Functional connectivity and genetic diversity of Eulaema atleticana (Apidae,Euglossina) in the Brazilian Atlantic Forest Corridor: assessment of gene flow

The mobility and dispersal of organisms affect population genetics and dynamics, and consequently affect persistence and the risk of extinction. Thus, it is important to understand how organisms move in the fragmented landscapes in order to manage populations and predict the effects of habitat changes on species persistence. This study evaluated the functional connectivity of an orchid bee (Eulaema atleticana Nemésio, 2009) with a high fidelity to forest habitats in the Brazilian Atlantic Forest Corridor by analyzing genetic diversity, spatial genetic structure, and gene flow estimated from microsatellite and mitochondrial markers. Genetic diversity was not correlated with area of the forest fragments, or with forest isolation. At the mosaic scale, Eulaema atleticana showed no significant or low genetic differentiation, indicating genetic homogeneity among forest fragments. A previous field study indicated that Eulaema atleticana was one of the most sensitive Euglossina bees to forest fragmentation but the present molecular analyses demonstrates that current gene flow is sufficient to maintain genetic variability at the mosaic scale.     

A taxonomic revision of <Emphasis Type="Italic">Bursera</Emphasis> subgen. <Emphasis Type="Italic">Bursera</Emphasis> in the Greater Antilles and the Bahamas,including a new species from Cuba

A revision of Bursera in the Greater Antilles and the Bahamas has confirmed that Commiphora does not occur in the region and that all but one species in the region belong to Bursera subgen. Bursera. Here we describe a new species, Bursera yaterensis; B. nashii is synonymized with B. glauca and B. ovata is synonymized with B. trinitensis; and we return five species from Commiphora to Bursera. A dichotomous key is provided using mostly vegetative characters due to the frequent lack of adequate reproductive material and the relative uniformity of most floral and fruit characters.     

Geometric and traditional morphometrics for the assessment of character state identity: multivariate statistical analyses of character variation in the genus Arrenurus (Acari,Hydrachnidia, Arrenuridae)

Geometric and traditional morphometric approaches are tested to describe and reveal taxonomic characters and character states in variation of shape and size of idiosoma morphology in the Arrenuridae. Patterns of variation of idiosoma and glandularia features of males from 11 Mexican species of Arrenurus (Megaluracarus) and two species of subgenus Dadayella were explored with five landmark configurations and three sets of interlandmark distances. Separate principal component analyses (PCA) and canonical variate analyses (CVA) were performed for each data set. The eight multivariate analyses of variance among 13 a priori groups (species) detected significantly different morphometric variants, which were interpreted as different taxonomic character states. Patterns of character state similarity among species were examined with unweighted‐pair grouping method using averages (UPGMA) cluster analyses on Mahalanobis distances. Analyses of five landmark configurations revealed important taxonomical variation in the anterior idiosoma outline (10 character states), the outline of the posterior region or cauda (13 states), the distribution of postocularia, and the second and third pairs of dorsoglandularia (nine states), the fourth pair of dorsoglandularia (three states), and ventroglandularia on the posterior side of idiosoma (nine character states). Multivariate analyses of three sets of distance measurements also resulted in the detection of potential taxonomic characters related to idiosoma size (12 character states), postocularia and dorsoglandularia (13 states), and ventroglandularia (nine character states). Morphometric analyses of distances and shapes provide a formal basis for the interpretation of taxonomic characters, and for the discovery of character states. These characters should be investigated further in a wider sample of species for the phylogenetic systematics of these water mites. In the meantime, idiosoma regions and structures were tested for congruence in a phylogenetic analysis, and were proposed as homologous among the species sampled.     

The formation of titan cells in Cryptococcus neoformans depends on the mouse strain and correlates with induction of Th2‐type responses

Cryptococcus neoformans is a pathogenic yeast that can form titan cells in the lungs, which are fungal cells of abnormal enlarged size. Little is known about the factors that trigger titan cells. In particular, it is not known how the host environment influences this transition. In this work, we describe the formation of titan cells in two mouse strains, CD1 and C57BL/6J. We found that the proportion of C. neoformans titan cells was significantly higher in C57BL/6J mice than in CD1. This higher proportion of titan cells was associated with a higher dissemination of the yeasts to the brain. Histology sections demonstrated eosinophilia in infected animals, although it was significantly lower in the CD1 mice which presented infiltration of lymphocytes. Both mouse strains presented infiltration of granulocytes, but the amount of eosinophils was higher in C57BL/6J. CD1 mice showed a significant accumulation of IFN‐γ, TNF‐α and IL17, while C57BL/BL mice had an increase in the anti‐inflammatory cytokine IL‐4. IgM antibodies to the polysaccharide capsule and total IgE were more abundant in the sera from C57BL/6J, confirming that these animals present a Th2‐type response. We conclude that titan cell formation in C. neoformans depends, not only on microbe factors, but also on the host environment.     

ApoE4 upregulates the activity of mitochondria‐associated ER membranes

In addition to the appearance of senile plaques and neurofibrillary tangles, Alzheimer''s disease (AD) is characterized by aberrant lipid metabolism and early mitochondrial dysfunction. We recently showed that there was increased functionality of mitochondria‐associated endoplasmic reticulum (ER) membranes (MAM), a subdomain of the ER involved in lipid and cholesterol homeostasis, in presenilin‐deficient cells and in fibroblasts from familial and sporadic AD patients. Individuals carrying the ε4 allele of apolipoprotein E (ApoE4) are at increased risk for developing AD compared to those carrying ApoE3. While the reason for this increased risk is unknown, we hypothesized that it might be associated with elevated MAM function. Using an astrocyte‐conditioned media (ACM) model, we now show that ER–mitochondrial communication and MAM function—as measured by the synthesis of phospholipids and of cholesteryl esters, respectively—are increased significantly in cells treated with ApoE4‐containing ACM as compared to those treated with ApoE3‐containing ACM. Notably, this effect was seen with lipoprotein‐enriched preparations, but not with lipid‐free ApoE protein. These data are consistent with a role of upregulated MAM function in the pathogenesis of AD and may help explain, in part, the contribution of ApoE4 as a risk factor in the disease.     

Synthesis,structure, antimycobacterial and anticancer evaluation of new pyrrolo-phenanthroline derivatives

A study concerning design, synthesis, structure and in vitro antimycobacterial and anticancer evaluation of new fused derivatives with pyrrolo[2,1-c][4,7]phenanthroline skeleton is described. The strategy adopted for synthesis involves a [3?+?2] dipolar cycloaddition of several in situ generated 4,7-phenanthrolin-4-ium ylides to different substituted alkynes and alkenes. Stereo- and regiochemistry of cycloaddition reactions were discussed. The structure of the new compounds was proven unambiguously, single-crystal X-ray diffraction studies including. The antimycobacterial and anticancer activity of a selection of new synthesized compounds was evaluated against Mycobacterium tuberculosis H37Rv under aerobic conditions and 60 human tumour cell line panel, respectively. Five of the tested compounds possess a moderate antimycobacterial activity, while two of the compounds have a significant antitumor activity against renal cancer and breast cancer.