A flow cytometric study of chromosomes from rat kangaroo and chinese hamster cells

Summary Chromosomes from rat kangaroo (PTK) and chinese hamster (CHV 79) cells have been prepared for quantitative flow-cytometric analysis. The preparation time was optimized down to 30 (PTK) and 40 min (CHV 79). DAPI was used as a AT-sensitive fluorescent dye to stain for monoparameter DNA measurements. Simultaneous two-parameter DNA-protein analysis was carried out with DAPI and SR 101 (as a general protein fluorochrome) in combination. The karyotype of the PTK cells with 13 (14) chromosomes was separated into 10 DNA peaks. The X-chromosome bearing the nucleolus organizer region generates a distinct peak. The karyotype of the CHV 79 cells with 22 chromosomes was separated into 15 peaks. The DNA profile obtained indicates a geometric grading of the chromosomal amount of AT components in the karyotype of this particular cell line. The simultaneous DNA-protein analysis performed show enough sensitivity of the instrument utilizing high power UV excitation illumination to discriminate the two color emission consisting of blue (DAPI) and red (SR 101) fluorescence. Color overlapping could be completely avoided. Additionally, the quality (number, location, and resolution of peaks) of the DNA distribution was not influenced by the simultaneous application of a second fluorescent stain. Fluorescence activated electronic sorting applied on chromosomal fluorescence distributions providing purified fractions of chromosomes for subsequent biochemical and biological determinations is discussed.     

Die Wirkung von Harnmarken auf Artgenossen beim Haushund

An 11 Versuchstagen wurden die Reaktionen von insgesamt 3 Rüden und 2 Hündinnen auf einem rund 2stündigen Spaziergang in nicht oder wenig bekanntem Gebiet beobachtet. Auf einem ersten Rundgang wurden die spontan abgegebenen Harnmarken eines Versuchstieres mit kleinen Objekten markiert, dann ein zweiter Hund an loser Leine den gleichen Weg (meist in umgekehrter Richtung) entlanggeführt und dessen Reaktionen auf die markierten Stellen registriert. Im ganzen wurden bei den ersten Rundgängen 261 Harnmarken abgesetzt. In 47,1 % der Fälle ging der im zweiten Rundgang vorbeigeführte Hund ohne ersichtlichen Grund an der Harnmarke vorbei. Bei Beachtung der Marken zeigten sich 6 verschiedene Reaktionen: 1. Beschnuppern, 2. Harnen über oder neben die Marke, 3. Scharren mit den Hinterpfoten nach Überharnen, 4. Belecken der Marke, 5. Knurren beim Scharren, 6. Zähneklappern nach Beschnuppern und Belecken. Die Marken von feindlichen Rüden und läufigen Hündinnen werden nach Beschnuppern signifikant häufiger als die eigenen bzw. diejenigen einer nichtläufigen Hündin mit einer weiteren Reaktion beantwortet. Die Marken nichtläufiger Hündinnen und die eigenen Marken ergaben keine unterschiedlichen Reaktionen beim Rüden. Eine Hündin reagiert auf die Marken eines (feindl.) Rüden nicht mehr als ein Rüde auf die eigenen Marken. Die Harnmarken vermitteln dem Hunderüden Informationen darüber, ob sie von einer läufigen Hündin, einem fremden Rüden oder von ihm selbst (bzw. einer nicht-läufigen Hündin) stammen.     

Transgelin Silencing Induces Different Processes in Different Breast Cancer Cell Lines

Transgelin is a protein reported to be a marker of several cancers. However, previous studies have shown both up‐ and down‐regulation of transgelin in tumors when compared with non‐tumor tissues and the mechanisms whereby transgelin may affect the development of cancer remain largely unknown. Transgelin is especially abundant in smooth muscle cells and is associated with actin stress fibers. These contractile structures participate in cell motility, adhesion, and the maintenance of cell morphology. Here, the role of transgelin in breast cancer is focused on. Initially, the effects of transgelin on cell migration of the breast cancer cell lines, BT 549 and PMC 42, is studied. Interestingly, transgelin silencing increased the migration of PMC 42 cells, but decreased the migration of BT 549 cells. To clarify these contradictory results, the changes in protein abundances after transgelin silencing in these two cell lines are analyzed using quantitative proteomics. The results confirmed the role of transgelin in the migration of BT 549 cells and suggest the involvement of transgelin in apoptosis and small molecule biochemistry in PMC 42 cells. The context‐dependent function of transgelin reflects the different molecular backgrounds of these cell lines, which differ in karyotypes, mutation statuses, and proteome profiles.     

Plasmon-Assisted Crystalline Silicon Solar Cell with TiO2 as Anti-Reflective Coating

Plasmonics - The present study focuses on the employment of TiO2 (titanium dioxide) film as an anti-reflective coating (ARC) on thin crystalline silicon (Si)-based solar cells along with the...     

Does operational sex ratio influence relative strength of purging selection in males versus females?

According to theory, sexual selection in males may efficiently purge mutation load of sexual populations, reducing or fully compensating ‘the cost of males’. For this to occur, mutations not only need to be deleterious to both sexes, they also must affect males more than females. A frequently overlooked problem is that relative strength of selection on males versus females may vary between environments, with social conditions being particularly likely to affect selection in males and females differently. Here, we induced mutations in red flour beetles (Tribolium castaneum) and tested their effect in both sexes under three different operational sex ratios (1:2, 1:1 and 2:1). Induced mutations decreased fitness of both males and females, but their effect was not stronger in males. Surprisingly, operational sex ratio did not affect selection against deleterious mutations nor its relative strength in the sexes. Thus, our results show no support for the role of sexual selection in the evolutionary maintenance of sex.     

Enterocin M-Producing Enterococcus faecium CCM 8558 Demonstrating Probiotic Properties in Horses

The effects of non-authochtonous Enterococcus faecium AL41 = CCM 8558, enterocin M-producing and probiotic strain were tested on the microbiota, phagocytic activity, hydrolytic enzymes, biochemical parameters and dry matter in horses based on its previous benefits demonstrated in other animals. E. faecium CCM 8558 sufficiently colonized the digestive tract of horses. At day 14, its counts reached 2.35 ± 0.70 CFU/g (log 10) on average. The identity of CCM 8558 was confirmed by means of PCR after its re-isolation from horse faeces. The inhibition activity of CCM 8558 was demonstrated against Gram-negative aeromonads, counts of which were significantly reduced (P < 0.001). After 14 days application of CCM 8558, a tendency towards increased phagocytic activity (PA) was measured; PA value was 73.13% ± 8.55 on average at day 0/1; at day 14, it was 75.11 ± 8.66%. Cellulolytic, xylanolytic and pectinolytic activity in horse faeces was significantly increased (P < 0.001) at day 14 (after CCM 8558 application) and amylolytic activity as well (P < 0.01) compared to day 0/1. Inulolytic activity increased with mathematical difference 1.378. Dry matter value reached 20.81 ± 2.29% on average at day 0/1; at day 14, it was 20.77 ± 2.59% (P = 0.9725). Biochemical parameters were influenced mostly in the physiological range. These results achieved after application of CCM 8558 in horses are original, giving us further opportunity to continue these studies, to measure additional parameters and to show the benefits of CCM 8558 application in horses.

     

Reconstructing marine plankton food web interactions using DNA metabarcoding

Knowledge of zooplankton in situ diet is critical for accurate assessment of marine ecosystem function and structure, but due to methodological constraints, there is still a limited understanding of ecological networks in marine ecosystems. Here, we used DNA‐metabarcoding to study trophic interactions, with the aim to unveil the natural diet of zooplankton species under temporal variation of food resources. Several target consumers, including copepods and cladocerans, were investigated by sequencing 16S rRNA and 18S rRNA genes to identify prokaryote and eukaryote potential prey present in their guts. During the spring phytoplankton bloom, we found a dominance of diatom and dinoflagellate trophic links to copepods. During the summer period, zooplankton including cladocerans showed a more diverse diet dominated by cyanobacteria and heterotrophic prey. Our study suggests that copepods present trophic plasticity, changing their natural diet over seasons, and adapting their feeding strategies to the available prey spectrum, with some species being more selective. We did not find a large overlap of prey consumed by copepods and cladocerans, based on prey diversity found in their guts, suggesting that they occupy different roles in the trophic web. This study represents the first molecular approach to investigate several zooplankton–prey associations under seasonal variation, and highlights how, unlike other techniques, the diversity coverage is high when using DNA, allowing the possibility to detect a wide range of trophic interactions in plankton communities.