Mitochondrial DNA signals of late glacial recolonization of Europe from near eastern refugia

Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ～19-12 thousand years (ka) ago.     

Regulation of respiration in muscle cells in vivo by VDAC through interaction with the cytoskeleton and MtCK within Mitochondrial Interactosome

This review describes the recent experimental data on the importance of the VDAC-cytoskeleton interactions in determining the mechanisms of energy and metabolite transfer between mitochondria and cytoplasm in cardiac cells. In the intermembrane space mitochondrial creatine kinase connects VDAC with adenine nucleotide translocase and ATP synthase complex, on the cytoplasmic side VDAC is linked to cytoskeletal proteins. Applying immunofluorescent imaging and Western blot analysis we have shown that β2-tubulin coexpressed with mitochondria is highly important for cardiac muscle cells mitochondrial metabolism. Since it has been shown by Rostovtseva et al. that αβ-heterodimer of tubulin binds to VDAC and decreases its permeability, we suppose that the β-tubulin subunit is bound on the cytoplasmic side and α-tubulin C-terminal tail is inserted into VDAC. Other cytoskeletal proteins, such as plectin and desmin may be involved in this process. The result of VDAC-cytoskeletal interactions is selective restriction of the channel permeability for adenine nucleotides but not for creatine or phosphocreatine that favors energy transfer via the phosphocreatine pathway. In some types of cancer cells these interactions are altered favoring the hexokinase binding and thus explaining the Warburg effect of increased glycolytic lactate production in these cells. This article is part of a Special Issue entitled: VDAC structure, function, and regulation of mitochondrial metabolism.     

Identification and Validation of Human Papillomavirus Encoded microRNAs

We report here identification and validation of the first papillomavirus encoded microRNAs expressed in human cervical lesions and cell lines. We established small RNA libraries from ten human papillomavirus associated cervical lesions including cancer and two human papillomavirus harboring cell lines. These libraries were sequenced using SOLiD 4 technology. We used the sequencing data to predict putative viral microRNAs and discovered nine putative papillomavirus encoded microRNAs. Validation was performed for five candidates, four of which were successfully validated by qPCR from cervical tissue samples and cell lines: two were encoded by HPV 16, one by HPV 38 and one by HPV 68. The expression of HPV 16 microRNAs was further confirmed by in situ hybridization, and colocalization with p16INK4A was established. Prediction of cellular target genes of HPV 16 encoded microRNAs suggests that they may play a role in cell cycle, immune functions, cell adhesion and migration, development, and cancer. Two putative viral target sites for the two validated HPV 16 miRNAs were mapped to the E5 gene, one in the E1 gene, two in the L1 gene and one in the LCR region. This is the first report to show that papillomaviruses encode their own microRNA species. Importantly, microRNAs were found in libraries established from human cervical disease and carcinoma cell lines, and their expression was confirmed in additional tissue samples. To our knowledge, this is also the first paper to use in situ hybridization to show the expression of a viral microRNA in human tissue.     

Influence of land use on hyporheos in catchment streams of the Velka Fatra Mts

The historical influence of landscape on the quantitative variables and a special group of hyporheos in streams with similar origin but different catchment landscapes and forest management was studied. The study was conducted in two streams: (i) a preserved forested natural stream where critical ecosystem processes were unaltered by human activities and (ii) a stream with the strong anthropogenic stressors (e.g., logging, agriculture, pasture), impacting the system for the last 500 years. Some parameters were strongly related to these land use: conductivity, fine benthic organic matter (FBOM), orthophosphate (P_PO₄) and periphyton content all increased along the gradient from the natural stream to the urban-dominated catchment. The density of interstitial assemblages corresponded with the conductivity (at P < 0.05) and was higher on the stream in urban-dominated catchments; and the Harpacticoida taxa richness, dominated by the family Canthocamptidae, was also greater here. The Multiple Regression Analysis shows that the rate of deforestation had had the most significant effect on the density of hyporheos. Among of crustacean fauna the representatives of epigean harpacticoids from (of) family Canthocamptidae, dominated.     

High affinity small protein inhibitors of human chymotrypsin C (CTRC) selected by phage display reveal unusual preference for P4' acidic residues

Human chymotrypsin C (CTRC) is a pancreatic protease that participates in the regulation of intestinal digestive enzyme activity. Other chymotrypsins and elastases are inactive on the regulatory sites cleaved by CTRC, suggesting that CTRC recognizes unique sequence patterns. To characterize the molecular determinants underlying CTRC specificity, we selected high affinity substrate-like small protein inhibitors against CTRC from a phage library displaying variants of SGPI-2, a natural chymotrypsin inhibitor from Schistocerca gregaria. On the basis of the sequence pattern selected, we designed eight inhibitor variants in which amino acid residues in the reactive loop at P1 (Met or Leu), P2' (Leu or Asp), and P4' (Glu, Asp, or Ala) were varied. Binding experiments with CTRC revealed that (i) inhibitors with Leu at P1 bind 10-fold stronger than those with P1 Met; (ii) Asp at P2' (versus Leu) decreases affinity but increases selectivity, and (iii) Glu or Asp at P4' (versus Ala) increase affinity 10-fold. The highest affinity SGPI-2 variant (K(D) 20 pm) bound to CTRC 575-fold tighter than the parent molecule. The most selective inhibitor variant exhibited a K(D) of 110 pm and a selectivity ranging from 225- to 112,664-fold against other human chymotrypsins and elastases. Homology modeling and mutagenesis identified a cluster of basic amino acid residues (Lys(51), Arg(56), and Arg(80)) on the surface of human CTRC that interact with the P4' acidic residue of the inhibitor. The acidic preference of CTRC at P4' is unique among pancreatic proteases and might contribute to the high specificity of CTRC-mediated digestive enzyme regulation.     

New behavioural trait adopted or rejected by observing heterospecific tutor fitness

Animals can acquire behaviours from others, including heterospecifics, but should be discriminating in when and whom to copy. Successful individuals should be preferred as tutors, while adopting traits of poorly performing individuals should be actively avoided. Thus far it is unknown if such adaptive strategies are involved when individuals copy other species. Furthermore, rejection of traits based on tutor characteristics (negative bias) has not been shown in any non-human animal. Here we test whether a choice between two new, neutral behavioural alternatives-breeding-sites with alternative geometric symbols-is affected by observing the choice and fitness of a heterospecific tutor. A field experiment replicated in four different areas shows that the proportion of pied flycatcher females matching the choice of the tit tutor consistently increased with increasing number of offspring in the tit nest, to the extent of nearly complete prevalence in one of the areas when tit fitness was highest. Notably, all four replicates demonstrate rejection of the behaviour of lowest-fitness tutors. The results demonstrate both acquisition and avoidance of heterospecific behavioural traits, based on the perceived (lack of) tutor fitness. This has potential implications for understanding the origin, diversity and local adaptations of behavioural traits, and niche overlap/partitioning and species co-occurrence.     

Reproductive biology of the greyfin croaker <Emphasis Type="Italic">Pennahia anea</Emphasis> in the northern South China Sea

The greyfin croaker Pennahia anea is one of the most common croakers currently on retail sale in Hong Kong, but there are no regional studies on its biology or fishery. The reproductive biology of the species, based on 464 individuals obtained from local wet markets, was studied over 16 months (January 2008–April 2009) using gonadosomatic index (GSI) and gonad histology. Sizes used in this study ranged from 8.0 to 19.0 cm in standard length (SL). Both the larger and smaller size classes were missing from samples, implying that they are infrequently caught in the fishery. Based on GSI data, the approximate minimum sizes for male and female maturation were 12 cm SL. The size at 50% maturity for females was 14.3 cm SL, while all males in the samples were mature. Both GSI and gonad histology suggest that spawning activity occurred from March–April to June, with a peak in May. Since large croakers are declining in the local and regional fisheries, small species such as P. anea are becoming important, although they are mostly taken as bycatch. In view of unmanaged fishing pressure, and given the decline in large croakers and sizes of P. anea presently caught, proper management of the species is suggested.     

Behavioral Trait of Morningness-Eveningness in Association with Articular and Spinal Diseases in a Population

Earlier studies have revealed that the more the preference to schedule daily activities towards the evening hours is, the higher the odds for a range of health hazards are. Therefore, we wanted to analyze, whether the behavioral trait of morningness-eveningness is associated with articular and spinal diseases or those with musculoskeletal disorders. Participants (n = 6089), as part of the National FINRISK 2007 Study, were derived from the general population, aged 25 to 74 years, living in Finland. Chronotype was assessed based on six items from the original Horne-Östberg Morningness-Eveningness Questionnaire. Information about risk factors and the diagnoses of articular and spinal diseases were based on the self-reported information. Our results suggest that Evening-types have higher odds for articular and spinal diseases as compared with Morning-types, and this risk is heightened especially regarding spinal disease and backache (odds ratios of 1.8 to 2.1, and 1.6 to 1.8, respectively) and remains significant after controlling for the sex, age, education, civil status, physical activity, alcohol use, and smoking, and additionally for the body-mass index, insufficient sleep, or depressive symptoms.     

Blackfly assemblages (Diptera,Simuliidae) of the Carpathian river: habitat characteristics,longitudinal zonation and eutrophication

Investigations were carried out in 2003–04 within a project on trend biomonitoring of macrozoobenthos in the Hron River system. They were focused on blackfly assemblages of the Hron River (Slovakia), using the distribution patterns of blackflies (18 species) from 14 sites, representing a fluent transition from epirithral to epipotamal. Two main “sister” groups were distinguished using TWINSPAN analysis. Prosimulium rufipes is an indicator species within the first group. This group typically occurs in the zone representing a part of the river upstream and its tributaries. Simulium lineatum is an indicator species within the second group that occurs in the zone representing the middle and lower part of the river. The Upstream–Downstream gradient represents, in fact, the ecological position (EP) of the studied localities of the Hron River along the River Continuum Concept. The distribution fitting analysis divides the distribution amplitude data of blackfly species into three sets of nonoverlaping intervals: (1) 0.00–0.19 stenotopic (P. rufipes in the upper course of the river, Simulium erythrocephalum in the lower course of the river), (2) 0.20–0.39 mesotopic (Simulium argyreatum, S. equinum—hyporhithral) and (3) 0.40–0.50 eurytopic (Simulium reptans, S. variegatum). According to CCA the most important variables correlated with the first axis, and were linked to the nitrate and maximal water temperature which gradually increase from the upper stretch of the river. Handling editor: K. Martens