Isoenzyme variation patterns and species concept in Astragalus gossypinus and Astragalus persicus complexes (Fabaceae) in Iran

Isoenzyme electrophoresis was employed to examine the relationships of 21 individuals representing four populations of Astragalus gossypinus complex as well as 20 individuals representing five populations of Astragalus persicus complex. A total of 27 bands from three enzyme systems (superoxide dismutase, esterase, and peroxidase) were obtained. UPGMA clustering method resulted in two distinct clusters for different populations corresponding to the two species complexes analysed. In both species, populations distributed on Alborz mountain range in northern Iran form separated clusters from those distributed on Zagros mountain range in the West. The results also show that both species complexes exhibit a high diversity based on Shannon–Weaver diversity index (H′) compared with other species of Astragalus reported previously. The mean number of bands per each presumed isoenzyme ranges from 2.14 to 3.57. The value of Euclidean distance ranges from 1.251 to 3.152. Our data suggest that both species should be circumscribed wider than that treated by most taxonomists, and several taxonomic names should be reduced under synonymy of the corresponding species.     

Antioxidant metabolism and oxidative damage in Anthemis gilanica cell line under fast clinorotation

Plant Cell, Tissue and Organ Culture (PCTOC) - Clinostat is a device often used for applying microgravity analogs in gravitational biology studies. It can constantly change the direction of the...     

Nuclear delivery mechanism of herpes simplex virus type 1 genome

Herpes simplex virus type 1 (HSV-1) is a widespread human pathogen infecting more than 80% of the population worldwide. Its replication involves an essential, poorly understood multistep process, referred to as uncoating. Uncoating steps are as follows: (1) The incoming capsid pinpoints the nuclear pore complex (NPC). (2) It opens up at the NPC and releases the highly pressurized viral genome. (3) The viral genome translocates through the NPC. In the present review, we highlight recent advances in this field and propose mechanisms underlying the individual steps of uncoating. We presume that the incoming HSV-1 capsid pinpoints the NPC by hydrophobic interactions and opens up upon binding to NPC proteins. Genome translocation is initially pressure-driven.     

Synaptotagmin perturbs the structure of phospholipid bilayers

Synaptotagmin I (syt), an integral protein of the synaptic vesicle membrane, is believed to act as a Ca2+ sensor for neuronal exocytosis. Syt's cytoplasmic domain consists largely of two C2 domains, C2A and C2B. In response to Ca2+ binding, the C2 domains interact with membranes, becoming partially embedded in the lipid bilayer. We have imaged syt C2AB in association with lipid bilayers under fluid, using AFM. As expected, binding of C2AB to bilayers required both an anionic phospholipid [phosphatidylserine (PS)] and Ca2+. C2AB associated with bilayers in the form of aggregates of varying stoichiometries, and aggregate size increased with an increase in PS content. Repeated scanning of bilayers revealed that as C2AB dissociated it left behind residual indentations in the bilayer. The mean depth of these identations was 1.81 nm, indicating that they did not span the bilayer. Individual C2 domains (C2A and C2B) also formed aggregates and produced bilayer indentations. Binding of C2AB to bilayers and the formation of indentations were significantly compromised by mutations that interfere with binding of Ca2+ to syt or reduce the positive charge on the surface of C2B. We propose that bilayer perturbation by syt might be significant with respect to its ability to promote membrane fusion.     

The Modulatory Effect of Metabotropic Glutamate Receptor Type-1α on Spike-Wave Discharges in WAG/Rij Rats

Modulatory function of metabotropic glutamate type 1 (mGlu1) receptors plays a crucial role in the pathophysiology of some neurological disorders, including schizophrenia and epilepsy. In this study, the expression of mGlu1α receptors in the thalamic nuclei was assessed during development of absence seizures in the WAG/Rij rats, a valid genetic animal model of absence epilepsy. In addition, the effect of pharmacological modulation of mGlu1α receptors in the laterodorsal (LD) nucleus of the thalamus on the characteristic features of bioelectrical brain activities in the WAG/Rij rats was assessed. The expression of mGlu1α receptors in the LD was assessed in four experimental groups of both WAG/Rij and Wistar rats with 2 and 6 months of age. Agonist and antagonist of mGlu1α receptors were infused in LD in the six months old WAG/Rij (epileptic) rats. The protein level of mGlu1α receptors in the thalamus of the 6-month-old WAG/Rij rats was lower than non-epileptic animals. In addition, the distribution of mGlu1α receptors in different thalamic nuclei was lower in the 6-month-old WAG/Rij compared to age-matched Wistar rats. The gene expression of mGlu1α receptor was also significantly lower in 6-month-old WAG/Rij rats in the LD compared to other animal groups. The microinjection of mGlu1α receptors agonist and antagonist in the LD reduced the duration of spike-wave discharges (SWDs) and increased the amplitude and duration of SWDs, respectively, in 6-month-old WAG/Rij rats. The alterations of mGlu1α receptors expression in the thalamus of epileptic WAG/Rij rats as well as its modulatory effects in the generation of SWDs suggest the potential of mGlu1 receptors as a therapeutic target in absence epilepsy.     

A single dominant gene for Fusarium wilt resistance in protoplast-derived tomato plants

Summary Autotetraploids were established from 8 diploid wild species of section Arachis. In all the autotetraploids the chromosomes paired largely as bivalents even though they possess the ability to pair as multivalents. Pollen and pod fertility in the C₁ generation were not directly associated with chromosome pairing. The C₂ generation autotetraploids showed a gradual increase in bivalent associations and pollen and pod fertility. The identification of two genomes, A and B, in the diploid species and in the tetraploid, A. hypogaea, of the section Arachis, a fairly good crossability, and the type of chromosome associations observed in hybrids between A. hypogaea and the autotetraploids of wild Arachis species indicated good prospects of utilizing autotetraploids as genetic bridges in transferring desired traits from these taxa into groundnut.Submitted as Journal Article No. 516 by International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)     

State-of-the-Art Review of Biocementation by Microbially Induced Calcite Precipitation (MICP) for Soil Stabilization

Biocementation is a recently developed new branch in geotechnical engineering that deals with the application of microbiological activity to improve the engineering properties of soils. One of the most commonly adopted processes to achieve soil biocementation is through microbially induced calcite precipitation (MICP). This technique utilizes the metabolic pathways of bacteria to form calcite (CaCO₃) that binds the soil particles together, leading to increased soil strength and stiffness. This paper presents a review of the use of MICP for soil improvement and discusses the treatment process including the primary components involved and major affecting factors. Envisioned applications, potential advantages and limitations of MICP for soil improvement are also presented and discussed. Finally, the primary challenges that lay ahead for the future research (i.e. treatment optimization, upscaling for in situ implementation and self-healing of biotreated soils) are briefly discussed.