A new species of Phyllotis (Rodentia,Cricetidae, Sigmodontinae) from Tucumán province,Argentina

A new species of rodent of the genus Phyllotis is described based in cranial and external morphology, as well as morphometric data. Additionally, sequences of the mitochondrial gene cytochrome-b were used to asses the phylogenetic relationships. We have compared our specimens with all the extant species of the genus Phyllotis and also with some species of related genera, particularly with the most similar and with those that occur in the province of Tucumán and northwestern Argentina. The new species is large compared to the average size of the genus, and can be easily distinguished from all other species essentially by coloration and by cranial morphology. It is closely related to the recently described P. anitae, and these two species are, in turn, sister to P. osilae. The only two localities where the new species has been found are in the Upper Montane Forests of the southern portion of the Yungas Ecoregion, in the province of Tucumán, Argentina.     

A review of research on Chinese <Emphasis Type="Italic">Tuber</Emphasis> species

Truffles are abundant in some regions of China. Nevertheless, it was not until the 1980s that Tuber species were discovered by Chinese mycologists. In recent years, international truffle markets have shown an increasing interest in the import of Chinese Tuber. These truffles serve as a complement to European truffles due to their lower prices and their greater availability in a deficit market. However, Chinese truffles have been the subject of fraudulent commercial practices, and these could have a negative effect on truffle culture. These concerns have been behind numerous recent studies designed to obtain detailed information about Chinese Tuber species. Unfortunately, many of these studies are not published in English, and are dispersed throughout the specific local or national bibliography and proceedings of specialized truffle conferences. In view of the need to expand current knowledge of Chinese Tuber species, we present a comprehensive summary of the taxonomy, ecology, mycorrhizae, genetics, biochemistry, and cultivation of Chinese Tuber species. We also provide a synthetic taxonomy and morphological characterization of 16 Chinese Tuber species in order to assist in their verification and monitoring.     

The costal skeleton of Homo antecessor: preliminary results

The Lower Pleistocene TD6 level at the Gran Dolina site in the Sierra de Atapuerca (Burgos, Spain) has yielded nine ribs that represent a minimum of three individuals of the species, Homo antecessor. We present a detailed morphological and metric study of these costal elements, including the siding and anatomical position of all of the rib remains. The adult or nearly adult ribs are also metrically compared with other fossil hominins and with modern comparative samples. The costal elements recovered to date from the TD6 level at Gran Dolina can neither confirm nor reject the hypothesis that H. antecessor had a large thorax, similar to that of Neandertals. However, the fragmentary evidence of the H. antecessor thoracic skeleton is not inconsistent with this suggestion based on other skeletal elements, such as clavicles.

Resumen

En el nivel TD6 del Pleistoceno inferior del yacimiento de Gran Dolina, en la Sierra de Atapuerca (Burgos, España) se han recuperado nueve costillas que pertenecen a un mínimo de tres individuos de la especie Homo antecessor. Presentamos un detallado estudio métrico y morfológico incluyendo el lado y la determinación anatómica. Las costillas pertenecientes a individuos adultos o casi adultos también son comparadas métricamente a muestras modernas de comparación y otros homininos fósiles. Basándonos en el registro de costillas de Homo antecessor recuperado hasta el momento no podemos probar ni refutar la hipótesis de que esta especie presentaba un tórax grande similar al de los Neandertales. Sin embargo, el registro de costillas no es inconsistente con la hipótesis de un tórax grande como sugiere la gran longitud de sus clavículas.     

Association of Hemolytic Activity of Pseudomonas entomophila,a Versatile Soil Bacterium,with Cyclic Lipopeptide Production

Pseudomonas entomophila is an entomopathogenic bacterium that is able to infect and kill Drosophila melanogaster upon ingestion. Its genome sequence suggests that it is a versatile soil bacterium closely related to Pseudomonas putida. The GacS/GacA two-component system plays a key role in P. entomophila pathogenicity, controlling many putative virulence factors and AprA, a secreted protease important to escape the fly immune response. P. entomophila secretes a strong diffusible hemolytic activity. Here, we showed that this activity is linked to the production of a new cyclic lipopeptide containing 14 amino acids and a 3-C₁₀OH fatty acid that we called entolysin. Three nonribosomal peptide synthetases (EtlA, EtlB, EtlC) were identified as responsible for entolysin biosynthesis. Two additional components (EtlR, MacAB) are necessary for its production and secretion. The P. entomophila GacS/GacA two-component system regulates entolysin production, and we demonstrated that its functioning requires two small RNAs and two RsmA-like proteins. Finally, entolysin is required for swarming motility, as described for other lipopeptides, but it does not participate in the virulence of P. entomophila for Drosophila. While investigating the physiological role of entolysin, we also uncovered new phenotypes associated with P. entomophila, including strong biocontrol abilities.Pseudomonas entomophila is a recently isolated Pseudomonas species that is closely related to the saprophytic soil bacterium Pseudomonas putida. It was initially characterized as a natural pathogen of Drosophila (63). Indeed, P. entomophila was first isolated from flies sampled in Guadeloupe, and it is highly pathogenic for Drosophila larvae and adults. P. entomophila can also effectively kill members of other insect orders (e.g., Bombyx mori, Anopheles gambiae), which makes it a new entomopathogenic bacterium. Its ability to infect and kill Drosophila melanogaster very efficiently after ingestion makes it an appropriate model for the study of host-pathogen interactions (38, 62, 63).In order to unravel features contributing to the entomopathogenic properties of P. entomophila, its genome was sequenced. The results suggest that this strain is a ubiquitous, metabolically versatile bacterium that may colonize diverse habitats, including soil, rhizosphere, and aquatic systems, as shown for P. putida KT2440 (62). However, in contrast to the P. putida genome, the P. entomophila genome contains many genes that are predicted to be important for virulence toward insects. Notably, P. entomophila could secrete many degradative enzymes (proteases and lipases), putative toxins, and secondary metabolites (62). Similar factors have been shown to play a key role in the virulence of other entomopathogenic bacteria like Photorhabdus and Xenorhabdus sp. (27, 29).Insertional mutagenesis allowed the identification of several P. entomophila genes required to infect and/or kill Drosophila. This analysis demonstrated that P. entomophila virulence is under the control of the GacS/GacA two-component system (62, 63), a global regulatory system which is known to control secondary metabolite production, protein secretion, and pathogenic abilities in gammaproteobacteria (37, 65). Another study indicates that P. entomophila can counteract the Drosophila gut immune response as a result of the secretion of an abundant protease, AprA, which degrades antimicrobial peptides produced by gut epithelia and thereby promotes bacterial persistence (38). However, an AprA-deficient mutant remains virulent to some extent, indicating that P. entomophila virulence is multifactorial, AprA being one virulence factor among others.The secretion of virulence factors is a common mechanism employed by pathogens to compromise host defenses. Several entomopathogenic bacteria (e.g., Photorhabdus luminescens) secrete toxins that allow them to impair host function (8). The starting point of this study was the observation that, in contrast to several other Pseudomonas strains, P. entomophila secretes a strong diffusible hemolytic activity (which is also controlled by the Gac system). This raises the possibility of a link between this hemolytic activity and the pathogenicity of P. entomophila for Drosophila. Indeed, bacterial hemolysins are exotoxins that attack blood cell membranes and cause cell rupture by poorly defined mechanisms. It was conceivable that this hemolytic activity could be a readout for the ability of P. entomophila to damage the epithelial cells of the Drosophila gut, which plays a crucial role in its virulence (10, 33, 63).In this study, the P. entomophila hemolytic factor was identified as a cyclic lipopeptide (CLP) whose structure was elucidated. CLPs are versatile molecules with antimicrobial, cytotoxic, and surfactant properties that are produced by members of the genera Bacillus, Serratia, Burkholderia, and Pseudomonas (31, 41, 43, 50). They are produced by a ribosome-independent mechanism that utilizes multifunctional enzymes called nonribosomal peptide synthetases (NRPSs) (42, 59). These NRPSs are composed of repeated amino acid activation modules containing domains for condensation, aminoacyl adenylation, and thiolation. Modules are responsible for activation and incorporation of amino acids into the growing peptide. A large number of prokaryotic and some eukaryotic organisms synthesize peptide metabolites via this nonribosomal mechanism of biosynthesis (42, 47).Several genes involved in P. entomophila lipopeptide production were identified, three of them encoding NRPSs. The physiological role of this lipopeptide was also investigated, and it does not seem to play a role in the process of virulence towards Drosophila and Dictyostelium or in the P. entomophila biocontrol activity that was uncovered by this study. This suggests that the lifestyle of this newly identified bacterium is probably quite versatile and that lipopeptide production could be required only under specific circumstances.     

Mitochondrial DNA patterns in the Iberian Northern plateau: Population dynamics and substructure of the Zamora province

Several studies have shown the importance of recent events in the configuration of the genetic landscape of a specific territory. In this context, due to the phenomena of repopulation and demographic fluctuations that took place in recent centuries, the Iberian Northern plateau is a very interesting case study. The main aim of this work is to check if recent population movements together with existing boundaries (geographical and administrative) have influenced the current genetic composition of the area. To accomplish this general purpose, mitochondrial DNA variations of 214 individuals from a population located in the Western region of the Iberian Northern plateau (the province of Zamora) were analyzed. Results showed a typical Western European mitochondrial DNA haplogroup composition. However, unexpected high frequencies of U5, HV0, and L haplogroups were found in some regions. The analyses of microdifferentiation showed that there are differences between regions, but no geographic substructure organization can be noticed. It can be stated that the differences observed in the genetic pool of the sampled area at regional level results from the mixture of different populations carrying new lineages into this area at different points in history. Am J Phys Anthropol 142:531–539, 2010. © 2010 Wiley‐Liss, Inc.     

The usefulness of caries frequency,depth, and location in determining cariogenicity and past subsistence: A test on early and later agriculturalists from the Peruvian coast

Dental markers have been used to unravel particularities of paleodiet, subsistence, social structure, and health. This article aims to compare oral pathology among four pre‐Columbian groups with different degrees of agricultural and socio‐cultural development but comparable ecological conditions who lived on the coastal desert of Peru. Three of these groups are assigned to distinct phases of the Formative Period (2500–1 BC), a time critical for our understanding of the development of agriculture and social complexity. The fourth group corresponds to the Late Intermediate Period (1000–1470 AD), when agriculture had its apogee and society was highly stratified. In this study we test whether there is an increase (1) in the frequency of carious lesions and (2) in caries depth, and (3) if there is a shift from occlusal to extra‐occlusal caries locations with the development of agriculture. Therefore, we analyze the frequencies of carious lesions and antemortem tooth loss (AMTL), the caries distributions by age, sex, and type of tooth, as well as the tissues affected by, and the location of the carious lesions. Since there are no significant differences in the frequencies of carious lesions and AMTL between the groups, we reject hypothesis 1. In contrast, caries depth does increase, and caries location changes from occlusal to extra‐occlusal sites with agricultural development. However, we can only corroborate hypothesis 2 and 3 when taking into consideration dental wear. Thus, we recommend that caries depth and locations should be used with evaluations of dental wear to reconstruct subsistence in ancient populations. Am J Phys Anthropol 143:75–91, 2010. © 2010 Wiley‐Liss, Inc.     

Characteristics of the rat cardiac sphingolipid pool in two mitochondrial subpopulations

Mitochondrial sphingolipids play a diverse role in normal cardiac function and diseases, yet a precise quantification of cardiac mitochondrial sphingolipids has never been performed. Therefore, rat heart interfibrillary mitochondria (IFM) and subsarcolemmal mitochondria (SSM) were isolated, lipids extracted, and sphingolipids quantified by LC-tandem mass spectrometry. Results showed that sphingomyelin (∼10,000 pmol/mg protein) was the predominant sphingolipid regardless of mitochondrial subpopulation, and measurable amounts of ceramide (∼70 pmol/mg protein) sphingosine, and sphinganine were also found in IFM and SSM. Both mitochondrial populations contained similar quantities of sphingolipids except for ceramide which was much higher in SSM. Analysis of sphingolipid isoforms revealed ten different sphingomyelins and six ceramides that differed from 16- to 24-carbon units in their acyl side chains. Sub-fractionation experiments further showed that sphingolipids are a constituent part of the inner mitochondrial membrane. Furthermore, inner membrane ceramide levels were 32% lower versus whole mitochondria (45 pmol/mg protein). Three ceramide isotypes (C₂₀-, C₂₂-, and C₂₄-ceramide) accounted for the lower amounts. The concentrations of the ceramides present in the inner membranes of SSM and IFM differed greatly. Overall, mitochondrial sphingolipid content reflected levels seen in cardiac tissue, but the specific ceramide distribution distinguished IFM and SSM from each other.     

The N-glycosylation of classical swine fever virus E2 glycoprotein extracellular domain expressed in the milk of goat

Classical swine fever virus (CSFV) outer surface E2 glycoprotein represents an important target to induce protective immunization during infection but the influence of N-glycosylation pattern in antigenicity is yet unclear. In the present work, the N-glycosylation of the E2-CSFV extracellular domain expressed in goat milk was determined. Enzymatic N-glycans releasing, 2-aminobenzamide (2AB) labeling, weak anion-exchange and normal-phase HPLC combined with exoglycosidase digestions and mass spectrometry of 2AB-labeled and unlabeled N-glycans showed a heterogenic population of oligomannoside, hybrid and complex-type structures. The detection of two Man₈GlcNAc₂ isomers indicates an alternative active pathway in addition to the classical endoplasmic reticulum processing. N-acetyl or N-glycolyl monosialylated species predominate over neutral complex-type N-glycans. Asn207 site-specific micro-heterogeneity of the E2 most relevant antigenic and virulence site was determined by HPLC-mass spectrometry of glycopeptides. The differences in N-glycosylation with respect to the native E2 may not disturb the main antigenic domains when expressed in goat milk.     

A peptide based on the pore-forming domain of pro-apoptotic poliovirus 2B viroporin targets mitochondria

Non-structural poliovirus 2B protein induces plasma membrane permeabilization and has been recently implicated in triggering apoptosis via the mitochondrial pathway. Here we describe that the pore-forming P3 peptide, based on the 2B amphipathic domain, translocates through the plasma membrane of culture cells and targets mitochondria. Cell permeabilization by P3 versions of different lengths, together with peptide uptake analyses supported an internalization mechanism dependent on P3 capacity to interact physically with lipid bilayers and establish permeating pores therein. Internalized P3 was found associated with mitochondria, but contrary to the parental 2B protein, the short peptide did not affect the morphology or cell distribution of these organelles, nor induced apoptosis. We conclude that P3 constitutes a mitochondriotropic sequence, which is however devoid of 2B pro-apoptotic activity.