Chromosome analysis of five Brazilian species of poison frogs (Anura: Dendrobatidae)

Dendrobatid frogs have undergone an extensive systematic reorganization based on recent molecular findings. The present work describes karyotypes of the Brazilian species Adelphobates castaneoticus, A. quinquevittatus, Ameerega picta, A. galactonotus and Dendrobates tinctorius which were compared to each other and with previously described related species. All karyotypes consisted of 2n = 18 chromosomes, except for A. picta which had 2n = 24. The karyotypes of the Adelphobates and D. tinctorius species were highly similar to each other and to the other 2n = 18 previously studied species, revealing conserved karyotypic characteristics in both genera. In recent phylogenetic studies, all Adelphobates species were grouped in a clade separated from the Dendrobates species. Thus, we hypothesized that their common karyotypic traits may have a distinct origin by chromosome rearrangements and mutations. In A. picta, with 2n = 24, chromosome features of pairs from 1 to 8 are shared with other previously karyotyped species within this genus. Hence, the A. picta data reinforced that the C-banding pattern and the NOR location are species-specific traits in the genus Ameerega. Moreover, the Ameerega monophyletism proposed by previous phylogenetic studies indicates that the karyotypic differences among species in this genus result from a long divergence time.     

Selective preying of the sphecid wasp Trachypus boharti on the meliponine bee Scaptotrigona postica: potential involvement of caste‐specific cuticular hydrocarbons

The specialist digger wasp Trachypus boharti Rubio‐Espina preys exclusively on males of the stingless bee Scaptotrigona postica Latreille 1807, although the hunting attacks involve both male and worker bees of S. postica and members of its own species. To understand the mechanism of prey selection, the cuticular hydrocarbon patterns of workers and males of S. postica are analyzed in detail, and the mandibular secretion of males is examined. The cuticular profiles of males and workers are distinctively different. The major group of cuticular compounds, heptacosene isomers, is twice as abundant in workers as in males. There is no clear distinction between worker and male mandibular secretions. Such a distinct and straightforward caste‐specific difference in cuticular hydrocarbons could function as a recognition cue by which T. boharti distinguishes between workers and males of S. postica.     

Endoglin based in vivo near-infrared fluorescence imaging of tumor models in mice using activatable liposomes

Background

Endoglin (CD105) is overexpressed on tumor cells and tumor vasculatures, making it a potential target for diagnostic imaging and therapy of different neoplasms. Therefore, studies on nanocarrier systems designed for endoglin-directed diagnostic and drug delivery purposes would expose the feasibility of targeting endoglin with therapeutics.

AIDS and associated malignancies

INTRODUCTION It has been over twenty years since the onset of the AIDS epidemic, and in spite of the tremendous progress made towards the understanding of the disease, the virus that causes the disease and the development of highly ef- fective anti-retrov…     

Molecular phylogeography of Carapichea ipecacuanha,an amphitropical shrub that occurs in the understory of both semideciduous and evergreen forests

The medicinal shrub Carapichea ipecacuanha (ipecac) is an amphitropic species with three disjunct areas of distribution. In the Brazilian Atlantic and Amazonian ranges, the species was associated mostly with the understory of seasonal semideciduous forests, whereas in the Central American–Colombian range, the species occurred in the understory of moist evergreen forests. We examined the phylogeographic structure of ipecac using chloroplast trnT‐trnL and nuclear internal transcribed spacer (ITS) sequences from 120 and 46 specimens, respectively. To complement existing data on root alkaloid profiles, we used high‐performance liquid chromatography to assess the levels of emetine and cephaeline in 33 specimens from the two Brazilian ranges. The three ranges shared neither nuclear nor chloroplast haplotypes. The phylogeographic structures showed an uneven distribution of genetic diversity, sharp breaks and high levels of genetic differentiation among ranges. Our results suggest that the extant populations are descendents of at least four distinct ancestral lineages. The Atlantic ipecacs showed higher levels of genetic diversity than ipecacs from the other two ranges; it is likely that they derive from two ancestral lineages, with long‐term persistence in that region. The Amazonian ipecacs were monomorphic with respect to the ITS and cpDNA sequences, which supports the view that there was a recent expansion from a single parental source after a strong genetic bottleneck. The existence of a fourth distinct lineage is apparent from the high levels of genetic and chemical differentiation that we identified in the Central American–Columbian ipecacs.