جستجوی مقالات مرتبط با کلیدواژه « واکنش زنجیره ای پلیمراز » در نشریات گروه « علوم پایه »

In sour cherry, as in other species of the genus Prunus, there is a gametophytic self-incompatibility (GSI) phenomenon. In this research, relations between pollen and pistil of 10 superior sour cherry genotype were investigated by using biological and molecular methods. In biological methods, pollen grains are prepared in balloon stage (D phenological stage) and then after evaluating the growth and percentage of pollen germination in medium, in suitable time flowers were emasculated, open pollination, controlled self and cross pollination were carried out in the orchard. In the molecular method, PCR-based methods were used to identify S alleles. The results showed that the highest pollen germination was observed on the stigma in self-pollination, and regarding of the number of pollen tube at the upper and lower parts of the pistil and ovary, the highest was related to open pollinating. Nine known S-haplotypes (S4, S6, S9, S6m2, S24, S26, S35, S36b and S36a) were identified, that alleles S6/S6m2, S9, S24 have a high frequency. Our study showed the low diversity of S alleles between studied genotypes. According to the growth of pollen tubes in style and ovary in all cases of pollination all of studied genotypes are compatible.

Gram-positive , Bacillus thuringiensis, produces crystals with insecticidal properties. rDNA sequence analysis is used to study the evolution and classification of organisms. The study was conducted on 16SrDNA sequence of five native isolates of Bacillus thuringiensis using the polymerase chain reaction.

Characteristics and phylogenetic relationships between five sequences of native isolates along with other isolates in the genebank and other species of the genus Bacillus were performed with Mesquite and leBIBIQBPP database.

The five native isolates were 92.06 to 99.93% similar to each other and 99.73% to 100% similar to other isolates of Bacillus thuringiensis. Phylogenetic trees showed Bt1019, Bt1020 and Bt1039 in the first group and Bt1001 and Bt1091 in the second group. Based on Bt1001 sequence analysis using leBIBIQBPP, the minimum distance with Bacillus frigoritolerans was obtained. The sequence of Bacillus anthracis was close to Bt 1019. The Bt 1020 sequence was closest to Bacillus cereus. In the case of Bt1039, in addition to Bacillus cereus, the lowest distance was observed with Bacillus marcorinectum. The Bt1091 sequence showed the most similarity with Bacillus frigoritolerans.

Protein crystals were observed in the native bacteria. Toxic crystals are produced only by Bacillus thuringiensis. BLAST program for 16SrDNA gene sequence in the native isolates also showed the most similarity to Bacillus thuringiensis isolates in the genebank. Moreover, the results predicted that the three native isolates including Bt1019, Bt1020 and Bt1039 could be toxic against lepidopteran and two isolates including Bt1001 and Bt1091 could be toxic against coleopteran.

Genetic analysis of fish populations is essential for conserving biodiversity and increasing knowledge about the survival of species, and finding the factors threatening or contributing to the survival of these populations. The present study is aimed at investigating phylogenetic relationship of Yellowtail Scad in the northern Persian Gulf and Oman Sea by sequencing mitochondrial Cytochrome Oxidase I gene. Ninety yellow tail Scad have been collected from Bandar Abbas, Bushehr, and Chabahar port. Genomic DNA was extracted using Ammonium acetate method. After electrophoresis on 1% agarose gel, Cytochrome Oxidase I (COI) gene was amplified by Polymerase Chain Reaction (PCR), using pair of primers. After sequencing of PCR product, the phylogenetic tree was drawn by MEGA7 software with different methods (Maximum Likelihood, Maximum Parsimony, and Bayesian) using (Esox lucius) as an extraspecific group. All samples from Bandar Abbas, Bushehr, and three samples from Chabahar port were located in the same clade. Chabahar sample with a little more distance was located in separate clade and due to high supportive degree (bootstrap) showed sister group relationship. Moreover, these two clades were located with more evolutionary distance from extraspecific group. Consequently, COI gene sequencing was an appropriate and reliable method for phylogenetic relationship of Yellowtail Scad, providing useful information about protection and management of this valuable species.

Genetically modified crops are produced using modern biotechnology to create or increase desirable traits such as increased efficiency or resistance to unfavorable factors. In recent years, Almost 200 million hectares of world crop acreage planted with GM crops including maize, so it is possible that GM maize has been imported to Iran especially as animal feed. Therefore, 25 samples of imported maize used for animal feed were tested to detect probable GM maize. The DNA of samples was extracted by CTAB method and its quality and quantity were evaluated by electrophoresis and spectroscopic methods and their amplifiability confirmed by PCR using the internal maize genomic gene of Zein based on INSO 10763. Detection of GM varieties was performed by the polymerase chain reaction (PCR) method based on INSO 9617 using primers CaMV 35S, NOS terminator, npt II marker gene generally existed in GMOs. According to PCR results with primers specific for sequences common in GM organisms, in 3 samples out of 25 samples a 195 bp band related to CaMV 35S promoter and in 3 feed samples out of 25 samples a 118 bp band related to NOS terminator were observed, 2 of them showed both sequences. The band related to nptII marker gene was observed in none of samples. These results can lead to the probability of existing of GM ingredients in samples. In order to identify that the observed electrophoretic bands are belonged to the GM organisms, some confirmation tests are needed.

Bacterial infections of the genital system are common causes of infertility. One of the most important causes of male infertility is seminal and genital tract infections. In the meantime, a wide range of bacteria, in varying degrees, contribute to infertility in men. Helicobacter pylori may be involve in infertility. Because antibodies against this bacteria have been significantly detected in the genital fluids of infertile patients. The aim of this study was to determine the presence of Helicobacter pylori in the semen of the infertile men with rapid molecular PCR method and determine its percentage.

100 samples of semen collected from Saram hospital and DNA Extracted from these specimens using Boiling/DNG_PLUS method.  Optimized PCR test was performed on samples. PCR test evaluated from the respect sensitivity and specificity.

In this study, amplicon with the size of 294 bp, observed with agarose electrophoresis.  In the specificity test, primers created only a band for H.pylori DNA. Of the 100 samples tested, only 10 samples (10%) were positive for DNA of H.pylori.

According to the results of this study, H.pylori may be one of the bacterial agents that can be considered for male infertility, of course requires further studies. While PCR is suitable, quick and sensitive molecular technique for detection of H.pylori in infertile men.

Warfarin is a commonly-prescribed anticoagulant used to treat and prevent thromboembolic events. The requirement for varying doses of warfarin depends on genetic and environmental components. In this study, the frequency of two single-nucleotide polymorphic variants of the vitamin K epoxide reductase complex subunit 1 (VKORC1) gene (1173 C>T (rs9934438) and 3730 G>A (rs7294)) and its correlation with warfarin maintenance doses were investigated in patients with heart valve replacement from West Azarbayejan, Iran. Blood samples were obtained from 185 patients; their genomic DNA was extracted and samples were genotyped by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay. To assess if the blood warfarin level is different among genotypes, we used a one-way analysis of variance (ANOVA) followed by a Tukey’s post-hoc comparison. The minor allele frequency was determined to be 54% for 1173T and 53.7% for 3730A. Patients who carried the G allele at position 3730 and T allele at position 1173 required a significantly lower daily mean warfarin dosage (P <0.001). Consideration of the VKORC1 gene polymorphism, especially at the initial stages of the therapy, can be helpful in pre-treatment dosing of warfarin, which, in turn, reduces the adverse effects resulting from inappropriate drug prescription.

Identifying the structure and function of alpha-Synuclein protein can lead to the development of appropriate treatments for Parkinson disease. The aim of the current study was to investigate DNA cloning and the expression of alpha-Synuclein protein in E. coli. In this experimental study, the sequence of encoding alpha-Synuclein in pRK172 recombinant plasmid was amplified by Polymerase Chain Reaction (PCR), using best primers. The synthesized DNA was, then, digested by restriction enzymes and cloned into pET28a and recombinant plasmid was transferred into the expression strain of E. coli (BL21) by Calcium Chloride method. The expression of alpha-Synuclein gene was induced by Isopropyl-Beta-D-Thiogalactoside (IPTG) and the expression of alpha-Synuclein was investigated by SDS polyacrylamide gel electrophoresis (SDS-PAGE) method. Sequencing was done, using the ClustalW algorithm by the BioEdit 5.0.9 program. In products of DNA enzymatic digestive reactions and pET28a plasmid with restriction enzymes, the size of the fragments indicated the correctness of the enzymatic reactions. The synthesized DNA and pET28a plasmid were 407 and 5369 nucleotides, respectively. The translation of the sequence of the cloned fragment revealed a 100% similarity to the human alpha-Synuclein protein. In expressing the recombinant protein in comparison with negative control samples, adding IPTG increased the expression of alpha-Synuclein protein in all samples, especially 2 hours after induction. Most of alpha-Synuclein expressed from the pET28a-alpha-Synuclein plasmid accumulated in the bacteria as incorporated objects. The alpha-Synuclein protein is cloned into the pET28a plasmid and formation of the objects incorporated by alpha-Synuclein is confirmed by the expression of the pET28a-alpha-Synuclein system and paves the way for producing this protein in high scale.

Escherichia coli is a common bacterium in the intestinal microflora of warm-blooded animals. They are routinely shed into the environment through feces and can contaminate water and soil, and, consequently fruits and vegetables .Enterohemorrhagic E. coli strains are recently emerged group of food-borne pathogens that are a significant public health threat. This group causes bloody diarrhea and hemolytic uremic syndrome (HUS), and the disease is prevalent in developed countries. The purpose of this study was to isolate and identify the E.coli O157: H7 and other verotoxigenic ones and major virulence genes (rfbE, eaeA, stx1, stx2) in fecal swab samples by PCR in Shahrekord area.
In Spring and Summer 2015, 400 cow fecal swab samples were collected from farms in Shahrekord area. Bacteriological and biochemical examinations were done for detection of E.coli. PCR assay was done for identification of O157:H7 serotype and other verotoxigenic E. coli using rfbE, eae, stx1 and stx2 genes.
E. coli O157:H7 was not detected in any strains tested. But PCR showed that out of 384 E.coli strain, 104(27/08%) isolates carried stx1 gene, 36(9/37%) carried stx2 gene and 16 (4.16%) carried both stx1 and stx2 genes. Intimin (eaeA) gene was detected in 280(72/91%) of the isolates. Among verotoxigenic strain antibiotic resistance to Tetracycline 87/1%, Ampiciline 51/62%, Cefotaxime 48/38%, Gentamycin 25/81%,, Ciprofeloxacin 3/22% and Sulfamethoxazol 3/22% were observed.
Discussion and According to the results, although the serotype O157: H7 did not isolate from the feces of cattle but other verotoxigenic strains that showed high resistance to antibiotic were isolated so it is a risk for human health.

Aim and White spot syndrome virus (WSSV) infection has resulted in severe production and economic losses in shrimp culture globally. The first time the white spot disease (WSD) was reported in Iran was in 2004 and 2008, respectively in Bushehr Province. In Sistan and Balochestan province only the WSD was reported in 2008. White spot syndrome virus (WSSV) is the most pathogenic among the penaeid shrimp viruses. WSSV DNA samples for PCR test were prepared from diseased shrimp. Specific PCR primers were used for the amplification of VP28 gene in WSSV. VP28 gene of DNA isolate of WSSV was amplified by PCR and the PCR product was sequenced. The results were submitted to GenBank (KF723558). The nucleotide sequence (KF723558) was compared with the VP28 gene sequences in the GenBank database (NCBI). 36 sequences showed significant alignments with 99% homology which include the sequences from Korea, Japan, US, Indonesia, China, Vietnam, Taiwan, the Netherlands and Thailand. However, the homology was not observed 100% in the sequences.

Genetic polymorphism of milk proteins has been associated with composition, manufacture, and traits of milk. Caseins are the most important milk proteins that its genes are strongly linked and inherited together. κ-casein, which is a quantitatively minor constituent of bovine milk, is thought to play a critical role in organization, fixation and aggregation of casein micelles and firmness of curd during cheese making. In this study, we aimed to investigate the polymorphism of κ-casein gene in Iranian Holstein cows. In this study, κ-casein gene polymorphism among 50 DNA samples of Iranian Holstein cows via polymerase chain reaction sequence analysis (PCR sequencing) was analyzed. For data analysis SPSS 11.5 (ANOVA test) was used. Four polymorphic sites that created four variants and seven different genotypes of κ-casein gene were identified. In this population the frequencies of A, B, C, and E alleles were as 0.391, 0.413, 0.087, and 0.109 respectively. We suggest that the frequency of κ-casein gene B allele should be increased in Iranian Holsteins because it is an essential factor in marker-assisted selection for milk traits.

Polycyclic aromatic hydrocarbons (PAHs) were extensively spread in the environment and are regarded as one of the mutagenic and carcinogenic agents on living creatures. Among the vast variety of procedures for the elimination of contamination, biological removal is capable of transmuting pollutants into innocuous and nontoxic substances using less amount of energy, chemicals and time. The study was aimed at evaluating the possibility of growth of the indigenous bacteria isolated from oil-polluted soils, in the presence of PAH compounds in the laboratory, and also identifying them by using the method of PCR. Specimens of the research were isolated from environmental gasoline and oil-polluted soils from the Isfahan City refinery. Initially, the native bacteria were separated from the contaminated soil with such compounds by utilizing a basic medium containing the concentration of 12.8 mg/l in 16 PAH compounds. Then, those bacteria which were able to grow and reproduce in the presence of the compounds identified through biochemical experiments and determination of genome sequence and consequently registered as new species. The results obtained in the study substantiated that approximately 13.3% of the total heterotrophic bacteria possess a degradable ability of the hydrocarbons. After the evaluation of biochemical tests and gene sequencing, it was disclosed that the isolated indigenous bacteria belonged to Bacillus licheniformis ATHE9, Bacillus mojavensis ATHE13 and a particular species of Bacillus (ATHE10). The results of the present research verify the importance and proficiency of the native bacteria in the terms of the elimination of PAHs pollutions in contaminated areas.

Today hydrocarbon pollution is the most important environmental problem. Biological methods can play an important role in removing these contaminants to the environment. This study was aimed to isolate aliphatic compounds degrading bacteria and identify the best degrading strain. Sampling of waste oil depot took in the city of Kerman, Tehran and hydrocarbon-contaminated soils. Alkane degrading bacteria were isolated by using enrichment Bushnel-Hass medium containing hexadecane (as source carbon). In order to identify superior strains, a part of 16SrDNA gene was amplified by PCR and then sequenced. Also, the presence of alkane’s hydroxylase gene in these strains was confirmed by using specific primers. A total of fifteen alakne degrading bacteria were isolated which 8 strains were selected as superior strains. These strains belonged to the genus of Rhodococcus jostii,Stenotrophomonas maltophilia strain M2, Achromobacter piechaudii, Tsukamurell atyrosinosolvens, Pseudomonas fluorescens, Rhodococcus erythropolis,Stenotrophomonas maltophilia strain Q1, Pseudomonas aeruginosa. In this study, the highest growth rate of strians was in concentrations 2.5 percent of hexadecane and the lowest was found in 7 percent. Also, all of the strains have alkane hydroxylase gene. Our results indicated that threre is a high diversity of degradative bacteria in Iran ecosystem and their ability to degrade petroleum wastewater. So, with a proper management of these bacteria can be used to minimize pollution caused by waste oil industries.