Navigational features of dove flights in the gravity field of Ukraine

Results of test flights of domestic doves in the flat country of Ukraine characterized by partitioned gravity field (Buge anomalies from -30 to +70 mGal) have been considered. The length of flights from starting point to the place of permanent location was from 15 to 200 km. The routes were tracked trough weakly and strongly divided gravity field. Both local experienced birds and young ones specially bred in outlying gravity fields took part in the flights. GPS sensors were fastened on birds fixing coordinates of flight (ϕ, λ, H) in every 1 sec. Test results demonstrated with other factors (roads, rivers et al.) that gravity anomalies even small ones (±1-2 mGal) produce deviation of dove tracks from the straight line together. It is urgent to continue the experiment which will be corrected taking into account the experience obtained. Inertial-gravitational mechanism of animal navigation has been suggested

Three-dimensional ultrastructural and immunohistochemical study of immature neurons in the subgranular zone of the rat dentate gyrus

The present study is devoted to three dimensional ultrastructural organization of mitotically dividing immature neurons in dentate gyrus using biophysical approaches. In adult vertebrate brain, cell proliferation persists throughout life mainly in dentate gyrus of the hippocampus (DG) and olfactory bulb. Neurogenesis has been demonstrated using tagged thymidine analogues incorporated into the S phase of the cell cycle, but these may also detect repaired DNA in postmitotic neurons. Recent retroviral labelling has shown that neuronal progenitors/neuroblasts divide and produce functional neurons. Providing ultrastructural evidence of mitotically active cells has proven problematical, not only because of technical issues of identifying dividing cells at electron microscope level, but also because it is difficult to demonstrate unequivocally that neurons identified in the electron microscope are really post mitotic. However by characterising post mitotic cells labelled with BrdU and doublecortin and comparing these with post mitotic cells reconstructed in 3 dimensions from ultrathin serial sections, we have been able to illustrate individual mitotic elements and phases of cells within the GC layer of adult rat dentate gyrus. Here we show dividing cells in metaphase within clusters of immature GCs in subgranular zone (SGZ). These reconstructions provide ultrastructural confirmation that cells expressing doublecortin (DCX), a microtubule associated protein expressed in migrating neurons, localize as clusters in the subgranular zone (SGZ) of dentate gyrus (DG) in the hippocampus during all animal life. Such DG cells with clear synaptic specializations, somatic spines and basal dendrites are exclusive to immature GC that appear to reenter the cell cycle, suggesting the possibility that newly generated neurons within the DG might arise not only from precursors, but also from clusters of immature GC

Deletion of the <i>dps</i> gene affects <i>rpoA</i> and <i>rpoB</i> expression.

<p><b>A:</b> Profiles of the Dps binding sites obtained in two experiments (indicated) for the genomic region with three operons of ribosomal genes (running window of nine 35 bp bins). Genes are represented by blue horizontal arrows; magenta lines show ribosomal operons. Vertical arrows mark locations of inverted repeats (if longer than 7 bp). <b>B:</b> Band shift assays performed for indicated genomic loci. The regulatory region of the <i>dps</i> gene was used as a positive control for all band shift assays in this study. Fragment from the <i>lacZ</i> coding sequence was used as a reference gene for qRT-PCR experiments. Positioning of primers for amplification (<b>F</b> and <b>R</b>) is indicated in panel <b>A</b> of this figure, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.g006" target="_blank">Fig 6A</a> (for the <i>dps</i> regulatory region) and in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.s003" target="_blank">S3 Fig</a> (for <i>rpoA</i> and <i>lacZ</i>). <b>C:</b> Changes in the expression efficiency of selected genes in response to <i>dps</i> deletion. Primers used for reverse transcription and consecutive PCR are designated as RT and PCR, respectively, here and all other figures. Expression levels were estimated based on 3 and 5 biological samples (3–18 technical repeats in each) for <i>rpoA</i> and <i>rpoD</i>, respectively. Error bars show an average deviation. Statistical significance was assessed using Student’s t-test.</p

Large-scale profiles of the Dps targets correlate with the landscape of direct and inverted repeats and the pattern of Fis binding sites.

<p><b>A:</b> Distribution of the Dps contact regions along the <i>E</i>. <i>coli</i> MG1655 genome identified by CLC GW in two experiments (the default settings). The areas covered by Dps are combined in 100,000 bp bins and plotted as percentage to the total length of all sites occupied by Dps. <b>B</b>: The same for the contact sites of Fis [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref049" target="_blank">49</a>], IHF [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref051" target="_blank">51</a>], H-NS [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref049" target="_blank">49</a>] and RNAP [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref050" target="_blank">50</a>] from the cells grown in conditions similar to those used in our experiments. The plot for Dps shows the distribution of the sites from the combined set (<b>CS</b>) (Page 3, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.s009" target="_blank">S3 Table</a>). <b>C:</b> The same for direct (5–24 bp separated by 1–15 bp) and inverted (5–18 bp separated by 3–20 bp) repeats collected from the genome of <i>E</i>. <i>coli</i> MG1655 using Unipro UGENE [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref053" target="_blank">53</a>].</p

Dps shares its binding sites with other proteins of bacterial nucleoid and has affinity to REP-elements and <i>promoter islands</i>.

<p>Intersection of Dps targets (<b>A</b>) and sites unbound by Dps (<b>B</b>) with structural and functional elements of bacterial genome was estimated as described above for repeated sequences and plotted as fold ratio to the expected values. Bent black arrows on the bottom schematically show areas occupied by CS or UR. Gray rectangles and numerals inside indicate the expected number of common base pairs if compared modules are independently distributed along the genome. Gray and colored bent arrows show registered overlap calculated in 1 bp resolution. Numerals in parenthesis indicate the size of compared sets. Genomic locations of REP elements were taken from KEGG DataBase (<a href="http://www.genome.jp/kegg/" target="_blank">http://www.genome.jp/kegg/</a>, [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref063" target="_blank">63</a>]), and fold ratios obtained for 302 REP-sequences containing 1–3 REP-modules (14–100 bp) were plotted. Analyzed ChIP-chip and ChIP-seq data sets were obtained from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref046" target="_blank">46</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182800#pone.0182800.ref051" target="_blank">51</a>] for cells grown in LB medium (LB), M9 medium with fructose (M9) or MOPS minimal medium with glucose (GMM), harvested at early (EE), middle (ME) or late (LE) exponential phase or upon transition to the steady growth (TS).</p