مجله پژوهش های سلولی مولکولی (زیست شناسی ایران)
سال بیست و هفتم شماره 2 (تابستان 1393)

Microorganisms as potent eco-friendly green nanofactories have the potential to control the size and shape of biological nanostructures. Zinc oxide nanoparticles have found much potential in pharmaceuticals، biological sciences، biomedical sciences and therapy diagnosis. In the current investigation، the native yeast strains screen as potent biocatalysts for extracelluar synthesis of ZnO nanoparticles. Using enrichment culture، 7 yeast strains isolated from collecting soil samples from Cooper mines. Among them، the strain MY2 had a great potential for extracellular synthesis of ZnO nanoparticles. The isolated yeast strain selected and identified as Candida sp. strain MY2 (GenBank accession number KF560329) based on phenotypic and molecular characteristics. The production of ZnO nanoparticles in bioconversion mixture was studied using UV-vis spectroscopy. The XRD analysis confirmed that the produced ZnO nanoparticles are in the form of nanocrystaline. Scanning electron microscopy (SEM) and Particle size analyzer were used to carry out surface morphology and size distribution characteristics of the produced nanoparticles. The results obtained in this investigation showed the potential of yeast strain of Candida sp. MY2 to produce fast and extracellular of ZnO nanoparticles and it can be used as safe and cost effective biocatalyst to catalysis ZnO nanoparticles with narrow particle size distribution in the range of 5-50 nm and an average size 23. 5 nm after incubation for 8 hours.

Heavy metals such as cadmium، mercury، nickel and Oxyanions for example chromate and tellurite are toxic elements that entering into the environment in different ways and are harmful for biological systems، especially humans، animals and plants، so to remove it from the environment is essential. Microorganisms، especially bacteria have a very important role in the biological removal of heavy metals and are used in biotechnology. In this study، has been done the counting intestinal coli forms and heavy metals resistant strains isolated from industrial wastewater، domestic wastewater and various parts of the wastewater treatment system of Arak city. In this study 4 genus of bacteria intestinal including Klebsiella spp.، Escherichia coli، Citrobacter and Enterobacter were isolated from effluent samples above and were determined the minimum inhibitory concentration (MIC) against the concentration of various heavy metals such as cadmium chloride، nickel sulfate، mercuric chloride، potassium chromate and potassium tellurite using the agar dilution method، and were reported their resistance against some antibiotics by disk method. In this study، for first time، high MIC، 22mM (4032μg/ml) than cadmium، 20mM (3884μg/ml) than chromium، 20mM (6157 μg / ml) than telluride، 10mM (2628μg/ml) than nickel and 1mM (271. 5μg/ml) than mercury، were reported for Klebsiella spp. bacteria

Environmental pollution by heavy metals has become one of the most serious environmental issues today. In past years، various physical and chemical methods were evaluated and tested to remove heavy metals، but most of them happen to be tough or hazardous، complex، incomplete، expensive moreover requiring lot of energy. Using microorganisms as adsorbents for removal of heavy metal offers a potential alternative to mentioned methods. In this study، three standard yeast including Saccharomyces cerevisiae PTCC 5052، Kluyveromyces marxianus DSMZ5422 Yarrowia lipolytica DSMZ 8218، was used. Resistance of yeast to different concentrations of copper and lead were measured، The yeast were more resistant towards copper (up to 6mM by Y. lipolytica، 5mM by K. marxianus and 1mM by S. cerevisiae) and less resistant towards lead (up to 2mM by the used yeasts). Then based on the observed resistance of the yeast، their ability in metal absorption was examined. Yeast metal uptake at concentrations that they were sensitive، were more. The maximum uptake by the yeasts were 168mg/ g dry weight (g dry W) copper and 54. 6mg/g dry W lead by S. cerevisiae، 75. 56mg/g dry W from copper and 67. 46mg/g dry W from lead by K. marxianus، and 696mg/g dry W copper and 69. 66mg/g dry W from lead by Y. lipolytica. Another test was performed to investigate the effect of glucose on uptake in low concentrations. It was observed that glucose was ineffective on absorption which is energy-independent and effective on bioaccumulation which is energy-dependant.

Human immune system has different cells and molecules interconnected withvarious other body systems. Increasing amounts of released data in postgenomic era makes the analysis of this system more complicated. Therefor the necessity of using computational approaches for data processing and interpretation is more tangible. Immunoinformatics as a subdevision of bioinformatics is a new approach with variety of tools and databases that facilitate analysis of enormous amount of immunologic data obtain from experimental researches. This field could help researchers in new thesis design which was not feasible with conventional methods due to the complexity of data and could provide new insights for exprement selection. Considering these features immunoinformatics appears to be a new field capable of accelerating immunological research progress by circumventing conventional timeconsuming methods. In this study we discuss various tools and databases relevent in the field of immunoinformatics and we also provide insight for immunoinformatics applications and future horizons.

In this study، an antibacterial and antifungal peptide named; Snakin-Z was identified and purified from the fruit of Zizyphus jujuba، using gel filtration and reverse-phase high-performance liquid chromatography (RP-HPLC). This peptide is composed of 31 amino acids with the sequence of: CARLNCVPKGTSGNTETCPCYASLHSCRKYG. The molecular weight of this peptide was found to be 3308. 823 Da. By multiple sequence alignment، Snakin-Z was seen to have highest similarity to antimicrobial peptide (AMP) Snakin-2، but this peptide shows no sequence homology to any AMP in the peptide database. Studies have shown that Snakin-Z has potent antimicrobial activity both against Gram-positive and Gram-negative bacteria as well as fungi. Minimum inhibition concentration (MIC) value of this peptide is suitable for potent antimicrobial peptides. Significant antifungal activity of Snakin-Z was seen to have a greatest effect on Phomopsis azadirachtae with the MIC value of 7. 65 µg/ml; While، among bacterial strains، Staphylococcous aureus was investigated to be the most resistant one with the MIC of 28. 8 µg/ml. Human red blood cells showed good tolerance while exposed to the Snakin-Z. Regarding its antimicrobial activities and its effect against various pathogens and no hemolytic activity، we believe that Snakin-Z is appropriate candidate for the therapeutic applications in the future.

In vitro embryo production (IVEP) has been used for both research and production purposes in cattle. Through analysis of IVEP، detailed mechanisms involved in natural embryo production can be revealed and further the embryo transfer techniques and transgenesis can be facilitated. Although Gonadotropin-Releasing Hormone effects in regulating and controlling the animal reproduction in clinical studies have been well-documented، studies considering the effects of topical process، folliculogenesis، oocyte maturation، fertilization and embryo development are almost lacking. In this study، The effects of different concentrations of Gonadotropin-Releasing Hormone on the process of fertilization and embryo development was evaluated. Collected oocytes (1091 cells) placed in in vitro fertilization media and in vitro culture media، supplemented by 0. 8، 1 and 1. 5 µg/ml of GnRH. Based on microscopic analysis، The cleavage rate and blastocyst rate increased in the in vitro fertilization media and in vitro culture media containing of Gonadotropin-Releasing Hormone but this increased was not statistically. Moreover، by incorporating of GnRH to in vitro culture media، the number of trophectoderm and total cells were increased (p<0. 05).

Dendrosomes are a family of rather new polymers that enhance solubility of insoluble or low soluble drugs in biological media. Curcumin is anti-cancer component by very low solubility in water that in this research transferred with dendrosome as a carrier to human Caucasian gastric adenocarcinoma cell line (AGS). In the present study، we transferred dendrosome formulation of curcumin to AGS cells. Then، apoptosis induction was investigated by propidium iodide staining. Also، transcript level of Survivin and hTERT genes was determined by semi-quantitative RT-PCR. Dendrosomal curcumin increased apoptosis induction in AGS cells in compared to free curcumin. Also، Semi-Q RT-PCR results exhibited the relative decrease of hTERT and survivin gene expression، which involved in cell proliferation and survival increasing. In this study was showed that dendrosomal curcumin induced apoptosis more than free curcumin in AGS cells. Therefore، dendrosome is a sufficient carrier for curcumin delivery to cells and this nanoparticle can be used for treatment and extinguish of cancer cells.

JmjC-domain-containing histone demethylase 2A (JHDM2A) is essential for spermatogenesis and is a key epigenetic regulator expressed in the testis. It specifically demethylates mono- and di-methylated histone H3 lysine 9. JHDM2A directly or indirectly bound to the core promoter regions of transition nuclear protein and protamine genes، the products of which are required for packaging and condensation of sperm chromatin. In this work، 150 infertile men were studied. these men have been proved to be either oligospermia or azoospermia. 91% similarity was observed between jhdm2a gene in human and mouse as shown by bioinformatic analysis using clustal software. exon 13 nad 23 were selected and amplified for mutation screening. The PCR products were used in polyacrylamid gel electrophoresis for further SSCP analysis. Screening of exon 23 did not reveal any variation in subjects screened. Different SSCP patterns were observed among two infertile men، in comparison with others (controls and infertile men). A single nucleotide substitution C33838→A in exon 13 that causes prolin→glutamin exchange revealed by sequencing analysis in these three infertile patients. So by further mutation screening on this gene، it may be considered as a new gene marker for men''s infertility.

Burdock (Arctium lappa L.) is an important medicinal plant containing arctiin and arctigenin، which are important secondary metabolits used as anticancer reagents. Due to the existence of important secondary metabolites in this plant، development of a reliable in vitro tissue culture and regeneration methods to facilitate genetic transformation in this plant is important. In the current study، for optimization of the callus induction، leaf، petiole and root explants of A. lappa were cultured in solid MS medium، which was supplemented with 0. 5% PVP (as an anti-oxidant) and different concentrations and combinations of BA and 2،4-D hormones. This study revealed that the petiole explants induced highest callus rate comparing to the other tested explants. In addition، two hormones combined concentrations of 0. 5 mg/L BA + 1. 0 mg/L 2،4-D and 1. 0 mg/L BA + 2. 0 mg/L 2،4-D، produced the highest amount of callus and were the most suitable treatments for the callus induction.

ISSR markers were used to identify informative markers associated with traits plant high، chlorophyll content، total wet weight، total dry weight، leaf wet weight، leaf dry weight، stem wet weight، stem dry weight، number of leaves، number of stems and their ratio، ratio of leaf dry weight to stem dry weight and total dry weight to total wet weight in alfalfa populations. Sixteen ISSR primers amplified 117 loci among 80 alfalfa genotypes، with an average of 7. 3 loci per primer. Polymorphic information content (PIC) ranged from 0. 65 (UBC849) to 0. 93 (443)، with an average of 0. 77. Stepwise regression analysis between molecular data as independent variables، and morphological data as dependent variables was performed to identify informative markers associated with the studied traits. ISSR loci associated with total dry weight and leaf dry weight were the same. ISSR markers، Kourd and UBC849، were associated with number of leaves and leaf dry weight to stem dry weight، respectively. The maximum variation of chlorophyll content (82%) was accounted by UBC808، UBC812، UBC849، A12، 848، 425 and 456 markers while UBC808 and 425 markers accounted for 15% of the variation of the leaf wet weight. Since most of the used ISSR primers showed significant association with the studied traits، therefore، it is possible to use these markers along with morphological traits in alfalfa breeding programs for identification of suitable parents to produce mapping populations and hybrid varieties.

Citrus take over important roles in economy for every country and Iran is no exception to this rule is where the economic self-sufficiency in agriculture is the reason that the incidence of pests as possible to prevent. We have to do drastic an actions in order to their control. There are a variety of bacterial and fungal diseases that can have devastating effects on agriculture، especially citrus. Control of bacterial infections، is only by pesticides and antibiotics and through the cross section is possible. Use of antimicrobial compounds for the control of these diseases can be very useful. Enterobacter sp. DGH3 is a native bacterium which isolate from south west of Iran، can destroy the cause bacterial canker disease in citrus. It is hope that، controlling this disease with optimization of its medium and production of antimicrobial component by foregoing bacteria.

Mucins are high molecular weight glycoproteins that form a major component of mucus gel layer and protect the underlying epithelium in the gastrointestinal tract versus acid، pathogen and etc. Regarding to high and specific expression of Muc6 gene in gastric and duodenum، deregulated expression of it in peptic ulcer disease and role of promoter polymorphisms in gene expression، in this study، was investigated association of Muc6 gene promoter polymorphisms with risk of peptic ulcer disease by using PCR and sequencing، for the first time. Results indicated that frequency of T allele in -317 position of muc6 gene promoter increased significantly in patients in compared to controls (χ2= 8. 94، df=1، P < 0/005). In the dominant effect of the T allele (comparison between TT+TG vs. GG)، TT+TG genotypes significantly increased 3-fold the risk of peptic ulcer (OR=3. 3، 95% CI= 1. 28-8. 6، P=0. 01). T allele in this position may be decrease expression of Muc6 gene.

Proline dehydrogenase falvoenzyme (ProDH; EC 1. 5. 99. 8) plays an important role in the biosensors and diagnostic kits for the diagnosis of proline related metabolic disorders. The purpose of this research was to isolate and characterize proline metabolizing enzymes producing microorganisms from Iranian soil samples. Isolation and screening of L-proline degradative enzymes from soil samples was carried out in three steps employing enrichment culture technique، thin layer chromatography (TLC) and enzyme activity assay. The isolate was characterized by biochemical reactions، 16S rRNA gene analysis and 16S-23S rRNA Internal Transcribed Spacer (ITS) sequencing. Kinetic studies were performed and 3-D structure of the enzyme of interest was predicted through bioinformatics methods. Among the 150 soil isolates recovered from 30 samples، only one strain displayed the highest enzyme activity toward L-proline (10 U/ml) than others. The Km and Vmax values were calculated as 0. 12 mM and 0. 11 mM/min. The strain was characterized as a new biotype of Pseudomonas putida using phylogenetic analysis of 16s rRNA and 16S-23S rRNA ITS. The predicted 3-D structure of target enzyme also confirmed the similarity of isolated ProDH to the family of P. putida enzymes. This is the first report concerning the ProDH production by a P. putida bacterium isolated from soil sample.

Bacillus subtilis lipase A is the smallest member of α/β hydrolase family with no interfacial activation property. Bacillus subtilis lipase A has numerous applications as well as other lipases، such as industrial، pharmaceuticals، environmental and food products. There have been presented several reports about the engineering of this enzyme based on the random mutagenesis. Therefore، study of molecular dynamics simulation of the enzyme at different temperatures seems to be necessary to understand its dynamical properties. Understanding of such molecular motions is important to switch from random to rational design of the enzyme. Two flexible loops have been identified based on 15 ns molecular dynamics simulation of the enzyme. The extent of flexibility for the loops was different at three temperatures. On the other hand، two critical loops have been identified to play important role on the functional motions of the enzyme as hinges of the axial motions of the secondary elements around the active site cleft.

To increasing the efficiency of production in livestock industry could use recombinant DNA technology. Recently progress in gene transfer system، genetic modifying of ruminal bacteria with ability of hydrolytic enzyme production has been possible. Resulting this technology reduce of disadvantages of enzyme supplements as well as increase of nutrient flow in rumen. Since transformation in rumen bacteria has low efficiency therefore conjugation could be effective for moving genetic elements. In more previous studies E. coli as a facultative anaerobe bacteria has used because could grow in rumen. The present study، an amylase gene previously clone in pET28a and amplified by polymerase chain reaction then subcloned in shuttle vector pGFK114. 1 following transformed in E. coli DH5α. Conjugation was performed between two E. coli DH5α and TG1 donors containing pGFK114. 1 and pRK231 helper plasmid respectively and one recipient E. coliBL21 DE3 using pattern of digestive system. We have successfully transformed cloned amylase gene to recipient bacteria such rumen environment as reported before.