Study of gene expression and steviol glycosides accumulation in Stevia rebaudiana Bertoni under various mannitol concentrations

Molecular Biology Reports - Stevia rebaudiana produces sweet steviol glycosides that are 300 times sweeter than sugar and have the beneficial effects on human health including anti-hyperglycaemic....     

Effects of Metarhizium anisopliae on searching,feeding and predation by Orius albidipennis (Hem., Anthocoridae) on Thrips tabaci (Thy., Thripidae) larvae

The generalist predator Orius albidipennis Reut. (Hem., Anthocoridae) and entomopathogenic fungus Metarhizium anisopliae (Metchnikoff) Sorokin (Ascomycota: Clavicipitaceae) are important biocontrol agents of Thrips tabaci Lindeman (Thys., Thripidae) in most greenhouses. In this study, we estimated searching time, feeding time and predation rate in O. albidipennis feeding on untreated and treated thrips larvae which had been inoculated with three concentrations of M. anisopliae V275 at four time intervals; 0, 24, 48 and 72 h after infestation. Applied concentrations were 1×10³, 2×10⁴ and 2×10⁵ conidia/mL which roughly correspond to the LC₂₅, LC₅₀ and LC₇₅ for second instar-larvae. O. albidipennis responded to the presence of the M. anisopliae on the treated hosts by increasing the searching time and decreasing feeding time and predation rate levels. It was also able to detect and avoid treated patches.     

Effect of landscape features on genetic structure of the goitered gazelle (<Emphasis Type="Italic">Gazella subgutturosa</Emphasis>) in Central Iran

The populations of goitered gazelle suffered significant decline due to natural and anthropogenic factors over the last century. Investigating the effects of barriers on gene flow among the remaining populations is vital for conservation planning. Here we adopted a landscape genetics approach to evaluate the genetic structure of the goitered gazelle in Central Iran and the effects of landscape features on gene flow using 15 polymorphic microsatellite loci. Spatial autocorrelation, isolation by distance (IBD) and isolation by resistance (IBR) models were used to elucidate the effects of landscape features on the genetic structure. Ecological modeling was used to construct landscape permeability and resistance map using 12 ecogeographical variables. Bayesian algorithms revealed three genetically homogeneous groups and restricted dispersal pattern in the six populations. The IBD and spatial autocorrelation revealed a pattern of decreasing relatedness with increasing distance. The distribution of potential habitats was strongly correlated with bioclimatic factors, vegetation type, and elevation. Resistance distances and graph theory were significantly related with variation in genetic structure, suggesting that gazelles are affected by landscape composition. The IBD showed greater impact on genetic structure than IBR. The Mantel and partial Mantel tests indicated low but non-significant effects of anthropogenic barriers on observed genetic structure. We concluded that a combination of geographic distance, landscape resistance, and anthropogenic factors are affecting the genetic structure and gene flow of populations. Future road construction might impede connectivity and gene exchange of populations. Conservation measures on this vulnerable species should consider some isolated population as separate management units.     

Nest-site selection and its impact on breeding success of the Lesser Kestrel,Falco naumanni,in the North of Iran (Aves: Falconiformes)

The Lesser Kestrel (Falco naumanni) is a small migratory falcon which nests coloni- ally on inland cliffs and ruined buildings. Bandar Turkman city holds one of the most important breeding colonies in Iran. It nests in holes in roofs, walls or on ledges of buildings throughout of the city. We tried to find out whether there is a relationship between nest-site selection and breeding success. Although height from the ground is the most important factor in nest-site selection by F. naumanni, height from the floor and distance to the nearest neighbour are other main factors which affect breeding success. This could be the result of accessibility by human and natural predators such as domestic cats which threaten nests. The number of possible nest-sites in the study area is limited as many old, ruined buildings are being replaced by new construc- tions; this colonially breeding bird species therefore suffers from a lack of highly suitable nest-sites and this directly affect breeding success.     

The Impact of Myeloperoxidase and Activated Macrophages on Metaphase II Mouse Oocyte Quality

Myeloperoxidase (MPO), an abundant heme-containing enzyme present in neutrophils, monocytes, and macrophages, is produced in high levels during inflammation, and associated with poor reproductive outcomes. MPO is known to generate hypochlorous acid (HOCl), a damaging reactive oxygen species (ROS) utilizing hydrogen peroxide (H₂O₂) and chloride (Cl^-). Here we investigate the effect of activated immune cells and MPO on oocyte quality. Mouse metaphase II oocytes were divided into the following groups: 1) Incubation with a catalytic amount of MPO (40 nM) for different incubation periods in the presence of 100 mM Cl^- with and without H₂O₂ and with and without melatonin (100 μM), at 37°C (n = 648/648 total number of oocytes in each group for oocytes with and without cumulus cells); 2) Co-cultured with activated mouse peritoneal macrophage and neutrophils cells (1.0 x 10⁶ cells/ml) in the absence and presence of melatonin (200 μM), an MPO inhibitor/ROS scavenger, for different incubation periods in HTF media, at 37°C (n = 200/200); 3) Untreated oocytes incubated for 4 hrs as controls (n = 73/64). Oocytes were then fixed, stained and scored based on the microtubule morphology and chromosomal alignment. All treatments were found to negatively affect oocyte quality in a time dependent fashion as compared to controls. In all cases the presence of cumulus cells offered no protection; however significant protection was offered by melatonin. Similar results were obtained with oocytes treated with neutrophils. This work provides a direct link between MPO and decreased oocyte quality. Therefore, strategies to decrease MPO mediated inflammation may influence reproductive outcomes.     

Irisin induces trophoblast differentiation via AMPK activation in the human placenta

Irisin, an adipokine, regulates differentiation and phenotype in various cell types including myocytes, adipocytes, and osteoblasts. Circulating irisin concentration increases throughout human pregnancy. In pregnancy disorders such as preeclampsia and gestational diabetes mellitus, circulating irisin levels are reduced compared to healthy controls. To date, there are no data on the role and molecular function of irisin in the human placenta or its contribution to pathophysiology. Aberrant trophoblast differentiation is involved in the pathophysiology of preeclampsia. The current study aimed to assess the molecular effects of irisin on trophoblast differentiation and function. First-trimester placental explants were cultured and treated with low (10 nM) and high (50 nM) physiological doses of irisin. Treatment with irisin dose-dependently increased both in vitro placental outgrowth (on Matrigel™) and trophoblast cell-cell fusion. Adenosine monophosphate-activated protein kinase (AMPK) signaling, an important regulator of cellular energy homeostasis that is involved in trophoblast differentiation and pathology, was subsequently investigated. Here, irisin exposure induced placental AMPK activation. To determine the effects of irisin on trophoblast differentiation, two trophoblast-like cell lines, HTR-8/SVneo and BeWo, were treated with irisin and/or a specific AMPK inhibitor (Compound C). Irisin-induced AMPK phosphorylation in HTR-8/SVneo cells. Additionally, as part of the differentiation process, integrin switching from α6 to α1 occurred as well as increased invasiveness. Overall, irisin promoted differentiation in villous and extravillous cell-based models via AMPK pathway activation. These findings provide evidence that exposure to irisin promotes differentiation and improves trophoblast functions in the human placenta that are affected in abnormal placentation.     

Sublethal effects of pyriproxyfen,a juvenile hormone analogue,on Plutella xylostella (Lepidoptera: Plutellidae): life table study

The sublethal effects of pyriproxyfen (PYR, a juvenile hormone analogue) were investigated for two consecutive generations on life-history parameters, such as developmental time, pupal weight, fecundity, fertility and longevity of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). After topical application bioassay of third instar larvae, the LC₂₅ and LC₅₀ values (as sublethal doses) were determined to be 1.49 and 2.01 μg/μl, respectively. The results showed that the egg incubation period, larval and pupal duration times and oviposition period were increased in treated groups compared with the control (treated with distilled water). Pupal weight, adult longevity, fecundity and fertility were significantly reduced in the treatment groups compared with the control. Using the age-stage, two-sex life table analysis, we found that the intrinsic rate of increase (r), finite rate of increase (λ), gross reproduction rate (GRR) and net reproductive rate (R ₀) significantly decreased while the mean generation time (T) and doubling time (DT) increased in two treatment groups compared with the control. In addition, administration of PYR induced morphogenetic abnormalities including untanned pupae, larval–pupal intermediates and various defective adults. The LC₅₀ value was more effective on all of the above biological characteristics than the LC₂₅ for both generations, although parents were more affected than the offspring. In general, our results revealed that PYR was highly effective against P. xylostella in the laboratory both directly (causing mortality) and indirectly (disruption of normal growth and development). We conclude that PYR is an excellent candidate for suppressing populations of P. xylostella through its sublethal effects.     

Clinical grade cultivation of human Schwann cell, by the using of human autologous serum instead of fetal bovine serum and without growth factors

Clinical grade cultivation of human schwann cell by the utilization of human autologous serum instead of fetal bovine serum, and also avoiding any growth factors, can increase safety level of this procedure in cases of clinical cell transplantation. The aim of this study was demonstration of the feasibility of clinical grade schwann cell cultivation. In this experimental study after obtaining consent from close relatives we harvested 10 sural nerves from brain death donors and then cultured in 10 seperated culture media plus autologous serum. We also prepared autologous serum from donor??s whole blood. Then cultured cells were evaluated by S100 antibody staining for both morphology and purity. Cell purity range was from 97% to 99% (mean?=?98.11?±?0.782%). Mean of the cell count was 14,055.56?±?2,480.479 per micro liter. There was not significant correlation between cell purity and either the culture period or the age of donors (P?>?0.05). The spearman correlation coefficient for the cell purity with the period or the age of donors was 0.21 and 0.09, respectively. We demonstrated the feasibility of clinical grade schwann cell cultivation by the using of human autologous serum instead of fetal bovine serum and also without the using of growth factors. We also recommended all cell preparation facilities to adhere to the GMP and other similar quality disciplines especially in the preparation of clinically-used cell products.