Evaluation of protein extraction methods for Vitis vinifera leaf and root proteome analysis by two-dimensional electrophoresis

An efficient protein extraction method is crucial to ensure successful separation by two-dimensional electrophoresis(2-DE)for recalcitrant plant species, in particular for grapevine(Vitis vinifera L.). Trichloroacetic acid-acetone(TCA-acetone)and phenol extraction methods were evaluated for proteome analysis of leaves and roots from the Tunisian cultivar 'Razegui'. The phenol-based protocol proved to give a higher protein yield,a greater spot resolution, and a minimal streaking on 2-DE gels for both leaf and root tissues compared with the TCA-based protocol. Furthermore, the highest numbers of detected proteins on 2-DE gels were observed using the phenol extraction from leaves and roots as compared with TCA-acetone extraction.     

Genome wide analysis in a family with sensorineural hearing loss,autism and mental retardation

Hearing loss is a common congenital anomaly with an incidence of 1 in 1000 live births. It has been described together with several other clinical features as fortuitous association or commune genetic syndrome. In this study, we investigated a consanguineous Tunisian family with moderate to profound congenital hearing loss, mental retardation and autistic behaviors. We performed a genome wide microarray analysis study using approximately 300,000 SNPs in a common set of 7 invidious of this family. We identified regions of suggestive linkage with hearing loss on chromosomes 6p12 and 7q34. In addition, we identified a deletion on chromosome 8p in the two autistic individuals. This report presents an illustration of how consanguinity could increase familial clustering of multiple hereditary diseases within the same family. The application of next generation sequencing for this family seems to be a good strategy for further analysis leading to the identification of candidate genes.     

A new Lactobacillus plantarum strain, TN8, from the gastro intestinal tract of poultry induces high cytokine production

This study aimed to determine the probiotic potential of 100 strains of Lactic Acid Bacteria (LAB) isolated from different intestinal segments of indigenous poultry in Tunisia. The strains were submitted to a battery of standard tests and criteria commonly used for determining their probiotic properties and attributes. The findings revealed that 19 of the isolates exhibited antimicrobial activity against 4 pathogenic bacteria, and that 4 (TN1, TN8, TN7, and TN13) showed good resistance to pH 3 and 5% bovine bile. Three isolates, namely TN1, TN8, and TN13, showed sensitivity to several antibiotics and were, therefore, selected for further enzymatic activity assays. Two isolates, namely TN1 and TN8, showed high efficacy of adhesion to chicken enterocytes. The cytokines released after stimulation by the two isolates showed high anti-inflammatory profiles, with an increased rate of Interleukin-10 (IL-10) production for the TN8 strain. Showing the highest performance, TN8 was submitted to 16S rRNA gene sequencing, which revealed that the strain was of the species Lactobacillus plantarum. Overall, the findings indicate that the Lactobacilli from poultry intestine has a number of promising properties that make it candidate for application as a probiotic additive in poultry industry.     

Lipid peroxidation,antioxidant activities and stress protein (HSP72/73, GRP94) expression in kidney and liver of rats under lithium treatment

The present work was aimed at studying the effects of a subchronic lithium treatment on rat liver and kidneys, paying attention to the relationship between lithium toxicity, oxidative stress, and stress protein expression. Male rats were submitted to lithium treatment by adding 2 g of lithium carbonate/kg of food for different durations up to 1 month. This treatment led to serum concentrations ranging from 0.5 mM (day 7) to 1.34 mM (day 28) and renal insufficiency highlighted by an increase of blood creatinine and urea levels and a decrease of urea excretion. Lithium treatment was found to trigger an oxidative stress both in kidney and liver, leading to an increase of lipid peroxidation level (TBARS) and of superoxide dismutase and catalase activities. Conversely, glutathione peroxidase activity was reduced. Constitutive HSP73 (heat shock protein 73) expression was not modified by lithium treatment, whereas inducible HSP72 was down-regulated in kidney. GRP94 (glucose regulated protein 94) appeared as two isoforms of 92 and 98 kDa: the 98-kDa protein being overexpressed in kidney by lithium treatment whereas 92-kDa protein was underexpressed both in kidney and liver.     

Somatic embryogenesis and organogenesis from mature caryopses of North African barley accession “Kerkena” (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.)

The regeneration ability of a Tunisian barley accession originated from Kerkena islands was monitored through somatic embryogenesis and organogenesis. To prevent or to reduce normal germination, longitudinally bisected as well as base-wounded mature caryopses were cultured on a modified Chée and Pool-based medium (CP) enriched with different phytohormonal combinations. The greatest embryogenesis response was obtained when base-wounded caryopses were cultured on CP enriched with 2 mg/l chlorophenoxyacetic acid + 2.5 mg/l kinetin (76.85%). The same combination coupled to longitudinally bisected caryopses led to the embryogenic induction at the hypocotyl base of the germinated caryopses (61.9%). Embryogenic calluses differentiated into globular, heart-shaped, torpedo, and fully differentiated stages of somatic embryos on hormone-free Murashige and Skoog-based medium. Rooted plantlets were successfully transferred to soil and grown to maturity in the greenhouse and produced fertile seeds within 3 mo. On the other hand, organogenesis was achieved on CP enriched with 2 mg/l 2,4-dichlorophenoxyacetic acid + 2.5 mg/l kinetin. Histological aspects and scanning electron microscopy of both regeneration methods confirmed further the embryogenic and organogenic nature of the established processes. This efficient plant regeneration system provides a foundation for generating transgenic plants and germplasm preservation of “Kerkena” barley accession.