Rhythmic cyclic AMP changes in Chlamydomonas cells synchronized by temperature and light cycles in chemostat culture

Division in chemostat cultures of Chlamydomonas reinhardi was synchronized by daily cycles of both temperature and light. In response to 8 h cool (20 degrees C) - dim light/16 h warm (28 degrees C) - bright light cycles and continuous dilution that removed half the cells daily, the cells replicated nuclear DNA late in the warm-bright phase; released an average of two daughter zoospores early in the warm-bright phase of the next cycle. In these synchronized green algal cultures all ATP and most cAMP were intracellular; most cGMP (approximately 91%) was extracellular. Early in the warm-bright phase ATP doubled after which cAMP level fell 25%. During DNA replication cAMP level doubled, rising to a modest peak reached as replication ended.     

The characterization of aluminium — alanine complex

The potentiometric titration curves and computer modelling studies indicated that aluminium complexes with alanine at-C00^– moiety and also altered the proton affinity at⁺NH₃ and-CH₃ moiety.²⁷Al NMR spectra broadening also confirmed the interaction.     

Evaluation of the alleviative role of Chlorella vulgaris and Spirulina platensis extract against ovarian dysfunctions induced by monosodium glutamate in mice

Microalgae provide a wealthy natural resource of bioactive compounds, which have many biological activities. Monosodium glutamate is a food additive that acts either as food preservatives or as tastiness enhancer. It was confirmed that monosodium glutamate poses a serious responsibility in the pathogenesis of anovulatory infertility. Therefore, the idea of this research was directed to reveal efficiency of Chlorella vulgaris and Spirulina platensis extracts against the ovarian dysfunction resulted due to monosodium glutamate consumption. Adult female albino mice were gavages orally monosodium glutamate alone or with either Chlorella vulgaris or Spirulina platensis aqueous extracts for 28?days. Female mice were subjected to superovulation to study the oocytes nuclear maturation stages. Histological and quantitative investigation was carried on ovaries. Biochemical assessment to measure the sex hormones level and ovarian enzymatic antioxidants was done. In addition, ovarian antioxidant mRNA genes were determined using quantitative PCR and Glyceraldehyde-3-phosphate dehydrogenase was used as an internal control. The result revealed that monosodium glutamate reduced the oocytes quality and maturation rate, while, both algae improve the oocyte quality and maturation rate than in monosodium glutamate group. Chlorella vulgaris and Spirulina platensis improved the monosodium glutamate ovarian tissue histological alteration, sex hormones content and raised the ovarian enzymatic antioxidants level. In addition, monosodium glutamate markedly diminished the Glutathione peroxidase, superoxide dismutase and catalase mRNA expressions, However, Chlorella vulgaris or Spirulina platensis upregulated the expression of genes close to control. In conclusion, Chlorella vulgaris and Spirulina platensis showed potential alleviative role against the monosodium glutamate ovarian dysfunction.     

Mitochondrial DNA variation reveals maternal origins and demographic dynamics of Ethiopian indigenous goats

The Horn of Africa forms one of the two main historical entry points of domestics into the continent and Ethiopia is particularly important in this regard. Through the analysis of mitochondrial DNA (mtDNA) d‐loop region in 309 individuals from 13 populations, we reveal the maternal genetic variation and demographic dynamics of Ethiopian indigenous goats. A total of 174 variable sites that generated 231 haplotypes were observed. They defined two haplogroups that were present in all the 13 study populations. Reference haplotypes from the six globally defined goat mtDNA haplogroups show the two haplogroups present in Ethiopia to be A and G, the former being the most predominant. Although both haplogroups are characterized by an increase in effective population sizes (N_e) predating domestication, they also have experienced a decline in N_e at different time periods, suggesting different demographic histories. We observed seven haplotypes, six were directly linked to the central haplotypes of the two haplogroups and one was central to haplogroup G. The seven haplotypes were common between Ethiopia, Kenya, Egypt, and Saudi Arabia populations, suggesting common maternal history and the introduction of goats into East Africa via Egypt and the Arabian Peninsula, respectively. While providing new mtDNA data from a historically important region, our results suggest extensive intermixing of goats mediated by human socio‐cultural and economic interactions. These have led to the coexistence of the two haplogroups in different geographic regions in Ethiopia resulting in a large caprine genetic diversity that can be exploited for genetic improvement.     

Large-scale de novo transcriptome analysis reveals specific gene expression and novel simple sequence repeats markers in salinized roots of the euhalophyte <Emphasis Type="Italic">Salicornia europaea</Emphasis>

Glycophytic plants suffer from severe stress and injury when roots are exposed to high salinity in the rhizosphere. In contrast, the euhalophyte Salicornia europaea grows well at 200 mM NaCl and can withstand up to 1000 mM NaCl in the root zone. Analysis of gene expression profiles and the underlying molecular mechanisms responsible for this tolerance have been largely overlooked. Using the Illumina sequencing platform and the short-reads assembly programme Trinity, we generated a total of 40 and 39 million clean reads and further 140,086 and 122,728 unigenes from the 200 mM NaCl and 0 mM NaCl treated tissues of S. europaea roots, respectively. All unigenes in this study were functionally annotated within context of the COG, GO and KEGG pathways. Unigene functional annotation analysis allowed us to identify hundreds of ion transporters related to homeostasis and osmotic adaptation as well as a variety of proteins related to cation, amino acid, lipid and sugar transport. We found significant enrichment in response to stress including the functional categories of “antioxidant activity”, “catalytic activity” and “response to stimuli”. These findings represent for a useful resource for the scientific community working on salt tolerance mechanisms. Conversely, a total of 8639 EST-SSRs from 131,594 unigenes were identified and 4539 non-redundant SSRs primers pairs were developed. These data provide a good foundation for future studies on molecular adaptation mechanisms of euhalophytes roots under saline environments and will likely facilitate the identification of critical salt tolerance traits to be transferred in economically important crops.     

Morpho-anatomical features of the leaves of the mediterranean geophyteUrginea maritima (L) baker (Liliaceae)

The morpho-anatomy and histochemistry of the hysteranthous leaf ofUrginea maritima (L.) Baker and its adaptive strategies to the Mediterranean climate were investigated. The leaf ofU. maritima is 714 μm thick and possesses moderate specific leaf mass (8.564 mg cm^-2) and low tissue density (136.5 mg cm^-3). The epidermal cells are compactly arranged and covered with cuticle. The average density of stomata in lower epidermis is higher than that of the upper one. The mesophyll cells occupy 52.96% of the total volume of the leaf, while the mesophyll intercellular spaces and the air spaces occupy 30.41%. Idioblastic cells containing raphide bundles and different phenotypes of crystalloid inclusions, embedded in polysaccharides, occur in the lower side of the mesophyll. The presence of oil droplets and lipids is evident. Bundle sheath cells are hardly visible with no chloroplasts which are a pronounced C₃ plant character. Plastids containing protein crystalloid inclusions are abundant in the protophloem sieve elements.U. maritima, a deciduous plant, possesses leaves with mesophytic characters, in order to optimize its adaptation to the seasonal fluctuation of environmental conditions of the Mediterranean climate.     

Synthesis and antimicrobial activity of 7 alpha-amino-23,24-bisnor-5 alpha-cholan-22-ol derivatives

A series of 7 alpha-aminobisnorsteroids were synthesized and their in vitro antimicrobial activity was evaluated regarding Gram-positive and Gram-negative bacteria. The stereoselective reductive amination of 7-ketosteroid 3 with NH(4)OAc, in the presence of NaBH(3)CN, afforded a high yield of 7 alpha-aminosteroid 4. The 3,7-diaminobisnorsteroids were obtained by the reductive amination of 4 with NH(4)OT(f), Boc-spermidine, and Boc-spermine. 3 alpha,7 alpha-Diaminobisnorsterol dihydrochloride 15 showed the highest antimicrobial activity against Streptococcus pyogenes 308 A with a MIC value of 1.6 microg/mL. Hemolytic activities of the compounds 13-20 were determined. Compound 13 showed MHC value at 100 microg/mL.