Localization of P42 and F1-ATPase α-Subunit Homolog of the Gliding Machinery in Mycoplasma mobile Revealed by Newly Developed Gene Manipulation and Fluorescent Protein Tagging

Mycoplasma mobile has a unique mechanism that enables it to glide on solid surfaces faster than any other gliding mycoplasma. To elucidate the gliding mechanism, we developed a transformation system for M. mobile based on a transposon derived from Tn4001. Modification of the electroporation conditions, outgrowth time, and colony formation from the standard method for Mycoplasma species enabled successful transformation. A fluorescent-protein tagging technique was developed using the enhanced yellow fluorescent protein (EYFP) and applied to two proteins that have been suggested to be involved in the gliding mechanism: P42 (MMOB1050), which is transcribed as continuous mRNA with other proteins essential for gliding, and a homolog of the F₁-ATPase α-subunit (MMOB1660). Analysis of the amino acid sequence of P42 by PSI-BLAST suggested that P42 evolved from a common ancestor with FtsZ, the bacterial tubulin homologue. The roles of P42 and the F₁-ATPase subunit homolog are discussed as part of our proposed gliding mechanism.     

Relationship between boron content and antioxidant compounds in Citrus leaves taken from fields with different water source

Boron contamination in the agricultural lands is an important problem for Western Turkey, which has rich boron deposits. This study was carried out in Nazilli regions upon orange (Citrus sinensis L. Osbeck) plants irrigated with relatively high boron laden channel waters (LCI) and with well waters (LWI) which contain lower amounts of boron. The leaves of the plants irrigated with channel water were found to contain twice the amount of boron compared with those irrigated with well waters. Boron content of leaves in both groups were approximately ten times the boron content in the soil on which they are grown. In the leaves of the plants irrigated with channel waters there were approximately 50% chlorophyll loss and higher chlorophyll a/b and caretonoid/chlorophyll ratios. In the excessive boron containing leaves was found higher soluble protein and carbohydrate contents, but lower determined free proline value. In plants that irrigated with high boron laden channel water significantly lower -tocopherol content and two fold higher ascorbate concentration were determined. The lower activities of catalase and glutathione reductase enzymes and higher total superoxide dismutase activity were measured in high boron content leaves. The retardation of growth due to boron toxicity can be attributed to the chlorophyll loss and inhibition of the carbohydratemetabolism. Boron at toxic level may cause the cell membrane lipids to be damaged by the free radicals by decreasing the -tocopherol levels. The increase in the ascorbate concentration may have a vital role in the protection of the inner cell structures against the boron toxicity.     

c-Myc localization within the nucleus: evidence for association with the PML nuclear body

Definitive localization of c-Myc within the nucleus is important to fully understand the regulation and function of this oncoprotein. Studies of c-Myc distribution, however, have produced conflicting results. To overcome technical challenges inherent in c-Myc cytology, we use here three methods to visualize c-Myc and in addition examine the impact of proteasome inhibition. EYFP or HA-tagged Myc was reintroduced by stable transfection into myc null diploid rat fibroblasts, replacing endogenous Myc with tagged Myc expressed at or near normal levels. This tagged Myc is shown to functionally replace the endogenous Myc by restoration of normal cell morphology and growth rate. We were able to confirm key findings using antibodies to the endogenous c-Myc and/or its partner, Max. Contrary to some published reports, by all three methods the c-Myc protein in rat fibroblasts distributes predominantly throughout the nucleus in a dispersed granular pattern, avoiding the nucleolus. Importantly, however, several findings provide evidence for an unanticipated relationship between c-Myc and PML nuclear bodies, which is enhanced under conditions of proteasome inhibition. Evidence of Max concentration within PML bodies is shown both with and without proteasome inhibition, strengthening the relationship between PML bodies and Myc/Max. Some accumulation of Myc and Max in nucleoli upon proteasome inhibition is also observed, although co-localization of ubiquitin was only seen with PML bodies. This work provides a comprehensive study of c-Myc distribution and also presents the first evidence of a relationship between turnover of this oncoprotein and PML nuclear bodies, known to break down in certain cancers.     

Microbiological changes in whiting (Merlangius merlangus Linneaus, 1758) fillets during short‐term cold storage and a traditional ‘pastrami‐like’ treatment

The objective of this study was to test the effects of salt‐dried whiting (Merlangius merlangus) fillet storage when treated with a special paste and stored covered. For this purpose whiting fillets were salt‐dried at 4–6°C for 15 days. A subsequent test series involved a paste mixture prepared from ground fenugreek, cumin seeds, black pepper, red pepper powder and garlic. The fillets were coated with this paste and air‐dried (15–20°C) for 5 days. All microbiological changes during this drying period were noted. The aerobic mesophilic bacterial counts decreased significantly (P < 0.05) from 5.08 ± 0.20 log cfu g^?1 to 3.24 ± 0.06 log cfu g^?1 after 15 days of salt‐drying. After then covering with paste and drying for 5 days (at 15–20°C), the aerobic mesophilic and lactic acid bacteria counts of the fillets increased to 6.05 ± 0.45 and 5.85 ± 0.06 log cfu g^?1, respectively. The pH values of dried whiting fillets changed after 15 days of dry salting (from 6.1 to 6.4), but after coating and drying with the paste, the pH values were 5.6 on day 5. Enterobactericeae were few in number at the start of salt‐drying (about 1.20 ± 0.15 log cfu g^?1), but their number decreased to <1.0 log cfu g^?1 after 15 days of dry‐salt storage. Staphylococcus aureus, Escherichia coli, mould and yeast were not detected at any time of drying. According to the resuts of the microbiological analyses, dried whiting fillet are considered safe for human consumption.     

Effect of absorbent pads containing black seed or rosemary oils on the shelf life of sardine [Sardina pilchardus (Walbaum, 1792)] fillets

The effects of essential oils on the shelf life of sardine (Sardina pilchardus) fillets in cold storage were assessed at 4–6°C. The oils were sprayed on the fillets as well as with the addition of absorbent food pads that also contained essential oils. Sardine fillets were divided into eight test groups. Group A: fillets stored without treatment (control group); Group B: fillets packaged with food pads (without the addition of essential oils); Group C: Rosemary oil sprayed onto food pads (10 ml of 1.5% RO); Group D: Black seed oil sprayed onto the food pads (10 ml of 1.5%BSO); Group E: Rosemary oil sprayed onto both sides of the sardine fillets (10 ml of 1.5%RO); Group F: Black seed oil sprayed onto both sides of sardine fillets (10 ml of 1.5% BO); Group G: Rosemary oil sprayed onto both sides of the sardine fillets (10 ml of 1.5% RO) and on the food pads (+10 ml of 1.5% RO); and Group H: Black seed oil sprayed onto the sardine fillets and the food pads (10 ml of 1.5% BSO onto both sides of fillets +10 ml of 1.5% BSO onto food pads). Tests were carried out at days 0, 3, 5 and 7. When compared to the control group, food pads containing rosemary and black seed oils extended the shelf life of sardine fillets by approximately 2 days at 4–6°C. Group A and B exceeded the limit of consumption on day 3, and Group C and D exceeded this microbiological limit after day 5. RO and BSO both exhibited the same antimicrobial effects on the shelf life of sardine fillets. Groups E, F, G and H prolonged the microbiological threshold by 7 days compared to the control. However, Group G and H had 1–1.5 log lower TVC load than Group E and F. Food pads containing antimicrobial essential oils may be used to extend the shelf life of fresh fish, however, further investigations are needed to determine safety standards.     

Description of oviparous females and alate males of Macrosiphum dzhibladzeae Barjadze, 2010 (Hemiptera: Aphididae) from Georgia

The hitherto unknown oviparous females and alate males of M. dzhibladzeae Barjadze, 2010, living on Euphorbia macroceras Fish. & Mey. and Euphorbia sp. (Euphorbiaceae), are described from resort Bakhmaro (Chokhatauri district, Guria region, Western Georgia). The life cycle of this species is established. Apterous and alate viviparous females and oviparous females of M. dzhibladzeae are compared to the same morphs of morphologically similar M. meixneri Börner, 1950. A key is provided to Euphorbia-feeding Macrosiphum spp. based on males.     

Selenium Levels in First-Degree Relatives of Diabetic Patients

The present study was conducted to evaluate the serum selenium levels in first-degree relatives of diabetic patients (FDR) according to controls. Insulin resistance, serum lipid levels, inflammation markers, and blood pressure were also studied in these patients. Serum levels of selenium in FDR were significantly lower than control group (74.65 ± 5.9 vs 88.7 ± 8.7 μg/dl, p < 0.0001). HsCRP, HOMA-IR, insulin, homocysteine levels were significantly higher in FDR according to the control group (1.32 ± 0.9 vs 0.63 ± 0.4 mg/dL, p < 0.0001; 2.07 ± 0.84 vs 1.51 ± 0.69, p < 0.0001; 9.26 ± 3.8 vs 6.8 ± 2.98 μU/MI, p < 0.0001; 15.7 ± 7.4 vs 11.5 ± 5.1 μmol/L, p < 0.0001, respectively). There was significant correlation between selenium levels and hsCRP (r = − 0.450, p < 0.0001). There was also weak significant correlation also between HOMA-IR and selenium levels (r = −0.227, p = 0.003). There was a correlation between systolic blood pressure and BMI (r = 0.365, p < 0.0001). But there was no correlation between selenium levels and blood pressure or other parameters. HsCRP, HOMA-IR, homocysteine levels in individuals with selenium levels < 80 μg/L (n = 78) was significantly higher than hsCRP HOMA-IR, homocysteine levels in individuals with selenium levels ≥ 80 (n = 91; 1.23 ± 0.98 vs 0.81 ± 0.76 mg/dL, p < 0.003; 1.99 ± 0.88 vs 1.64 ± 0.74, p < 0.005; 15.0 ± 7.6 vs 12.9 ± 5.7 μmol/L, p < 0.049, respectively). Selenium deficiency may contribute to cardiovascular disease risk in FDR.     

Magnetic Tweezers-Based Force Clamp Reveals Mechanically Distinct apCAM Domain Interactions

Cell adhesion molecules of the immunoglobulin superfamily (IgCAMs) play a crucial role in cell-cell interactions during nervous system development and function. The Aplysia CAM (apCAM), an invertebrate IgCAM, shares structural and functional similarities with vertebrate NCAM and therefore has been considered as the Aplysia homolog of NCAM. Despite these similarities, the binding properties of apCAM have not been investigated thus far. Using magnetic tweezers, we applied physiologically relevant, constant forces to apCAM-coated magnetic particles interacting with apCAM-coated model surfaces and characterized the kinetics of bond rupture. The average bond lifetime decreased with increasing external force, as predicted by theoretical considerations. Mathematical simulations suggest that the apCAM homophilic interaction is mediated by two distinct bonds, one involving all five immunoglobulin (Ig)-like domains in an antiparallel alignment and the other involving only two Ig domains. In summary, this study provides biophysical evidence that apCAM undergoes homophilic interactions, and that magnetic tweezers-based, force-clamp measurements provide a rapid and reliable method for characterizing relatively weak CAM interactions.