Genetic polymorphism in the manganese superoxide dismutase gene is associated with an increased risk for hepatocellular carcinoma in HCV-infected Moroccan patients

Hepatocellular carcinoma (HCC) ranks among the 10 most common cancers worldwide. The main risk factors for its development are hepatitis B and C virus infections. Hepatitis B and C viruses induce chronic inflammation and oxidative stress that could predispose a cell to mutagenesis and proliferation. Manganese superoxide dismutase (MnSOD) catalyses the detoxification of free radicals, thus playing a crucial role in the protection against damage. A valine (Val) to alanine (Ala) substitution at amino acid 9, mapping within the mitochondrion-targeting sequence of the MnSOD gene, has been associated with an increased cancer risk. The aim of our study was to investigate a possible association of the Val/Ala-MnSOD polymorphism and HCC development in Moroccan patients. Genotypes were determined by means of PCR and RFLP analysis in 96 patients with HCC and 222 control subjects matched for age, sex, and ethnicity. Homozygous Ala/Ala carriers were 31% in the cases and 18% in the controls, which corresponds to an odds ratio (OR) of 2.89, with a 95% confidence interval (CI) of 1.47-5.68. Stratification into subgroups based on HCV infection status revealed an even more increased risk for homozygous Ala/Ala carriers with hepatitis C infection (38.2% in the cases versus 14.8% in the control subjects OR, 5.09; 95% CI, 1.76-14.66). Our findings provide further evidence of an association between the Ala-9Val MnSOD polymorphism and HCC occurrence in hepatitis C virus-infected Moroccan patients.     

Detection of the Free-Living Forms of Sulfide-Oxidizing Gill Endosymbionts in the Lucinid Habitat (Thalassia testudinum Environment)

Target DNA from the uncultivable Codakia orbicularis endosymbiont was PCR amplified from sea-grass sediment. To confirm that such amplifications originated from intact bacterial cells rather than free DNA, whole-cell hybridization (fluorescence in situ hybridization technique) with the specific probe Symco2 was performed along with experimental infection of aposymbiotic juveniles placed in contact with the same sediment. Taken together, the data demonstrate that the sulfide-oxidizing gill endosymbiont of Codakia orbicularis is present in the environment as a free-living uncultivable form.     

The natural antiviral and immune stimulant effects of Allium cepa essential oil onion extract against virulent Newcastle disease virus

Fifty broiler chicks were divided into five groups to study the antiviral and immune-stimulant effect of Allium cepa essential oils (ACEO). The effect of Allium cepa essential oils administration single or combined with NVD vaccine in broilers, more than one parameter was studied in this study i.e., the clinical symptoms that appeared on the chicks after the experimental infection with velogenic Newcastle disease virus, postmortem lesions, pathological lesions scoring, mortality rate (MR), and viral shedding, birds immunity was assessed by HI test and protection percent post-challenge with vNDV. Our result showed that mild clinical signs, lesion scoring, decreased viral shedding in ACEO treated groups 3 (G 3) more than control groups post-challenge with vNDV. Delayed onset of mild clinical signs in G3 followed by complete recovery 7th-day post-challenge (DPC). Low MR (40 and 0%) and high protection percent (100 and 60%) in ACEO treated G3 and G5, respectively. spleen, thymus, cecal tonsil, proventriculus, and cerebrum lesions scoring in G3 and G5 were significantly ((p ≤ 0.05).) lower than the control group, proving a decrease in NDV replication and effective antiviral activity of ACEO. HI titer significantly increased (p ≤ 0.05) In G3, G4 and G5 compared with control groups. There is no significant difference in HI titer in ACEO treated groups and vaccinated groups. In conclusion, oral administration of ACEO combined with NDV vaccines significantly reduces or eliminates lethal clinical signs, lesions, viral shedding, and enhances immune response and protection percent after vNDV challenge proving the natural antiviral and immune stimulant effect of ACEO onion extract. Implementing such a regime might aid NDV control in broiler flocks in endemic areas and reduce the epidemiological load of NDV in the environment.     

Ploidy effects on the relationship between floral phenotype,reproductive investment,and fitness in an autogamous species complex

Premise

The relationships between reproductive investment, phenotype, and fitness have been broadly studied in cross-pollinated plants in contrast to selfing species, which are considered less interesting in this area because they are supposed to be a dead end in any evolutionary pathway. Still, selfing plants are unique systems to study these questions since the position of reproductive structures and traits related to flower size play an important role in female and male pollination success.

Methods

Erysimum incanum s.l. is a selfing species complex that has three levels of ploidy (diploids, tetraploids, and hexaploids) and traits that are typically associated with the selfing syndrome. Here, we used 1609 plants belonging to these three ploidies to characterize the floral phenotype and spatial configuration of reproductive structures, reproductive investment (pollen and ovule production), and plant fitness. Then, we used structural equation modelling to analyze the relationship between all these variables across ploidy levels.

Results

An increase in ploidy level leads to bigger flowers with anthers exserted farther and more pollen and ovules. In addition, hexaploid plants had higher absolute values for herkogamy, which is positively correlated with fitness. Ovule production significantly mediated the natural selection acting on different phenotypic traits and pollen production, a pattern that is maintained across ploidies.

Conclusions

The changes in floral phenotypes, reproductive investment, and fitness with ploidy level suggest that genome duplication can be a driver for transitions in reproductive strategy by modifying the investment in pollen and ovules and linking them with plant phenotype and fitness.     

Molecular Characterization of the Principal Symbiotic Bacteria of the Weevil Sitophilus oryzae: A Peculiar G + C Content of an Endocytobiotic DNA

The principal intracellular symbiotic bacteria of the cereal weevil Sitophilus oryzae were characterized using the sequence of the 16S rDNA gene (rrs gene) and G + C content analysis. Polymerase chain reaction amplification with universal eubacterial primers of the rrs gene showed a single expected sequence of 1,501 bp. Comparison of this sequence with the available database sequences placed the intracellular bacteria of S. oryzae as members of the Enterobacteriaceae family, closely related to the free-living bacteria, Erwinia herbicola and Escherichia coli, and the endocytobiotic bacteria of the tsetse fly and aphids. Moreover, by high-performance liquid chromatography, we measured the genomic G + C content of the S. oryzae principal endocytobiotes (SOPE) as 54%, while the known genomic G + C content of most intracellular bacteria is about 39.5%. Furthermore, based on the third codon position G + C content and the rrs gene G + C content, we demonstrated that most intracellular bacteria except SOPE are A + T biased irrespective of their phylogenetic position. Finally, using the hsp60 gene sequence, the codon usage of SOPE was compared with that of two phylogenetically closely related bacteria: E. coli, a free-living bacterium, and Buchnera aphidicola, the intracellular symbiotic bacteria of aphids. Taken together, these results show a peculiar and distinctly different DNA composition of SOPE with respect to the other obligate intracellular bacteria, and, combined with biological and biochemical data, they elucidate the evolution of symbiosis in S. oryzae. Received: 8 September 1997 / Accepted: 24 October 1997     

What can a weevil teach a fly,and reciprocally? Interaction of host immune systems with endosymbionts in <Emphasis Type="Italic">Glossina</Emphasis> and <Emphasis Type="Italic">Sitophilus</Emphasis>

The tsetse fly (Glossina genus) is the main vector of African trypanosomes, which are protozoan parasites that cause human and animal African trypanosomiases in Sub-Saharan Africa. In the frame of the IAEA/FAO program ‘Enhancing Vector Refractoriness to Trypanosome Infection’, in addition to the tsetse, the cereal weevil Sitophilus has been introduced as a comparative system with regards to immune interactions with endosymbionts. The cereal weevil is an agricultural pest that destroys a significant proportion of cereal stocks worldwide. Tsetse flies are associated with three symbiotic bacteria, the multifunctional obligate Wigglesworthia glossinidia, the facultative commensal Sodalis glossinidius and the parasitic Wolbachia. Cereal weevils house an obligatory nutritional symbiosis with the bacterium Sodalis pierantonius, and occasionally Wolbachia. Studying insect host-symbiont interactions is highly relevant both for understanding the evolution of symbiosis and for envisioning novel pest control strategies. In both insects, the long co-evolution between host and endosymbiont has led to a stringent integration of the host-bacteria partnership. These associations were facilitated by the development of specialized host traits, including symbiont-housing cells called bacteriocytes and specific immune features that enable both tolerance and control of the bacteria. In this review, we compare the tsetse and weevil model systems and compile the latest research findings regarding their biological and ecological similarities, how the immune system controls endosymbiont load and location, and how host-symbiont interactions impact developmental features including cuticle synthesis and immune system maturation. We focus mainly on the interactions between the obligate symbionts and their host’s immune systems, a central theme in both model systems. Finally, we highlight how parallel studies on cereal weevils and tsetse flies led to mutual discoveries and stimulated research on each model, creating a pivotal example of scientific improvement through comparison between relatively distant models.     

Bacterial outer membrane vesicles,a potential vaccine candidate in interactions with host cells based

Both Gram-Positive and Gram-Negative bacteria can secrete outer membrane vesicles (OMVs) in their growth and metabolism process. Originally, OMVs were considered as a by-product of bacterial merisis. However, many scientists have reported the important role of OMVs in many fields recently. In this review, we briefly introduce OMVs biological functions and then summarize the findings about the OMVs interactions with host cells. At last, we will make an expectation about the prospects of the application of OMVs as vaccines.     

Enhancement of somatic embryogenesis frequency by gibberellic acid in fennel

The effect of GA₃ on somatic embryogenesis from petiole fragments excised from micropropagated fennel plantlets was studied. Explants were maintained for 4 weeks on an induction medium containing, 2,4-d and kinetin and were then transferred to a medium devoid of these growth regulators to allow embryo development. The addition of autoclaved or filter-sterilized GA₃ to the induction medium or to the embryo development medium increased the number of embryogenic explants. No positive effect was observed when GA₃ was added to the micropropagation medium of the mother plantlets. Gibberellic acid also counteracted the inhibiting effect of continuous light on the number of embryogenic explants. Moreover, the embryogenic frequency of petiole explants from several genotypes previously considered as poorly reacting was highly enhanced by GA₃.Abbreviations BA 6-benzyladenine - 2,4-d 2,4-dichlorophenoxyacetic acid - GA₃ Gibberellic acid - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid     

Widespread occurrence of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase among gram-positive bacteria.

The non-phosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPDHN, NADP+-specific, EC 1.2.1.9) is present in green eukaryotes and some Streptococcus strains. The present report describes the results of activity and immunoblot analyses, which were used to generate the first survey of bacterial GAPDHN distribution in a number of Bacillus, Streptococcus and Clostridium strains. Putative gapN genes were identified after PCR amplification of partial 700-bp sequences using degenerate primers constructed from highly conserved protein regions. Alignment of the amino acid sequences of these fragments with those of known sequences from other eukaryotic and prokaryotic GAPDHNs, demonstrated the presence of conserved residues involved in catalytic activity that are not conserved in aldehyde dehydrogenases, a protein family closely linked to GAPDHNs. The results confirm that the basic structural features of the members of the GAPDHN family have been conserved throughout evolution and that no identity exists with phosphorylating GAPDHs. Furthermore, phylogenetic trees generated from multiple sequence alignments suggested a close relationship between plant and bacterial GAPDHN families.