structure. This study allowed us to provide a definitive diagnosis for our patients, increase our understanding of this pathogenic variant, and improve genetic counseling.

Andersen-Tawil Syndrome with High Risk of Sudden Cardiac Death in Four Mexican Patients. Cardiac and Extra-Cardiac Phenotypes

ABSTRACT Background: Andersen-Tawil syndrome (ATS) is a cardiac channelopathy that is inherited in an autosomal dominant way, and it is characterized by a triad of periodic paralysis, ventricular arrhythmias, and includes some dysmorphic features with incomplete penetrance and variable expression that result in a challenging diagnosis. Objective: The objective of the study was to describe the cardiac and extra-cardiac phenotype in a cohort of patients with ATS at risk of sudden cardiac death (SCD) to improve its early clinical identification. Methods: In an observational, transversal study, with a deviant case sampling, four female patients with ATS at high risk of SCD were included in the study. They carried the heterozygous pathogenic variants c.407C>T [p.Ser136Phe], c.652C>T [p.Arg218Trp] (n=2), and c.431G>C [p.Gly144Ala] in the KCNJ2 gene. Patients were evaluated by a cardiologist, a clinical geneticist, and a physiatrist. Results: One patient had the classical facial phenotype and the other three had subtle manifestations. The group of patients presented a diverse set of clinical data such as: triangular face, broad forehead, broadening of medial eyebrows, auricular pits, low-set ears, eyelid ptosis, thin lips, mandibular hypoplasia, and diverse types of dental alterations, single transverse palmar crease, camptodactyly, and syndactyly. Long-exercise test showed a decrement in the percentage amplitude up to 44%, classifying patients in IV or V types according to Fournier’s scale. Conclusions: Extra-cardiac manifestations were a common finding in this series of ATS type1 at high risk of SCD. Its recognition could help the clinician in the early identification of patients with ATS, especially for the cardiologist since they are commonly referred only for evaluation of ventricular arrhythmias.

De novo transcriptome assembly for two color types of the marine sponge Mycale (Carmia) cecilia.

Despite the ecological importance and the potential pharmacological application of the sponge Mycale (Carmia) cecilia, it is uncertain whether the body-color variation, even in individuals coexisting in the same area, is due to intraspecific phenotypic plasticity or corresponds to taxonomic divergence. This uncertainty is relatively common in several Porifera groups, which lack the resolution of morphological diagnostic characters and slow-evolving mitochondrial genomes as occurs in early splitting lineages. We sequenced the RNA of six individuals with two different body-color (green-morphotype and red-morphotype) collected at the same time side by side. High-throughput sequencing of cDNA libraries produced ~ 129 million reads with a length of 150 bp. Each morphotype was assembled separately owing to the low overlapping in the global assembly. Metatranscriptome de novo assembly of the trimmed and normalized reads produced 461 thousand transcripts for the green-morphotype and 342 thousand for the red-morphotype (respectively). Over 30% of the transcripts contained Open Reading Frames (ORFs) with functional significance. BUSCO analysis of the ORFs of putative poriferan origin (31.3% green or 30.4% red) indicated that our assemblies are 60% complete. This is the first attempt to evaluate the morphological diversity in the species M. (C.) cecilia and the phylum Porifera at the transcriptomic level. Due to the minimum overlap of the assembly and that, the red-morphotype diverged significantly from the green-morphotype (original color of M. (C.) cecilia). Therefore, we suggest that the red-morphotype should undergo a complete taxonomic investigation and its taxonomic status be reviewed. We expect that the transcriptome assembly metrics can be useful for comparing other transcriptome assemblies of non-model organisms.

Association of Three Different Mutations in the CLCN1 Gene Modulating the Phenotype in a Consanguineous Family with Myotonia Congenita.

Myotonia congenita is a genetic disease caused by mutations in the CLCN1 gene, which encodes for the major chloride skeletal channel ClC-1, involved in the normal repolarization of muscle action potentials and consequent relaxation of the muscle after contraction. Two allelic forms are recognized, depending on the phenotype and the inheritance pattern: the autosomal dominant Thomsen disease with milder symptoms and the autosomal recessive Becker disorder with a severe phenotype. Before the recent advances of molecular testing, the diagnosis and genetic counseling of families was a challenge due to the large number of mutations in the CLCN1 gene, found both in homozygous or in heterozygous state. Here, we studied a consanguineous family in which three members presented a variable phenotype of myotonia, associated to a combination of three different mutations in the CLCN1 gene. A pathogenic splicing site mutation which causes the skipping of exon 17 was present in homozygosis in one very severely affected son. This mutation was present in compound heterozygosis in the consanguineous parents, but interestingly it was associated to a different second variant in the other allele: c.1453 A > G in the mother and c.1842 G > C in the father. Both displayed variable, but less severe phenotypes than their homozygous son. These results highlight the importance of analyzing the combination of different variants in the same gene in particular in families with patients displaying different phenotypes. This approach may improve the diagnosis, prognosis, and genetic counseling of the involved families.

Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea)

BACKGROUND: Vibrio species display variable and plastic fitness strategies to survive and interact with multiple hosts, including marine aquaculture species that are severely affected by pathogenic Vibrios. The culturable Vibrio sp. strain ArtGut-C1, the focus of this study, provides new evidence of such phenotypic plasticity as it accumulates polyhydroxybutyrate (PHB), a biodegradable polymer with anti-pathogen activity, particularly in the marine larviculture phase. The strain was isolated from the gut of laboratory-reared Artemia individuals, the live diet and PHB carrier used in larviculture. Its main phenotypic properties, taxonomic status and genomic properties are reported based on the whole-genome sequencing. RESULTS: Vibrio sp. ArtGut-C1 yielded 72.6% PHB of cells' dry weight at 25 C. The genomic average nucleotide identity (ANI) shows it is closely related to V. diabolicus (ANI: 88.6%). Its genome contains 5,236,997- bp with 44.8% GC content, 3,710 protein-coding sequences, 96 RNA, 9 PHB genes functionally related to PHB metabolic pathways, and several genes linked to competing and colonizing abilities. CONCLUSIONS: This culturable PHB-accumulating Vibrio strain shows high genomic and phenotypic variability. It may be used as a natural pathogen biocontrol in the marine hatchery and as a potential cell factory for PHB production.

The molecular landscape of osteogenesis imperfecta in a Brazilian tertiary service cohort.

We have sought the molecular diagnosis of OI in 38 Brazilian cases through targeted sequencing of 15 candidate genes. While 71% had type 1 collagen-related OI, defects in FKBP10, PLOD2 and SERPINF1, and a potential digenic P3H1/WNT1 interaction were prominent causes of OI in this underrepresented population. INTRODUCTION: Defects in type 1 collagen reportedly account for 85-90% of osteogenesis imperfecta (OI) cases, but most available molecular data has derived from Sanger sequencing-based approaches in developed countries. Massively parallel sequencing (MPS) allows for systematic and comprehensive analysis of OI genes simultaneously. Our objective was to obtain the molecular diagnosis of OI in a single Brazilian tertiary center cohort. METHODS: Forty-nine individuals (84% adults) with a clinical diagnosis of OI, corresponding to 30 sporadic and 8 familial cases, were studied. Sixty-three percent had moderate to severe OI, and consanguinity was common (26%). Coding regions and 25-bp boundaries of 15 OI genes (COL1A1, COL1A2, IFITM5 [plus 5'UTR], SERPINF1, CRTAP, P3H1, PPIB, SERPINH1, FKBP10, PLOD2, BMP1, SP7, TMEM38B, WNT1, CREB3L1) were analyzed by targeted MPS and variants of interest were confirmed by Sanger sequencing or SNP array. RESULTS: A molecular diagnosis was obtained in 97% of cases. COL1A1/COL1A2 variants were identified in 71%, whereas 26% had variants in other genes, predominantly FKBP10, PLOD2, and SERPINF1. A potential digenic interaction involving P3H1 and WNT1 was identified in one case. Phenotypic variability with collagen defects could not be explained by evident modifying variants. Four consanguineous cases were associated to heterozygous COL1A1/COL1A2 variants, and two nonconsanguineous cases had compound PLOD2 heterozygosity. CONCLUSIONS: Novel disease-causing variants were identified in 29%, and a higher proportion of non-collagen defects was seen. Obtaining a precise diagnosis of OI in underrepresented populations allows expanding our understanding of its molecular landscape, potentially leading to improved personalized care in the future.

Genomic and phenotypic diversity of Streptococcus mutans.

BACKGROUND: Streptococcus mutans (S. mutans) is a commensal microorganism found in the human oral cavity. However, due to environmental changes, selective pressures, and the presence of a variable genome, it adapts and may acquire new physiological and metabolic properties that alter dental biofilm homeostasis, promoting the development of dental caries. Although the plasticity and heterogeneity of S. mutans is widely recognized, very little is known about the mechanisms for the expression of pathogenic properties in specific genotypes. HIGHLIGHT: The implementation of molecular biology techniques in the study of S. mutans has provided information on the genomic diversity of this species. This variability is generated by genome rearrangements, natural genetic transformation, and horizontal gene transfer, and continues to grow due to an open pan-genome. The main virulence factors associated with the cariogenic potential of S. mutans include adhesion, acid production (acidogenicity), and acid tolerance (aciduricity), and also show variability. These factors coordinate the modification of the physicochemical properties of the biofilm, which results in the accumulation of S. mutans and other acidogenic and aciduric species in the oral cavity. CONCLUSION: We review the current literature on the main processes that generate S. mutans genomic diversity, as well as the phenotypic variability of its main virulence factors. S. mutans achieves its pathogenesis by sensing the intra- and extracellular environments and regulating gene transcription according to perceived environmental modifications. Consequently, this regulation gives rise to differential synthesis of proteins, allowing this species to potentially express virulence factors.

Intraspecific and interspecific trait variability in tadpole meta-communities from the Brazilian Atlantic rainforest.

A better understanding of species coexistence and community dynamics may benefit from more insights on trait variability at the individual and species levels.Tadpole assemblages offer an excellent system to understand the relative influence of intraspecific and interspecific variability on community assembly, due to their high phenotypic plasticity, and the strong influence that environmental variables have on their spatial distribution and individual performance.Here, we quantified the intraspecific and interspecific components of tadpoles' trait variability in order to investigate their relative role in shaping tadpole communities.We selected eight functional traits related to microhabitat use, foraging strategies, and swimming ability. We measured these traits on 678 individuals from 22 species captured in 43 ponds in the Atlantic Forest. We used single- and multitrait analyses to decompose trait variability. To explore the action of external and internal filtering on community assembly, we used a variance decomposition approach that compares phenotypic variability at the individual, population, community and regional levels.On average, 33% of trait variability was due to within-species variation. This decomposition varied widely among traits. We found only a reduced effect of external filtering (low variation in the height of the ventral fin within ponds in comparison to the total variation), whereas the internal filtering was stronger than expected. Traits related to the use of different microhabitats through the water column were generally less variable than traits related to swimming ability to escape of predators, with tail traits being highly variable within species.Our study highlights the importance of incorporating both intraspecific and interspecific, trait differences and of focusing on a diversity of traits related to both stabilizing niche and fitness differences in order to better understand how trait variation relates to species coexistence.

Split and Merge Watershed: a two-step method for cell segmentation in fluorescence microscopy images.

The development of advanced techniques in medical imaging has allowed scanning of the human body to microscopic levels, making research on cell behavior more complex and more in-depth. Recent studies have focused on cellular heterogeneity since cell-to-cell differences are always present in the cell population and this variability contains valuable information. However, identifying each cell is not an easy task because, in the images acquired from the microscope, there are clusters of cells that are touching one another. Therefore, the segmentation stage is a problem of considerable difficulty in cell image processing. Although several methods for cell segmentation are described in the literature, they have drawbacks in terms of over-segmentation, under-segmentation or misidentification. Consequently, our main motivation in studying cell segmentation was to develop a new method to achieve a good tradeoff between accurately identifying all relevant elements and not inserting segmentation artifacts. This article presents a new method for cell segmentation in fluorescence microscopy images. The proposed approach combines the well-known Marker-Controlled Watershed algorithm (MC-Watershed) with a new, two-step method based on Watershed, Split and Merge Watershed (SM-Watershed): in the first step, or split phase, the algorithm identifies the clusters using inherent characteristics of the cell, such as size and convexity, and separates them using watershed. In the second step, or the merge stage, it identifies the over-segmented regions using proper features of the cells and eliminates the divisions. Before applying our two-step method, the input image is first preprocessed, and the MC-Watershed algorithm is used to generate an initial segmented image. However, this initial result may not be suitable for subsequent tasks, such as cell count or feature extraction, because not all cells are separated, and some cells may be mistakenly confused with the background. Thus, our proposal corrects this issue with its two-step process, reaching a high performance, a suitable tradeoff between over-segmentation and under-segmentation and preserving the shape of the cell, without the need of any labeled data or relying on machine learning processes. The latter is advantageous over state-of-the-art techniques that in order to achieve similar results require labeled data, which may not be available for all of the domains. Two cell datasets were used to validate this approach, and the results were compared with other methods in the literature, using traditional metrics and quality visual assessment. We obtained 90% of average visual accuracy and an F-index higher than 80%. This proposal outperforms other techniques for cell separation, achieving an acceptable balance between over-segmentation and under-segmentation, which makes it suitable for several applications in cell identification, such as virus infection analysis, high-content cell screening, drug discovery, and morphometry.

Ontogenetic Change in the Venom of Mexican Black-Tailed Rattlesnakes (Crotalus molossus nigrescens).

Ontogenetic changes in venom composition have important ecological implications due the relevance of venom in prey acquisition and defense. Additionally, intraspecific venom variation has direct medical consequences for the treatment of snakebite. However, ontogenetic changes are not well documented in most species. The Mexican Black-tailed Rattlesnake (Crotalus molossus nigrescens) is large-bodied and broadly distributed in Mexico. To document venom variation and test for ontogenetic changes in venom composition, we obtained venom samples from twenty-seven C. m. nigrescens with different total body lengths (TBL) from eight states in Mexico. The primary components in the venom were detected by reverse-phase HPLC, western blot, and mass spectrometry. In addition, we evaluated the biochemical (proteolytic, coagulant and fibrinogenolytic activities) and biological (LD50 and hemorrhagic activity) activities of the venoms. Finally, we tested for recognition and neutralization of Mexican antivenoms against venoms of juvenile and adult snakes. We detected clear ontogenetic venom variation in C. m. nigrescens. Venoms from younger snakes contained more crotamine-like myotoxins and snake venom serine proteinases than venoms from older snakes; however, an increase of snake venom metalloproteinases was detected in venoms of larger snakes. Venoms from juvenile snakes were, in general, more toxic and procoagulant than venoms from adults; however, adult venoms were more proteolytic. Most of the venoms analyzed were hemorrhagic. Importantly, Mexican antivenoms had difficulties recognizing low molecular mass proteins (<12 kDa) of venoms from both juvenile and adult snakes. The antivenoms did not neutralize the crotamine effect caused by the venom of juveniles. Thus, we suggest that Mexican antivenoms would have difficulty neutralizing some human envenomations and, therefore, it may be necessary improve the immunization mixture in Mexican antivenoms to account for low molecular mass proteins, like myotoxins.

Phenotypic Variability in a Mexican Mestizo Family with Retinal Vasculopathy with Cerebral Leukodystrophy and TREX1 Mutation p.V235Gfs*6.

BACKGROUND: Retinal vasculopathy with cerebral leukodystrophy (RVCL) is an adult-onset, autosomal dominant disease involving microvessels of the brain and eye resulting in central nervous system degeneration with visual disturbances, stroke, motor impairment, and cognitive decline. Frameshift mutations at the C-terminus of TREX1 gene are the molecular cause of this disorder. OBJECTIVES: The objective of this study is to present the different clinical manifestations of RVCL in three-related patients and to investigate the presence of TREX1 mutation in the extended genealogy. METHODS: Multidisciplinary testing was performed in three related patients. Based on their family history, the study was extended to 34 relatives from the same small community. Neurological evaluation, sequencing of TREX1, and presymptomatic diagnosis were offered to all participants. RESULTS: The patients exhibited the heterozygous TREX1 mutation p.V235Gfs*6, but with phenotypic variability. In addition, 15 relatives were identified as pre-manifest mutation carriers. The remaining participants did not carry the mutation. CONCLUSIONS: This is the figrst report of a large Mexican genealogy with RVCL, where the same TREX1 mutation causes a variation in organ involvement and clinical progression. The early identification and follow-up of individuals at risk may help provide insights into the basis for this variability in presentation.

Variability in DNA Repair Capacity Levels among Molecular Breast Cancer Subtypes: Triple Negative Breast Cancer Shows Lowest Repair.

Breast cancer (BC) is a heterogeneous disease which many studies have classified in at least four molecular subtypes: Luminal A, Luminal B, HER2-Enriched, and Basal-like (including triple-negative breast cancer, TNBC). These subtypes provide information to stratify patients for better prognostic predictions and treatment selection. Individuals vary in their sensitivities to carcinogens due to differences in their DNA repair capacity (DRC) levels. Although our previous case-control study established low DRC (in terms of NER pathway) as a BC risk factor, we aim to study this effect among the molecular subtypes. Therefore, the objectives of this study include investigating whether DRC varies among molecular subtypes and testing any association regarding DRC. This study comprised 267 recently diagnosed women with BC (cases) and 682 without BC (controls). Our results show a substantial variability in DRC among the molecular subtypes, with TNBC cases (n = 47) having the lowest DRC (p-value < 0.05). Almost 80 percent of BC cases had a DRC below the median (4.3%). Low DRC was strongly associated with the TNBC subtype (OR 7.2; 95% CI 3.3, 15.7). In conclusion, our study provides the first report on the variability among the molecular subtypes and provides a hypothesis based on DRC levels for the poor prognosis of TNBC.

Phenotypic variability and heritability of the cephalic region of Caiman latirostris.

The study of the cephalic shape of crocodilian is relevant in the fields of ecology, systematics, evolution, and conservation. Therefore, the integration of geometric analysis within quantitative genetics allows the evaluation of the inheritable shape components. In this study, the dorsal cephalic region of 210 Caiman latirostris hatchlings was analyzed from seven populations in Santa Fe, Argentina, to detect intra-, and inter-population phenotypic variability, and to determine the heritability of biological shape and size, using newly available geometric morphometric tools. The principal component analysis showed two configurations of cephalic shape that could be related to sexual dimorphism. In the canonical variate analysis, Procrustes distances between groups indicated that there are differences in shape among populations. Furthermore, the method of partial least squares indicated a covariation between cephalic shape and environmental variables. Regarding to CS of the skull we found significant differences among populations, moreover the partial least squares was also significant. Estimates of the heritability of shape and size were high, indicating that the components of these features are susceptible to the selection.

Functional traits variation explains the distribution of Aextoxicon punctatum (Aextoxicaceae) in pronounced moisture gradients within fog-dependent forest fragments.

Climate change and fragmentation are major threats to world forests. Understanding how functional traits related to drought tolerance change across small-scale, pronounced moisture gradients in fragmented forests is important to predict species' responses to these threats. In the case of Aextoxicon punctatum, a dominant canopy tree in fog-dependent rain forest patches in semiarid Chile, we explored how the magnitude, variability and correlation patterns of leaf and xylem vessel traits and hydraulic conductivity varied across soil moisture (SM) gradients established within and among forest patches of different size, which are associated with differences in tree establishment and mortality patterns. Leaf traits varied across soil-moisture gradients produced by fog interception. Trees growing at drier leeward edges showed higher leaf mass per area, trichome and stomatal density than trees from the wetter core and windward zones. In contrast, xylem vessel traits (vessels diameter and density) did not vary producing loss of hydraulic conductivity at drier leeward edges. We also detected higher levels of phenotypic integration and variability at leeward edges. The ability of A. punctatum to modify leaf traits in response to differences in SM availability established over short distances (<500 m) facilitates its persistence in contrasting microhabitats within forest patches. However, xylem anatomy showed limited plasticity, which increases cavitation risk at leeward edges. Greater patch fragmentation, together with fluctuations in irradiance and SM in small patches, could result in higher risk of drought-related tree mortality, with profound impacts on hydrological balances at the ecosystem scale.