Karyotypic study of some species of Serjania and Urvillea (Sapindaceae; Tribe Paullinieae)

Karyotypes of six species (in ten populations) of the genus Serjania and one species of the genus Urvillea were studied using root tip mitotic metaphases. All species of Serjania were diploids with 2n = 24 chromosomes and the species of Urvillea was octoploid with 2n = 86 chromosomes. Analysis of the karyotypes of Serjania showed that the species are differentiated by chromosomic structural changes. Chromosome lengths showed great differences among the species that may be explained by chromosomal deletion or addition. The basic chromosomic number is x = 12 for Serjania and x = 11 for Urvillea. In Urvillea the evolutionary trend may be toward polyploidy followed by reductional aneuploidy. The Giemsa (C-band) staining technique was applied in Serjania; however, no clear blocks of heterochromatin were observed. This result agrees with the presence of semireticulate nuclei. The Nucleolar Organizing Region (NOR-banding) technique was applied in S. communis and S. laruotteana, which showed one and two pairs stained, respectively. Variation in the number of nucleoli was observed among the different populations of Serjania. This variation could be explained by the presence of small nucleolar organizer regions that occur scattered along the genome and are not detected by the silver staining methodology.     

Inhibition of PARP activity by PJ‐34 leads to growth impairment and cell death associated with aberrant mitotic pattern and nucleolar actin accumulation in M14 melanoma cell line

The capability of PARP activity inhibitors to prevent DNA damage recovery suggested the use of these drugs as chemo‐ and radio‐sensitisers for cancer therapy. Our research, carried out on cultured human M14 melanoma cells, was aimed to examine if PJ‐34, a potent PARP activity inhibitor of second generation, was per se able to affect the viability of these cancer cells without any DNA damaging agents. Using time‐lapse videomicroscopy, we evidenced that 10 µM PJ‐34 treatment induced severe mitotic defects leading to dramatic reduction of cell proliferation and to cell death. PJ‐34 cytotoxic effect was further confirmed by analysis of cell viability and clonogenic assay. Absence of canonic apoptosis markers allowed us to exclude this kind of cell death. No single and/or double stranded DNA damage was evidenced. Immunofluorescence analysis showed an aberrant mitotic scenario in several cells and subsequent multinucleation suggesting an atypical way for cells to die: the mitotic catastrophe. The detection of aberrant accumulation of polymerised actin inside the nucleolus was noteworthy. Taken toghether, our results demonstrate that, targeting PARP activity by PJ‐34, cancer cell survival is affected independently of DNA damage repair. Two findings are remarkable: (a) cisplatin concentration can be reduced by three quarters if it is followed by treatment with 10 µM PJ‐34 for 24 h to obtain the same citotoxic effect; (b) effects dependent on PJ‐34 treatment are reversible. Our data suggest that, to reduce the harm done to non‐tumour cells during chemotherapy with cisplatin, the latter could be coupled with PJ‐34 treatment. J. Cell. Physiol. 222: 401–410, 2010. © 2009 Wiley‐Liss, Inc.     

Cerapeplus gen.n. and the classification of micropeplids (Coleoptera: Micropeplidae)

Cerapeplus siamensis gen.n., sp.n. from Thailand is described and illustrated. The new genus is characterized by filament-based lamellar secretions arising from the lateral body margin, a feature observed for the first time in Coleoptera. Possible autapomorphies for the micropeplid genera are discussed. It is concluded that Cerapeplus and Kalissus are monophyletic; Micropeplus and/Or Peplomicrus are probably polyphyletic but both genera together form a monophyletic group. A number of characters support the family status of the micropeplids recently proposed by some authors. A revised family diagnosis is provided.     

Molecular tools confirm natural Leishmania (Viannia) guyanensis/L. (V.) shawi hybrids causing cutaneous leishmaniasis in the Amazon region of Brazil

Seven isolates from patients with American cutaneous leishmaniasis in the Amazon region of Brazil were phenotypically suggestive of Leishmania (Viannia) guyanensis/L. (V.) shawi hybrids. In this work, two molecular targets were employed to check the hybrid identity of the putative hybrids. Heat shock protein 70 (hsp70) gene sequences were analyzed by three different polymerase chain reaction (PCR) approaches, and two different patterns of inherited hsp70 alleles were found. Three isolates presented heterozygous L. (V.) guyanensis/L. (V.) shawi patterns, and four presented homozygous hsp70 patterns involving only L. (V.) shawi alleles. The amplicon sequences confirmed the RFLP patterns. The high-resolution melting method detected variant heterozygous and homozygous profiles. Single-nucleotide polymorphism genotyping/cleaved amplified polymorphic site analysis suggested a higher contribution from L. (V.) guyanensis in hsp70 heterozygous hybrids. Additionally, PCR-RFLP analysis targeting the enzyme mannose phosphate isomerase (mpi) gene indicated heterozygous and homozygous cleavage patterns for L. (V.) shawi and L. (V.) guyanensis, corroborating the hsp70 findings. In this communication, we present molecular findings based on partial informative regions of the coding sequences of hsp70 and mpi as markers confirming that some of the parasite strains from the Brazilian Amazon region are indeed hybrids between L. (V.) guyanensis and L. (V.) shawi.     

Histopathological changes in zebrafish exposed to sublethal concentrations of 89 nm silver nanoparticles for application in environmental diagnostics

Abstract

The use of biomarkers as indicators of environmental contamination has been shown to be an excellent indicator of changes in biota. Histopathological lesions are commonly used in biomonitoring studies as they provide information regarding both acute and chronic exposure. The use of nanoparticle materials has been widespread in recent years. However, not much is known about their ecological effects on the natural environment. Thus, the aim of this study was to assess the sublethal effects of silver nanoparticles (AgNP) with mean diameters of 89?nm in the zebrafish Danio rerio by the determination of the LC₅₀; 48?h and histopathological assays in gills. The obtained LC₅₀; 48?h was 8.18 µgL^?1. The histopathological gill assessment showed primary responses indicative of acute damage as aneurysms (32.76%), hyperplasia (20.69%) and partial (30.17%) and total lamellar fusion (6.9%) of secondary lamellae. No deposition of AgNP was observed in any tested sample gills, suggesting other organs target to absorption and detoxification. In fact, the AgNP causes sublethal damage in the gills of zebrafish but is not able to accumulate in this tissue. Finally, the data shown in this study contribute to the construction of a database on the AgNP exposure in aquatic organisms.     

PCR primers specific for the genus Tuber reveal the presence of several truffle species in a truffle-ground

Truffles are hypogeous Ascomycete fungi belonging to the genus Tuber and forming fruiting bodies highly prized for their taste and aroma. The identification of the genus Tuber and its species is important to investigate their ecology and avoid fraud in the food market. As genus-specific primers are not available, the aims of this work were (1) to assess the usefulness of the β-tubulin gene as a DNA barcoding region for designing Tuber genus-specific primers, (2) to test the primers on a range of fruiting bodies, representing a large part of truffle biodiversity and (3) to check their ecological usefulness, applying them to truffle-ground soil. The new primers designed on the β-tubulin gene were specific to the Tuber genus in nested PCR. When applied to DNA from soils, they gave a positive signal for 23 of 32 soils. Phylogenetic analysis confirmed that the bands corresponded to Tuber and that at least five Tuber species were present in the truffle-ground. β-tubulin was found to be a good barcoding region for designing Tuber genus-specific primers, detecting a high Tuber diversity in a natural environment. These primers will be useful for understanding truffle ecology and for practical needs in plantation management.