Roles of BdUNICULME4 and BdLAXATUM‐A in the non‐domesticated grass Brachypodium distachyon

In cultivated grasses, tillering, spike architecture and seed shattering represent major agronomical traits. In barley, maize and rice, the NOOT‐BOP‐COCH‐LIKE (NBCL) genes play important roles in development, especially in ligule development, tillering and flower identity. However, compared with dicots, the role of grass NBCL genes is underinvestigated. To better understand the role of grass NBCLs and to overcome any effects of domestication that might conceal their original functions, we studied TILLING nbcl mutants in the non‐domesticated grass Brachypodium distachyon. In B. distachyon, the NBCL genes BdUNICULME4 (CUL4) and BdLAXATUM‐A (LAXA) are orthologous, respectively, to the barley HvUniculme4 and HvLaxatum‐a, to the maize Zmtassels replace upper ears1 and Zmtassels replace upper ears2 and to the rice OsBLADE‐ON‐PETIOLE1 and OsBLADE‐ON‐PETIOLE2/3. In B. distachyon, our reverse genetics study shows that CUL4 is not essential for the establishment of the blade–sheath boundary but is necessary for the development of the ligule and auricles. We report that CUL4 also exerts a positive role in tillering and a negative role in spikelet meristem activity. On the other hand, we demonstrate that LAXA plays a negative role in tillering, positively participates in spikelet development and contributes to the control of floral organ number and identity. In this work, we functionally characterized two new NBCL genes in a context of non‐domesticated grass and highlighted original roles for grass NBCL genes that are related to important agronomical traits.     

First characterization of congenital myasthenic syndrome type 5 in North Africa

Molecular Biology Reports - Congenital myasthenic syndromes (CMS) are associated with defects in the structure and the function of neuromuscular junctions. These rare disorders can result from...     

Antibacterial and antifungal activities of teucrium royleanum (Labiatea)

The crude methanolic extract and subsequent fractions of Teucrium royleanum (Labiatea) were screened for antibacterial and antifungal activities. Against tested pathogens, crude extract and subsequent fractions demonstrated moderate to excellent antibacterial activities. Highest antibacterial activity was displayed by the ethyl acetate fraction against S. typhi (100%), against E.coli (76.7%) and against P. aerugenosa (70.8%) followed by the chloroform fraction against S. typhi (85.7%). Similarly, the crude extract and its subsequent fractions showed mild to excellent activities in the antifungal bioassay with maximum antifungal activity against M. canis (87%) by the chloroform fraction followed by the ethyl acetate (71%) and n-butanol (70%) fractions.     

The Highly Conserved Layer-3 Component of the HIV-1 gp120 Inner Domain Is Critical for CD4-Required Conformational Transitions

The trimeric envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) mediates virus entry into host cells. CD4 engagement with the gp120 exterior envelope glycoprotein subunit represents the first step during HIV-1 entry. CD4-induced conformational changes in the gp120 inner domain involve three potentially flexible topological layers (layers 1, 2, and 3). Structural rearrangements between layer 1 and layer 2 have been shown to facilitate the transition of the envelope glycoprotein trimer from the unliganded to the CD4-bound state and to stabilize gp120-CD4 interaction. However, our understanding of CD4-induced conformational changes in the gp120 inner domain remains incomplete. Here, we report that a highly conserved element of the gp120 inner domain, layer 3, plays a pivot-like role in these allosteric changes. In the unliganded state, layer 3 modulates the association of gp120 with the Env trimer, probably by influencing the relationship of the gp120 inner and outer domains. Importantly, layer 3 governs the efficiency of the initial gp120 interaction with CD4, a function that can also be fulfilled by filling the Phe43 cavity. This work defines the functional importance of layer 3 and completes a picture detailing the role of the gp120 inner domain in CD4-induced conformational transitions in the HIV-1 Env trimer.     

Impact of winter pruning of pomegranate trees on Aphis punicae (Hemiptera,Aphididae) and its natural enemies in Tunisia

Winter pruning is a cultural practice used to modify vegetative growth, which is likely to affect the development of pests. However, it has been poorly defined as a cultural method for diminishing the population levels of the pomegranate aphid Aphis punicae (Hemiptera, Aphididae) in pomegranate orchards. This study aimed to evaluate the impact of winter pruning of pomegranate on A. punicae population and their natural enemies. The results showed that winter pruning significantly decreased the population of A. punicae (p < 0.05) in pomegranate. Also, number of natural enemies decreased in pomegranate trees after winter pruning. This technical practice affects the number of winged and wingless individuals, the mean relative growth rate, the specific age of the population and the infestation rate. Winter pruning for A. punicae control in pomegranate orchards is highly recommended.     

Associations of rs1883832 and rs4810485 polymorphisms of CD40 gene with myocardial infarction in the Tunisian population

Context: Cluster of differentiation 40 (CD40), and its ligand CD40L, are major co-stimulatory molecules whose interactions are important in both cellular and humoral immunity, and has been suggested to play a role in the pathogenesis of acute coronary syndrome.

Objective: The aim of this study was to examine the association of CD40 polymorphisms (-1?C>T (rs1883832) and 945G>T (rs4810485)) and myocardial infarction (MI), and to test the association of CD40 gene haplotypes with MI in Tunisians.

Materials and methods: Three hundred and fifty MI patients and 301 apparently healthy controls were included in the study. The polymorphisms of CD40 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results: There were significant differences in the genotype and allele frequencies of CD40 gene -1?C>T (rs1883832) polymorphism between cases and controls. Stratifying according to gender, the association between the TT genotype and MI was statistically significant in males, only. Haplotype analysis revealed that the C-T and T-G haplotypes were associated with an increased risk of MI (p?=?0.012 and p?<?0.001, respectively).

Conclusions: Our work showed a significant association between the -1?C>T (rs1883832) polymorphism of the CD40 gene and MI in the Tunisians.     

Is it possible to calibrate the pollution level of the region of Algiers (Mediterranean Sea) by exploiting marine macrophytes?

In the absence of water-quality data, a biological indicator is the only way to estimate the pollution level. Samples of macrophytes from exposed shallow rocky substrata of the region of Algiers (Algeria, Mediterranean Sea) were collected in supposedly (in the absence of available pollution data) polluted and pristine waters. These samples were compared to a set of samples spanning a known pollution gradient found near Marseilles (France) and to some samples from a variety of other Mediterranean localities. All samples were collected in similar conditions. The diversity point (i.e., the number of species per sample) was not greater at Cherchell (control site) than at the three sites in the Bay of Algiers. Analysis of the dataset was successful in ranking the Algerian sites, but failed to calibrate the pollution level of the Algerian sites by inserting Algerian samples within the pollution gradient of Marseilles. In contrast, regional characteristics of the macrophyte communities appear to be largely prevalent. This means that water-quality biological indicators and indices based upon marine macrophytes, at least for the open waters and exposed shallow Mediterranean habitats studied here, could be reliable within a given region, but may require validation and/or adjustment, perhaps considerable, for other regions.     

Estimation of aboveground biomass in conserved areas of Stipa tenacissima L. stands in the high steppes of western Algeria by mean of the Landsat 8 imagery‐based vegetation indices

The main aim of this paper was to evaluate the use of OLI spectral data as a tool to assess the steppe vegetation in a conservation context. The field sampling was conducted for two specific areas of treatment (a) an exclosure area and (b) a free grazing area. After testing several vegetation indices (VIs), the optimal results were obtained for the Normalised Difference Vegetation Index (NDVI)‐based aboveground biomass model with r² = 0.61 and r² = 0.72 for total and perennial biomass, respectively. No difference between observed and predicted total and perennial biomass was found (p = 0.700 and p = 0.306, respectively). The comparison between the two treatments using the field sampling revealed a significant difference on total plant cover (p = 0.016) and total biomass (p = 0.005), with a plant cover of 50.6% and a biomass of 325.771 kg dry matter per hectare (kg DM ha^?1) on average in grazed area and 66.9%, 1,407.869 kg DM ha^?1 in exclosure. Finally, a concordance is noted between the results obtained by the NDVI‐based biomass model and the field sampling‐based biomass.