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Rodrigues PC Aguiar O Serpieri F Lima AP Uetanebaro M Recco-Pimentel SM 《Journal of genetics》2011,90(1):31-37
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. 相似文献
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DIRK KOEDAM E. DAVID MORGAN TÚLIO M. NUNES EDA FLÁVIA L. R. A. PATRICIO VERA L. IMPERATRIZ‐ FONSECA 《Physiological Entomology》2011,36(2):187-193
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. 相似文献
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Background and aims: Recently we reported on a genetically predisposed protection from C-reactive protein (CRP) related mortality in dialysis patients carrying the functional CC-chemokine receptor 5 deletion 32 allele (CCR5Δ32) mutation. Since CCR5Δ32 is associated with a less pro-inflammatory immune response in mice, we hypothesized that the observed protection is (in part) due to a less pro-inflammatory cytokine profile. Methods: Cross-sectional observational study including 263 incident dialysis patients aged 18–70 years, without clinical signs of infection and/or acute vasculitis. TNF-α, IL-6, IL-10 and hsCRP levels were determined and studied in relation to the CCR5 genotype. Results: In the presence of elevated hsCRP, IL-6 concentration was higher irrespective of the CCR5 genotype. However, in patients with the CCR5 deletion, TNF-α did not differ in the presence/absence of elevated hsCRP and was not correlated with hsCRP levels in carriers of the CCR5Δ32 polymorphism. Conclusions: A possible underlying mechanism of the impact of CCR5Δ32 genotype on inflammation driven mortality in dialysis patients could be a reduced Th1 immune response as represented by decreased TNF-α levels. 相似文献
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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… 相似文献
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LUIZ ORLANDO DE OLIVEIRA ANA APARECIDA BANDINI ROSSI ERNANE RONIE MARTINS FLÁVIA REIS DE CARVALHO BATISTA ROBERTA SANTOS SILVA 《Molecular ecology》2010,19(7):1410-1422
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. 相似文献
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Muntinghe FL Abdulahad WH Huitema MG Damman J Seelen MA Lems SP Hepkema BG Navis G Westra J 《PloS one》2012,7(2):e31257