Effect of the cryoprotectant concentration on the in vitro embryo development and cell proliferation of OPS-vitrified porcine blastocysts

Our objective was to study the effect of the concentration of ethylene glycol (EG) and dimethyl sulfoxide (Me₂SO) during vitrification on the development of porcine blastocysts. Vitrification was performed with 0.4 M sucrose and either a Me₂SO and EG mixture (15%, 16% and 17% v/v of each) or EG alone (40% v/v), using superfine open pulled straws. Fresh and vitrified blastocysts were cultured for 48 h and the survival and hatching rates were evaluated. Some vitrified and fresh embryos were processed for Hoechst 33342 staining and proliferation cell nuclear antigen (PCNA) inmunolocalization to determine the proliferation index. The survival rate was similar for fresh and vitrified blastocysts, except for blastocysts vitrified using 15% of cryoprotectants, which displayed lower (P < 0.05) survival than fresh blastocysts. Vitrified and fresh blastocysts had a similar cell proliferation index (range: 75.8 ± 3.2 to 83.7 ± 3). When only hatched blastocysts among groups were compared, the proliferation rate decreased (P < 0.05) after vitrification with 17% of EG–Me₂SO. In conclusion, the concentration of EG–Me₂SO could be decreased to 16% in the vitrification medium with no reduction of the in vitro developmental ability of the blastocysts. In addition, a 40% EG-based medium can be used for vitrification with similar results to those achieved with a medium containing 16% EG–Me₂SO.     

Blueberry prevents bone loss in ovariectomized rat model of postmenopausal osteoporosis

The objective of the present study was to explore the bone protective role of blueberry in an ovariectomized rat model. Thirty 6-month-old female Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx) and divided into three groups: Sham, Ovx (control), Ovx+blueberry (5% blueberry w/w). After 100 days of treatment, rats were euthanized, and blood and tissues were collected. Bone mineral density (BMD) and content of whole body, right tibia, right femur and fourth lumbar vertebra were assessed via dual-energy X-ray absorptiometry. As expected, Ovx resulted in loss of whole-body, tibial, femoral, and 4th lumbar BMD by approximately 6%. Blueberry treatment was able to prevent the loss of whole-body BMD and had an intermediary effect on prevention of tibial and femoral BMD when compared to either Sham or Ovx controls. The bone-protective effects of blueberry may be due to suppression of Ovx-induced increase in bone turnover, as evident by lowered femoral mRNA levels of alkaline phosphatase, collagen type I and tartrate-resistant acid phosphatase to the Sham levels. Similarly, serum osteocalcein levels were also lower in the blueberry group when compared to the Ovx control group, albeit not significantly. In summary, our findings indicate that blueberry can prevent bone loss as seen by the increases in BMD and favorable changes in biomarkers of bone metabolism.     

Characterization of a bacteriocin-producing strain of Enterococcus faecalis from cow’s milk used in the production of Moroccan traditional dairy foods

A bacteriocin-producing lactic acid bacterium (strain 2.5) isolated from cow’s milk used in cheese production from Northern Morocco was selected for its strong anti-listerial activity. The producer strain was identified as Enterococcus faecalis by molecular methods. Strain 2.5 carried the genetic determinants for the two-peptide enterococcal bacteriocin enterocin 1071, and the active bacteriocin was purified to homogeneity by reversed-phase chromatography from culture broths of the producer strain. Strain 2.5 carried two plasmids (of ∼7 and 40 kb). Characterization of strain 2.5 at biosafety level indicated that this strain is non-haemolytic, and lacks the genetic determinants for most of the virulence factors described in enterococci (cylB, cylM, gelE, ace and agg) although it carried the genetic determinants cylA, efaAfs as well as determinants for the sex pheromone peptides cpd, cob, and ccf. Strain 2.5 was resistant to tetracycline, rifampicin, and ciprofloxacin, but it was sensitive to penicillin, ampicillin, vancomycin, and teicoplanin. Results from the present study support the potential role of strain 2.5 as an anti-listerial agent to be tested in traditional fermented foods.     

Solvent-controlled regioselective protection of 5'-O-protected thymidine

This paper describes an efficient procedure for selective 3'-O- or 3-N-protection of 5'-O-tert-butyldimethylsilylthymidine, depending on the use of aprotic polar solvents with low or high dielectric constant, respectively. These syntheses were activated by either ultrasound or microwaves. Several alkyl bromides offer a convenient route to prepare 3'-O- or 3-N-protected and functionalized thymidine derivatives.     

High outcrossing in the annual colonizing species Ambrosia artemisiifolia (Asteraceae)

Background and Aims

Variation in mating patterns may be particularly evident in colonizing species because they commonly experience wide variation in plant density. Here, the role of density for the mating system of Ambrosia artemisiifolia (common ragweed), a wind-pollinated annual colonizing species previously reported as self-compatible, is explored.

Methods

The effect of population density on the proportion of self- and cross-fertilized seeds was examined using allozyme markers and experimental arrays conducted over two seasons in the field. Also the reproductive success of isolated plants located in diverse habitats was measured. The potential occurrence of a physiological mechanism preventing self-fertilization, i.e. self-incompatibility, following controlled self- and cross-pollinations in the glasshouse was examined.

Key Results

Outcrossing rates estimated using allozyme markers were uniformly high, regardless of the spacing between plants. However, when single plants were isolated from congeners they set few seeds. Observations of pollen-tube growth and seed set following controlled pollinations demonstrated that plants of A. artemisiifolia possess a strong self-incompatibility mechanism, contrary to earlier reports and assumptions.

Conclusions

The maintenance of high outcrossing rates in colonizing populations of A. artemisiifolia is likely to be facilitated by the prodigious production of wind-borne pollen, high seed production and extended seed dormancy.Key words: Self-incompatibility, outcrossing rate, density dependence, colonization, wind-pollination, Ambrosia artemisiifolia (ragweed), Asteraceae     

Molecular evidence for a single genetic clone of invasive Arundo donax in the United States

Arundo donax (giant reed) is an aggressive invasive weed of riparian habitats throughout the southern half of the United States from California to Maryland. Native to Asia, the species is believed to have been initially introduced into North America from the Mediterranean region although subsequent introductions were from multiple regions. To provide insight into the potential for biological control of A. donax, genetic variation in plants sampled from a wide geographical area in the United States was analyzed using Sequence Related Amplification Polymorphism (SRAP) and transposable element (TE)-based molecular markers. Invasive individuals from 15 states as well as four populations in southern France were genetically fingerprinted using 10 SRAP and 12 TE-based primer combinations. With the exception of simple mutations detected in four plants, A. donax exhibited a single multilocus DNA fingerprint indicating a single genetic clone. The genetic uniformity of invasive A. donax suggests that classical biological control of the species could be successful. A lack of genetic diversity in the invaded range simplifies identification of native source populations to search for natural enemies that could be used as biocontrol agents.     

Catalysts of Cu(II) and Co(II) ions adsorbed in chitosan used in transesterification of soy bean and babassu oils - a new route for biodiesel syntheses

Catalysts of Cu(II) and Co(II) adsorbed in chitosan was used in transesterification of soy bean and babassu oils. The catalysts were characterized by infrared, atomic absorption and TG, and biodiesels was characterized by infrared, NMR, CG, TG, physic chemistry analysis. The maximum adsorption values found for copper and cobalt cations were 1.584 and 1.260mgg(-1), respectively, in 180min. However, conversion of oils in biodiesel was better when used Co(II) adsorbed in chitosan.     

Effects of Plant Growth Promoting Rhizobacteria (PGPRs) on the Biological Nitrogen Fixation,Nodulation, and Growth of Lupinus albus l. cv. Multolupa

The effects of five plant growth promoting rhizobacteria on the biological nitrogen fixation (BNF), nodulation, and growth promotion of plants of Lupinus albus cv. Multolupa were investigated. The plants were selected for their capacity to use 1‐aminocyclopropane‐1‐carboxylic acid (ACC) as the sole source of nitrogen. Four strains belonged to the genus Pseudomonas (Luc 1, Luc 2, Luc 3, and Luc 4) and one (Luc 5) belonged to the genus Bacillus. Three patterns of inoculation were examined. In the first pattern, PGPRs were inoculated seven days before being inoculated with B. japonicum. In the second pattern, PGPRs and B. japonicum were co‐inoculated, and in the last pattern, PGPRs were inoculated seven days after being inoculated with B. japonicum. The plants were sampled 30 and 45 days after being inoculated with B. japonicum (T1 and T2). In the first pattern of inoculation, Luc 5 significantly increased the biological nitrogen fixation compared to the control at the first sampling time, as did Luc 1 and Luc 4 at the second sampling time. In the second pattern of inoculation, Luc 5 negatively effected the biological nitrogen fixation at both sampling times. In the third pattern of inoculation, all PGPRs caused a decrease in the nitrogen content of the plants compared to the control. The results obtained according to the patterns of inoculation showed that the mechanisms of action of the effects and routes used by Gram‐negative and Gram‐positive strains were clearly different. Competition between PGPRs and B. japonicum, competition for the niches in the rhizoplane, production of auxins, and induction of systemic resistance (ISR) by the production of siderophores or by lipopolysaccharides present in the outer membrane (LPS) are discussed as probable reasons for the effects observed.