Similarities and distinctions in Y chromosome gene pool of Western Slavs

Analysis of Y chromosome Y‐STRs has proven to be a useful tool in the field of population genetics, especially in the case of closely related populations. We collected DNA samples from 169 males of Czech origin, 80 males of Slovakian origin, and 142 males dwelling Northern Poland. We performed Y‐STR analysis of 12 loci in the samples collected (PowerPlex Y system from Promega) and compared the Y chromosome haplotype frequencies between the populations investigated. Also, we used Y‐STR data available from the literature for comparison purposes. We observed significant differences between Y chromosome pools of Czechs and Slovaks compared to other Slavic and European populations. At the same time we were able to point to a specific group of Y‐STR haplotypes belonging to an R1a haplogroup that seems to be shared by Slavic populations dwelling in Central Europe. The observed Y chromosome diversity may be explained by taking into consideration archeological and historical data regarding early Slav migrations. Am J Phys Anthropol 142:540–548, 2010. © 2010 Wiley‐Liss, Inc.     

Knowledge and Perceptions of,and Attitudes to,Bats by People Living around Arabuko-Sokoke Forest,Malindi-Kenya

Bat populations continue to decline worldwide because of myriad human activities. To enhance bat conservation, human behavior needs to change. Such change can occur, in part, through an understanding of what motivates human actions toward bats. We used a Bat Attitude Questionnaire (BAQ) to investigate attitudes toward bats in people (n = 394) living around Arabuko-Sokoke Forest (ASF), Kenya. Belief in myths seemed to prevail among those surveyed and that these myths were significantly associated with low tolerance of bats (ordinal regression, p < 0.05). Older and more educated people reported more positive attitudes toward bats than others. Multiple linear regression revealed that females showed more negative attitudes toward, and more belief in, myths about bats than males (both p < 0.01). Ordinal regression showed that hostile behavior toward bats was more common among males (p < 0.001). Nearly one-third of the respondents reported actively killing bats or destroying bat roosts. A similar proportion did not see any benefits of bats to humans, while the majority of respondents associated bats with the destruction of farmers’ fruits. To address prevailing negative attitudes about bats, we recommend conducting evening school-based bat study tours, specifically targeting youths in schools around the forest, to examine whether physical contacts with bats would help positively influence human attitudes toward bats. Additionally, since mango (Mangifera indica) farming is an important source of income to people around ASF, an assessment of the quantity of mangoes destroyed by bats would be important to determine whether there is a need for controlling bat access to crops through appropriate schemes.     

Is plasticity in mating preferences adapted to perceived exposure to pathogens?

Humans are unique among primates due to a lack of typical thermally insulating fur. The ectoparasite avoidance mediated by the mate choice hypothesis suggests that the loss of body hair reduces the risk of infection by ectoparasites and that the movement toward nudity may have been enforced by parasite-mediated sexual selection. In this study, we investigated two possible predictions of this hypothesis: (1) that preferences for hairless bodies increase with exposure to environmental pathogens and (2) that disgust sensitivity to the pathogens’ threat predicts the degree to which a woman will prefer hairless bodies. Using an experiment comparing the preferences of 88 women for shaved vs. hairy pictured versions of 20 male torsos, we found that exposure to the visual cues of pathogens does not predict preferences for a male chest nor does the individual disgust sensitivity to disease-related invertebrates. Overall, the results suggest that female perception of male trunk hair is not associated with a risk of contamination, which questions the salience of the ectoparasite avoidance hypothesis in explaining the loss of body hair in humans.     

piRNAs, transposon silencing, and germline genome integrity

Integrity of the germline genome is essential for the production of viable gametes and successful reproduction. In mammals, the generation of gametes involves extensive epigenetic changes (DNA methylation and histone modification) in conjunction with changes in chromosome structure to ensure flawless progression through meiotic recombination and packaging of the genome into mature gametes. Although epigenetic reprogramming is essential for mammalian reproduction, reprogramming also provides a permissive window for exploitation by transposable elements (TEs), autonomously replicating endogenous elements. Expression and propagation of TEs during the reprogramming period can result in insertional mutagenesis that compromises genome integrity leading to reproductive problems and sporadic inherited diseases in offspring. Recent work has identified the germ cell associated PIWI Interacting RNA (piRNA) pathway in conjunction with the DNA methylation and histone modification machinery in silencing TEs. In this review we will highlight these recent advances in piRNA mediated regulation of TEs in the mouse germline, as well as mention the repercussions of failure to properly regulate TEs.     

Impact of mitochondrial beta-oxidation in fatty acid-mediated inhibition of glioma cell proliferation

Tetradecylthioacetic acid (TTA), which cannot be beta-oxidized, exerts growth-limiting properties in glioma cells. In order to investigate the importance of modulated lipid metabolism and alterations in mitochondrial properties in this cell death process, we incubated glioma cells both with TTA and the oxidizable fatty acid palmitic acid (PA), in the presence of L-carnitine and the carnitine palmitoyltransferase inhibitors etomoxir and aminocarnitine. L-carnitine partly abolished the PA-mediated growth reduction of glioma cells, whereas etomoxir and aminocarnitine enhanced the antiproliferative effect of PA. The production of acid-soluble products increased and the incorporation of PA into glycerolipids decreased after L-carnitine supplementation. L-carnitine was found to enhance the antiproliferative effect of TTA, but did not affect the incorporation of TTA into glycerolipids, or ceramide. PDMP, sphingosine 1-phosphate, desipramine, fumonisin B(1), and L-cycloserine were able not to rescue the glioma cells from PA and TTA-induced growth inhibition, suggesting that increased ceramide production is not important in the growth reduction. TTA-mediated growth inhibition was accompanied with an increased uptake of PA and increased incorporation of PA into triacylglycerol (TG). Our data suggest that mitochondrial functions are involved in fatty acid-mediated growth inhibition. Whether there is a causal relationship between TG accumulation and the apoptotic process remains to be determined.     

Effects of non-ionic surfactants N-alkyl-N,N-dimethylamine-N-oxides on the structure of a phospholipid bilayer: small-angle X-ray diffraction study

Effects of non-ionic surfactants N-alkyl-N,N-dimethylamine-N-oxides (C(n)NO, n is the number of alkyl carbons) on the structure of egg yolk phosphatidylcholine (EYPC) bilayers in the lamellar fluid phase was studied by small-angle X-ray diffraction as a function of H(2)O:EYPC and C(n)NO:EYPC molar ratios. The bilayer thickness d(L) and the lipid surface area at the bilayer-aqueous interface S(L) were calculated from the repeat period, d of the lamellar phase, based on the model that water and EYPC + CnNO molecules form separated layers and that their molecular volumes are additive. In the studied range of m=CnNO:EYPC molar ratios up to 1:1, d(L) and S(L) change linearly. The slopes Delta L = delta dL/ delta m and Delta S= delta S L / delta m are equal to -0.876 +/- 0.027 nm and 0.347 +/- 0.006 nm2 for C(6)NO, -1.025+/-0.060 nm and 0.433+/-0.025 nm(2) for C(8)NO, -0.836+/-0.046 nm and 0.405+/-0.018 nm(2) for C(10)NO, -0.604+/-0.015 nm and 0.375+/-0.007 nm(2) for C(12)NO, -0.279+/-0.031 nm and 0.318+/-0.005 nm(2) for C(14)NO, -0.0865+/-0.070 nm and 0.2963 +/-0.014 nm(2) for C(16)NO, and -0.040+/-0.022 nm and 0.297+/- 0.002 nm(2) for C(18)NO, respectively, at full bilayer hydration. The peak-peak distance in the bilayer electron density profile, which relates to the P-P distance d(PP), obtained from the first four diffraction peaks by the Fourier transform also depends linearly on m, and the slope Delta PP = delta dPP/delta m is -0.528+/-0.065 nm for C(6)NO, -0.680+/-0.018 nm for C(8)NO, -0.573+/-0.021 nm for C(10)NO, -0.369+/-0.075 nm for C(12)NO, -0.190+/-0.015 for C(14)NO, -0.088+/-0.016 nm for C(16)NO and -0.094+/-0.016 nm for C(18)NO. The effects of C(n)NO on Delta(L), Delta(S) and Delta(PP) are the results of C(n)NO insertion into EYPC bilayers and depend on the hydrophobic mismatch between C(n)NO and EYPC hydrocarbon chains and on the lateral interactions of C(n)NO and EYPC in the bilayer.     

Ion selectivity of a poly(3-pentylmethoxythiophene) LB-layer modified carbon-fiber microelectrode as a consequence of the second order filtering in voltcoulometry

Ion selective properties of poly(3-pentylmethoxythiophene) Langmuir-Blodgett film modified carbon-fiber microelectrode are described. The study of the electrode behavior indicates that important features occur if two electrochemical methods, one of them being kinetics sensitive, are used. While in case of the typical steady-state voltammetry the electrode remains sensitive to both the cations and anions, the kinetics-sensitive properties of voltcoulometry based on the second-order filtering scheme disable the observation of anions. As a model system a mixture of copper and dopamine ions is used.     

In vitro identification of mitochondrial oxidative stress production by time-resolved fluorescence imaging of glioma cells

Oxidative phosphorylation and glycolysis are important features, by which cells could bypass oxidative stress. The level of oxidative stress, and the ability of cells to promote oxidative phosphorylation or glycolysis, significantly determined proliferation or cell demise. In the present work, we have employed selective mitochondrial probe MitoTracker? Orange CMTM/Ros (MTO) to estimate the level of oxidative stress in cancer cells at different stressed conditions. MTO is partially sensitive to decrease of mitochondrial membrane potential and to reactive oxygen species (ROS) generated in mitochondria. We have demonstrated, that fluorescence lifetime of MTO is much more sensitive to oxidative stress than intensity-based approaches. This method was validated in different cancer cell lines. Our approach revealed, at relatively low ROS levels, that Gö 6976, a protein kinase C (PKC) α inhibitor, and rottlerin, an indirect PKCδ inhibitor, increased mitochondrial ROS level in glioma cell. Their involvement in oxidative phosphorylation and apoptosis was investigated with oxygen consumption rate estimation, western blot and flow-cytometric analysis. Our study brings new insight to identify feeble differences in ROS production in living cells.     

Some ecophysiological features in leaves of plants in an oak-hornbeam forest

Six different leaf indexes, indicating the anatomical and ecophysiological features in leaves, were used for characterizing the three principal layers (tree, shrub and herb) of an oak-hornbeam forest in southwest Slovakia, Czechoslovakia. The most pronounced differences in the leaf indexes followed were found between those at the active surface of the forest canopy (sun leaves of tall trees) and those in the herb layer. Differences exist between individual layers as well as between species within each layer. They should be taken into consideration in ecological and ecophysio-logical studies and in modelling forest ecosystems.     

Cross-reactive CD4+ T cells against one immunodominant tumor-derived epitope in melanoma patients

TCRs exhibit a high degree of specificity but may also recognize multiple and distinct peptide-MHC complexes, illustrating the so-called cross-reactivity of TCR-peptide-MHC recognition. In this study, we report the first evidence of CD4(+) T cells recognizing the same tumor peptide-epitope from NY-ESO-1, in the context of multiple HLA-DR and HLA-DP molecules. These cross-reactive CD4(+) T cells recognized not only autologous but also allogenic dendritic cells previously loaded with the relevant protein (i.e., the normally processed and presented epitope). Using clonotypic real-time RT-PCR, we have detected low frequencies of CD4(+) T cells expressing one cross-reactive TCR from circulating CD4(+) T cells of patients with stage IV melanoma either spontaneously or after immunization but not in normal donors. The maintenance of cross-reactive tumor Ag-specific CD4(+) T cells in PBLs of cancer patients required the presence of tumor Ag/epitope in the context of the MHC molecule used to prime the Ag-specific CD4(+) T cells. Our findings have significant implications for the optimization of TCR gene transfer immunotherapies widely applicable to cancer patients.