Environmental patterns of adaptation after range expansion in Leontodon longirostris: The effect of phenological events on fitness-related traits.

PREMISE: Because of expected range shifts associated with climate change, there is a renewed interest in the evolutionary factors constraining adaptation, among which are genetic bottlenecks, drift, and increased mutational load after range expansion. Here we study adaptation in the short-lived species Leontodon longirostris showing reduced genetic diversity and increased genetic load along an expansion route. METHODS: We assessed the phenological patterns of variation, and their effect on fitness-related traits, on 42 L. longirostris populations and six populations of the sister taxa L. saxatilis in a common garden located within the current range of both species. The comparison among L. longirostris populations allowed us to test for genetic clines consistent with local adaptation, whereas the comparison between taxa provided evidence for common adaptive features at the species level. RESULTS: We found significant within-species variability for most traits, as well as differences with its close relative L. saxatilis. In general, seeds from drier, warmer, and unpredictable habitats showed overall lower and more restricted conditions for germination, seedlings emerged later and plants flowered earlier. Consequently, genotypes from arid and unpredictable environments attained smaller reproductive sizes and allocated more biomass to reproduction. Flowering time had the strongest direct effect on total plant size, but seedling emergence also showed an important indirect effect. CONCLUSIONS: Our results show the crucial role of phenological patterns in shaping adaptive clines for major life-history stage transitions. Furthermore, the genetic load observed in L. longirostris does not seem to preclude adaptation to the climatic variability encountered along the expansion route.

Demography, genetic diversity and expansion load in the colonizing species Leontodon longirostris (Asteraceae) throughout its native range.

Unravelling the evolutionary processes underlying range expansions is fundamental to understand the distribution of organisms, as well as to predict their future responses to environmental change. Predictions for range expansions include a loss of genetic diversity and an accumulation of deleterious alleles along the expansion axis, which can decrease fitness at the range-front (expansion load). In plants, empirical studies supporting expansion load are scarce, and its effects remain to be tested outside a few model species. Leontodon longirostris is a colonizing Asteraceae with a widespread distribution in the Western Mediterranean, providing a particularly interesting system to gain insight into the factors that can enhance or mitigate expansion load. In this study, we produced a first genome draft for the species, covering 418 Mbp (~53% of the genome). Although incomplete, this draft was suitable to design a targeted sequencing of ~1.5 Mbp in 238 L. longirostris plants from 21 populations distributed along putative colonization routes in the Iberian Peninsula. Inferred demographic history supports a range expansion from southern Iberia around 40,000 years ago, reaching northern Iberia around 25,000 years ago. The expansion was accompanied by a loss of genetic diversity and a significant increase in the proportion of putatively deleterious mutations. However, levels of expansion load in L. longirostris were smaller than those found in other plant species, which can be explained, at least partially, by its high dispersal ability, the self-incompatible mating system, and the fact that the expansion occurred along a strong environmental cline.

Environmental differences are correlated with the distribution pattern of cytotypes in Veronica subsection Pentasepalae at a broad scale.

BACKGROUND AND AIMS: The distribution of cytotypes and its potential correlation with environmental variables represent a cornerstone to understanding the origin and maintenance of polyploid lineages. Although many studies have addressed this question in single species at a regional scale, only a few have attempted to decipher this enigma in groups of closely related species at a broad intercontinental geographical scale. Here, we consider approx. 20 species of a diploid-polyploid complex (Veronica subsect. Pentasepalae) of recent and rapid diversification represented in Europe and North Africa to study the frequency and distribution of cytotypes and their relationship to environmental variables. METHODS: A total of 680 individuals (207 populations) were sampled. Ploidy levels were determined using flow cytometry. Ecological differentiation among cytotypes was tested using climatic and environmental variables related to temperature, precipitation, vegetation and biogeographical region, among others, and by performing univariate and multivariate (constrained principal coordinates analysis) analyses. KEY RESULTS: Four ploidy levels (2x, 4x, 6x and 8x) were found and genome downsizing was observed to occur within the group. Plants of different ploidy level are ecologically differentiated, with hexaploids and octoploids occurring in wetter and colder habitats with a higher seasonality than diploids. A south to north distribution pattern was found, with diploids occupying southern refugial areas and octoploids being more frequent in northern regions of Europe above the permafrost boundary. CONCLUSIONS: The distribution of cytotypes can be explained by ecological differentiation, the geographical position of refuge areas during the Quaternary climatic oscillations as well as by ice and permafrost retreat patterns. The Balkan Peninsula constitutes the most important contact zone between cytotypes. This work provides the first comprehensive ploidy screening within V. subsect. Pentasepalae at a broad scale and indicates that polyploidy and genome downsizing might have contributed to the colonization of new habitats in a recently diverged polyploid complex.

Profilin-mediated food-induced allergic reactions are associated with oral epithelial remodeling.

BACKGROUND: In areas of high exposure to grass pollen, allergic patients are frequently sensitized to profilin, and some experience severe profilin-mediated food-induced reactions. This specific population of patients is ideal to study the relationship between respiratory and food allergies. OBJECTIVE: We sought to determine the role of oral mucosal epithelial barrier integrity in profilin-mediated allergic reactions. METHODS: Thirty-eight patients with profilin allergy stratified into mild or severe according to their clinical history and response to a profilin challenge test and 6 nonallergic subjects were recruited. Oral mucosal biopsies were used for measurement of CD11c, CD3, CD4, tryptase, claudin-1, occludin, E-cadherin, and vascular endothelial growth factor A levels; Masson trichrome staining; and POSTN, IL33, TPSAB, TPSB, and CMA gene expression analysis by using quantitative RT-PCR. Blood samples were used for basophil activation tests. RESULTS: Distinct features of the group with severe allergy included the following: (1) impaired epithelial integrity with reduced expression of claudin-1, occludin, and E-cadherin and decreased numbers of epithelial cells, which is indicative of acanthosis, higher collagen deposition, and angiogenesis; (2) inflammatory immune response in the mucosa, with an increased number of CD11c+ and CD4+ infiltrates and increased expression of the cytokine genes POSTN and IL33; and (3) a 10-fold increased sensitivity of basophils to profilin. CONCLUSIONS: Patients with profilin allergy present with significant damage to the oral mucosal epithelial barrier, which might allow profilin penetration into the oral mucosa and induction of local inflammation. Additionally, severely allergic patients presented with increased sensitivity of effector cells.

Carcinoma epidermoide oral alrededor de implantes osteointegrados: a propósito de un caso y revisión bibliográfica / Squamous cell carcinoma surrounding osseointegrated dental implants: clinical case and references review

Resumen Introducción La rehabilitación oral con implantes es en la actualidad la mejor opción para el tratamiento de pacientes parcial o totalmente edéntulos. Sin embargo, no es un procedimiento exento de complicaciones. La aparición de carcinoma epidermoide en la encía circundante de los implantes, aunque infrecuente puede ser una de ellas y aunque no hay muchos casos descritos en la literatura, sería conveniente establecer qué relación, si es que existiera, pueden tener los implantes en el desarrollo de esta enfermedad. Caso clínico Presentamos el caso de una mujer de 85 años de edad con antecedentes personales de liquen plano oral, exfumadora y portadora de implantes osteointegrados colocados en las áreas correspondientes a 34, 45 y 46, que desarrolló un carcinoma epidermoide en la encía periimplantaria.

Introduction Currently, dental implants is considered as the best choice for edentulism partial or complete treatment. However, this treatment has some associated medical complications such as surrounding gum squamous cell carcinoma. Even though there are not that many cases described in medical literature, it could be appropriated to determine whether there is any relation between this neoplasic disease and the dental implants. Clinical case Presenting a 85-year-old women with PMH of lichen planus, ex-smoker and osseointegrated dental implant in areas 34, 45 and 46, with surrounding implant gum area Squamous cell carcinoma.

Correlation between single photon emission computed tomography and histopathologic findings in condylar hyperplasia of the temporomandibular joint.

PURPOSE: To analyse the correlation between the level of activity measured in the single photon emission computed tomography (SPECT) and the pathological findings in patients with condylar hyperplasia (CH). MATERIALS AND METHODS: All patients evaluated in our department between 2007 and 2014 with a diagnosis of condylar hyperplasia who had undergone SPECT, evidenced signs of activity, and had undergone surgery were included. We included 28 patients, of whom 20 were women and 8 men. RESULTS: The male:female ratio was 2,5:1. The mean age of the subjects was 24.4 years at the time of diagnosis (with a range between 14 and 42 years). In 19 cases the affected condyle was the right, and in the remaining 9 it was the left (ratio R:L 2,1:1). On the SPECT, in 16 patients a high level of activity was identified (57.1%) and in the remaining 12 a low level (42.9%). Only 13 patients (6 in the low-activity group and 7 in the high-activity group) presented with islands of cartilage. When comparing the results between the two groups, the main differences were observed in the parameters related to the islands of cartilage. These were more frequent in the group with high activity compared with low activity (5.5 versus 0 per mm2 of median). Besides being more frequent, these islands were larger (more than double) in the high-activity group (385.1 µm versus 169.7 µm of median). This is the only statistically significant difference found, a fact that can be explained by the small sample size in the study. CONCLUSION: Radioisotope tests are the best indicator of the level of activity in condylar hyperplasia, which seems to be directly related to the intensity signal collection.