Argyrophilic nucleolar organizer region (AgNOR) technique: a helpful tool for differential diagnosis in urinary cytology

The aim of this study was to investigate whether the AgNOR technique could be helpful for the cytologic diagnosis of neoplastic and non-neoplastic urinary tract lesions. We analysed the AgNOR pattern in urinary cytology in samples from 70 patients. In every case the average number of silver precipitations per nucleus was counted and the range between the minimum and maximum AgNOR value calculated. Furthermore we noted whether the AgNOR precipitations had a homogeneous or heterogeneous distribution. The diseases were classified in three groups: non-neoplastic lesions, low grade and high grade carcinoma. Linear discriminant analysis (with jack-knife procedure) was performed with the AgNOR parameters as independent variables. The final diagnosis of each patient had been established by histological analysis of bladder biopsies. We obtained a correct classification in 84.3% of the cases. All patients with normal or reactive lesions were correctly classified and only two cases of low grade malignancy were erroneously diagnosed as non-malignant. Five high grade neoplasms had been classified as low grade and four low grade carcinomas had been over-diagnosed as high grade neoplasms. We conclude that a combined qualitative and quantitative AgNOR analysis can be useful in the differential diagnosis of urinary cytology.     

Pigmentary System of the Adult Alpine Salamander Salamandra atra atra (Laur., 1768)

The pigmentary system of the skin from adult specimens of the black alpine salamander Salamandra atra atra was investigated by light microscope, electron microscope, and biochemical studies. Results were compared with those obtained in previous study of the subspecies Salamandra atra aurorae. Unlike Salamandra atra aurorae, which presents epidermal xanthophores and iridophores, Salamandra atra atra is completely melanized, presenting only epidermal and dermal melanophores. The melanosomes in both the epidermis and the dermis appear to derive from a multivesicular premelanosome similar to that in the goldfish, and the epidermal melanosomes are smaller than those in the dermis. Premelanosomes with an internal lamellar matrix were not observed. The biochemical results have shown that in the ethanol extracts obtained from the skin in toto and from the melanosomes, pteridines and flavins are always present and are the same as those extracted from the black skin areas of Salamandra atra aurorae.     

Genetic variation and its evolutionary implications in a Mediterranean island endemic lizard

The peculiar bioclimatic and geographic features of Corso–Sardinian islands may provide an ideal scenario for investigating microevolutionary processes, given their large heterogeneity of environments, which could affect dispersal and gene flow among populations, as well as processes of local adaptation. The genetic variation and differentiation among populations of the endemic lizard Archaeolacerta bedriagae were studied by allozyme electrophoresis at 20 presumptive loci. The genetic structure of this species is characterized by relatively high levels of polymorphism and low differentiation among populations. The pattern of genetic differentiation cannot be explained by genetic drift as a function of geographic distance. Genetic distance data show that genetic variation is distributed into three geographically coherent population groups and suggest a recent (Late Pleistocene) origin for the observed geographic fragmentation. The analysis of environmental correlates of allozymic variation indicates a strong correlation of the Idh-1 locus with climatic variables. The frequency of the Idh-1¹⁰⁶ allele is negatively correlated with annual temperature, and positively correlated with annual precipitation. In addition, the observed heterozygosity at this locus decreases towards more arid climatic regimes. The results obtained support the assumption of differential selection acting on Idh-1 allozymes under diverse climates. An association between Idh-1 allozymes and local bioclimatic regimes was also observed for the sympatric lizard Podarcis tiliguerta , suggesting a key role for such selective agents on Idh-1 polymorphism in these two Corso–Sardinian lacertids.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 661–676.     

Genetic structure of a natural population of the ectomycorrhizal fungus Suillus pungens

Sequence-based markers were developed to study the genetic structure and reproductive biology of the ectomycorrhizal fungus Suillus pungens Thiers & Smith in a Bishop pine ( Pinus muricata D. Don) forest. Six different basidiome genotypes were found in a 1200 m² area. Five of the six genotypes were represented by single basidiomes. The remaining genotype comprised 13 basidiomes and covered an area of at least 300 m², with maximum measured dimensions of 40 m and 14 m. This is the largest genet of an ectomycorrhizal fungus described to date, and is likely the result of vegetative growth, because analysis of single spore isolates eliminates the possibility of genetic identity resulting from either apomixis or fortuitously indistinguishable recombinant genotypes. Genetic analysis also shows that although out-crossing appears to predominate in the population, at least a low percentage (1·4%) of spores are secondarily homothallic.
The combination of extensive vegetative growth and abundant fruiting suggests S. pungens utilizes more carbon than might be expected for a species which accounts for <3% of the total ectomycorrhizal abundance at the site. Additional carbon might come from either more efficient host–fungus transfer, pooling of carbon from the roots of different host plants, or saprophytism.     

Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash

The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co‐evolved with EAB. Here, we employed high‐throughput high‐performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC‐PDA‐MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability.