Iranian Journal of Biotechnology
Volume:10 Issue: 3, Summer 2012

MdMYB10 gene expression results in accumulation of anthocyanin in many tissues including flesh of apple fruit. The MdMYB1 and MdMYBA genes are close homologues to MdMYB10 gene and both are responsible for red color phenotype in apple fruit skin. In the current study، an apple genome sequence draft analysis indicated that these three genes are located in a unique contig. Further analysis suggested that these homologues are alleles of a single locus and they differ in a repeated sequence of the promoter region. This repeated sequence ensures high expression level of MdMYB10 in most of the plant tissues while MdMYB1 and MdMYBA alleles lack such a repeated sequence in their promoters and their expression is confined to the fruit skin. Also، we suggest a tissue- and genome-specific expression pattern for these three alleles considering our data and other recent publications. No variation was detected in the sequence or in the number of repeats of MdMYB10 promoter in Iranian red flesh apple geo-variants، pointing that the number of repeat is not related to flesh color intensity or variation، and the repeat elements have occurred once during the evolution.

An efficient and reproducible in vitro protocol for large-scale multiplication of Liquorice (Glycyrrhiza glabra L.) has been described. Multiple shoots formation was significantly influenced by growth regulators، photoperiod، explant position، season of explant collection and culture passage. Nodal explants were collected at monthly intervals to initiate in vitro cultures. The highest bud-break (86. 6%) with the longest shoot length (8. 0 cm) and maximum number of shoots (3. 0) was obtained when middle order nodes (3rd to 5th node from apex) collected between May to August were inoculated on MS medium supplemented with 6-Benzylaminopurine (2. 0 mg/l) + a-naphthalene acetic acid (0. 5 mg/l) under photoperiod of 16/8 h (light/dark cycle). The induction of multiple shoots was also affected by photoperiod and subculture cycle. Multiple shoots formation increased from the first (2. 2) to the fourth subculture (6. 6). The in vitro regenerated shoots were induced on half strength MS medium enriched with 1. 0 mg/l IAA resulting early rooting and maximum root growth. Plantlets were hardened and successfully established in the soil. Concentration of chlorophyll، total sugars، reducing sugars and proteins were estimated in leaf tissues from both in vivo and in vitro raised plants. Chlorophyll content was higher in in vivo plants، whereas other three components were higher in micropropagated plants. The present optimized micropropagation protocol offers the possibility of germplasm conservation and mass cultivation of this important medicinal plant.

The Box-Wilson central composite design (CCD) based on response surface methodology (RSM) was used for ethanol fermentation using very high gravity (VHG) finger millet hydrolysate. Optimized process variables were namely، concentrations of yeast extract، magnesium sulphate and pH of the medium. High gravity mashes (>300 g dissolved solids per liter) were prepared by a thermo-stable a-amylase، followed by simultaneous saccharification and fermentation (SSF) at 30ºC for 60 h. Ethanol concentration as high as 13. 66% (v/v) was obtained after optimizing the variables. The coefficient of determination (R2) value of 0. 9808 indicates the goodness of fit for regression model. The predicted values for optimization process conditions were in good agreement with experimental data. The optimum values for tested variables were yeast extract 7. 13 (g/l) magnesium sulphate 23. 32 mM and pH 4. 8. Verification of the model indicated no significant difference between predicted and observed values.

Nowadays، the clustering of proteins and enzymes in particular، are one of the most popular topics in bioinformatics. Increasing number of chitinase genes from different organisms and their sequences have been identified. So far، various mathematical algorithms for the clustering of chitinase genes have been used but most of them seem to be confusing and sometimes insufficient. In the present study، as a first step، different amino acids participating in panoply of chitinases، as a model protein، obtained from the NCBI GenBank، were digitized. Digitized data were normalized to the signal energy. Normalized data decomposed using mother wavelet bior 5. 5 to approximation (a1) and details (d1)، at the first level. Corresponded coefficients have been obtained and cross correlation between normalized، a1 and d1 coefficients of amino acid sequences were calculated. Maximum correlation was selected as similarity index and corresponded cladogram trees were made. The results of this study showed that more optimal and reliable cladogram tree can be produced and better discrimination observed from d1 coefficients compared to normalized sequences and opposed to a1 coefficients. Using suggested approach، the cladogram tree made from d1 coefficients not only had more validity but also the drawback of the classic cladogram tree has been improved.

A wide range of materials and scaffolding fabrication methods for bone tissue engineering have been explored recently. Fiber reinforced polymers (FRP) system appears to be a suitable system. By the exclusive use of biocompatible or bio-absorbable polymers and fibers، novel generation of scaffolds for applications in tissue engineering can be prepared. Mulberry Silk as highlighted natural fiber with its specific economic، mechanical and biological properties has been used for fabrication FRP scaffolds. In this study FRP scaffolds prepared by a combination of silk fibroin polymer، which is another configuration of silk fibers as a porous matrix and silk fibers as the reinforcement element. FRP scaffolds have been fabricated by the freeze-drying method. Microstructure has been analyzed by scanning electron microscopy and the results show an integrative structure. Mechanical properties have been evaluated by universal testing machine. Compressive mechanical modules as well as strength of FRP scaffolds increased about three times in magnitude in comparison with pure fibroin scaffolds. FRP scaffolds had a compressive module of ~3. 6 MPa. Osteoblast viability and attachment on FRP scaffolds were investigated in vitro by MTT assay، which showed no cytotoxic response. Additionally، based on SEM results it is concluded that FRP scaffolds provide a good environment for osteoblast attachment.

In the present study، properties of silver nanoparticles (AgNPs) such as average size، size distribution and morphology were investigated by Tollens، polysaccharide، modified polysaccharide and microbial methods. The synthesized AgNPs were characterized by UV-visible spectroscopy، scanning electron microscopy (SEM)، transmission electron microscopy (TEM)، dynamics light scattering (DLS) and energy dispersive X-ray (EDX) analyses. Analysis of reaction mixtures confirmed that Tollens، polysaccharide and modified polysaccharide methods generated smaller AgNPs with better size distribution as compared to that produced in microbial method. The average size of produced AgNPs by Tollens، polysaccharide and modified polysaccharide were 42، 30 and 20 nm respectively. Moreover، microbial method generated AgNPs with average size of 54 nm in the case of cell-free filtrate mediated synthesis and 84 nm in case of the supernatant mediated synthesis. Analysis of fungus-mediated synthesis of AgNPs showed that the size distribution of AgNPs produced by supernatant is narrower than that produced by filtrate. Also، cell-free filtrate resulted in the formation of smaller AgNPs with average size of 59 nm compared to the supernatant. The comparative analysis of produced AgNPs by the above mentioned methods confirmed that modified polysaccharide method led to the formation of AgNPs with smallest size and highest productivity.

Until recently، Cryptosporidium was thought to be a single species genus. Molecular studies now show that there are at least 10 valid species of this parasite. Among them، two morphologically identical species، C. hominis and C. parvum are the most pathogenic identified to date and share 97% of identical genomes. Post-genomic analyses is therefore necessary to explore further the genetic variations among them. During this study، a comparative proteomic approach was applied to analyze the differential expression of sporozoite proteins in both C. hominis and C. parvum. Using 2-DE gels with different pH ranges (3-10 and 4-7) and automated three dimensional (3D) image analyses، a total of 20 protein spots were shown to be differentially expressed between the two species. Mass spectrometry analyses of these spots identified one hypothetical protein، however، identification of the remaining spots was unsuccessful. Further characterization of this hypothetical protein along with all differentially expressed proteins could provide crucial information in understanding the differential biology of Cryptosporidium spp.

The effects of non-starch polysaccharide (NSP) content of wheat and xylanase supplementation (XS) of the diet، on intestinal enzyme activity (amylase، aminopeptidase and lipase)، fat digestibility and ileal viscosity of laying hens has been studied. Two hundred forty Hy-Line W-36 layer from 20 to 25 week of age were studied under a factorial experiment (4×2) in completely randomized design with 8 treatments including four levels of wheat (0، 23، 46 and 69%) corresponding to a dietary xylose content of 1. 9، 2. 1، 2. 3 and 2. 5% and two levels of xylanase (none or added at the dosage recommended by the supplier). Each treatment was replicated five times each with six hens. Wheat inclusion in the diet increased amylase and lipase activity in the duodenum and jejunum، respectively (P<0. 001). Wheat inclusion، increased ileal viscosity while adding xylanase to diet، reduced it (P<0. 001). Fat digestibility was decreased by wheat increment levels (P<0. 001). The pH of the digesta content in different segments of gastro-intestinal tract (GIT) was not affected by wheat levels or XS، except for cecum that decreased with increasing the level of wheat. Relative weight and length of duodenum، jejunum and ileum were not affected by dietary treatment. Results suggested that wheat inclusion at high levels increased endogenous enzyme activity but could not alleviate the adverse effect of NSP content of diet on fat digestibility.

The primary aim of this study was to investigate the status of RANKL6-7 gene polymorphism in patients with chronic (mild، moderate، severe) and aggressive periodontitis as well as healthy controls. We examined 80 patients for the RANKL6-7 polymorphisms (rs1054016 and rs9567000). Polymorphism was determined by polymerase chain reaction (PCR) followed by direct sequencing. No statistically significant association was found between the polymorphism in the RANKL 7 gene and periodontal disease (P<0. 55). There was also no polymorphic allele observed in RANKL 6 gene of the study population. We found no association between the studied RANKL polymorphisms and chronic/aggressive periodontitis.