فهرست مطالب

Iranian Journal of Biotechnology
Volume:2 Issue: 4, Autumn 2004

  • تاریخ انتشار: 1383/11/11
  • تعداد عناوین: 8
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  • Sadeq Vallian Pages 220-229
    The PML gene was first identified at the breakpoint region of t(15;17) chromosomal translocation in acute promyelocytic leukemia (APL). There has been a large attention toward the elucidation of the biological function of PML in the cell. Our studies and those of others during the last decade resulted in elucidation of several fundamental biological functions for PML. These include: i) Regulation of transcription in a promoter dependent manner; ii) Suppression of growth and tumorigenisity of cells transformed by oncogenes; iii) Involvement in cell cycle progression through interaction with several key proteins involved in cell cycle regulation and apoptosis, e.g. p53 and pRb; iv) Association and mediation of the effects of a number of viral regulatory protein via localization in the nucleus. These findings have introduced not only PML as a multifunction protein, but also opened new windows for analysis of mechanisms involved in leukemogenesis of the APL disease. The present article focused on the studies involving the elucidation of different biological properties of PML
  • Mohammad Ebrahimi, Svetlana Vladimirovana Podolskaya, Natalia Grigorieva Gorovenko Pages 230-235
    Asthma is a chronic inflammatory disease, which involves a variety of different mediators, including reactive oxygen species (ROS). Previous studies have suggested that glutathione S-transferase (GST) genotypes may play a role in determining susceptibility to bronchial asthma (BA), though the data are often conflicting. In this study we investigated GSTT1 and GSTM1 status in relation to BA in asthmatic patients in Ukraine. To evaluate the role of GSTT1 and GSTM1 genotypes in susceptibility to BA, we conducted a case-control study of 95 cases of asthmatic patients and 253 population-based controls in Kiev city, Ukraine. All patients and control group were interviewed for information on lifestyle risk factors and DNA extracted from blood samples was used for genotyping. GSTT1 and GSTM1 genotypes were identified by multiplex polymerases chain reaction. The frequencies for the GSTT1 null genotypes were 26.31% and 14.12%, and for the GSTM1 null genotypes 41.50% and 50.59% among cases and controls, respectively. The GSTT1 null genotype was associated with an increased Chi-square for BA (c =6.12, P=0.013), but no relationship between BA and the GSTM1 null genotype was observed. Its possibility that genetic polymorphism in detoxifying enzymes may have a role in individuals susceptibility to BA.
  • Elmira Mohandesan, Seyed Javad Mowla, Alireza Hojabri Noobari, Mohammad Mehdi Yaghoobi, Seyed Alireza Mesbah, Namin Pages 236-242
    Extraction and analysis of DNA from ancient remains has numerous applications in archeology and molecular evolution. However, it has become obvious that ancient DNA (aDNA) can be easily contaminated with modern DNA, so it is crucial to detect contamination and to distinguish contaminant from authentic results. In the present study, we report the successful extraction and amplification of aDNA from 3000-3500 year-old human remains excavated from Masjede kabood (Tabriz, North-West of Iran) burial site. To test the authenticity of the extracted aDNA, we have developed a nested PCR/restriction enzyme digestion method for molecular sex determination of the skeletal remains, which their gender was known based on their morphology and belongings (Crown, Sword, Bracelet etc.). A simple and effective modified ethanol precipitation-based protocol was used for DNA extraction from 35 human skeletal remains. A segment of Homologous Amelogenin Gene (AMG), which has different alleles on X and Y-chromosomes, was amplified and analyzed. The obtained data were compared with anthropometric reports as a control for the rate of precision in aDNA analysis. The results showed that reliable aDNA can be extracted and amplified from archeological remains. The presented sex determination procedure could also be used as a reliable control for testing the authenticity of aDNA results..
  • Mansour Mashreghi, James I. Prosser Pages 243-249
    Construction of a luminescent microbial biosensor as a sensitive and rapid biotechnological tool for monitoring survival and activity of genetically engineered microorganisms (GEMs) in the contaminated environment has been the main focus of this study. Four rifampicin resistant phenanthrene-degrading bacteria viz., Commamonas testosteroni GZ38A, C. testosteroni GZ39, Pseudomonas putida GZ44 and P. stutzeri P16 were made using gradient plate techniques. All resistant strains were transformed with the plasmid harboring the mini-Tn5-tet transposon cassette, containing the luxAB genes to confer stability. C. testosteroni GZ38A and P. stutzeri P16 were successfully lux-marked in this manner. It was found that lux-marked strains of C. testosteroni GZ38A were not able to degrade phenanthrene. Although the maximum growth rate of lux-marked strain was significantly lower (P < 0.05) than that of the wild type P. stutzeri P16, the P. stutzeri P16-luxAB4 was selected because it has the following criteria: the stability of expression of tet- resistance over 180 generations, phenanthrene -degradability and high level of luminescence light output in the absence and presence of phenanthrene. The addition of 1 litter (0.5 % v/v) n-decyl aldehyde produced consistently high levels of luminescence at various stages of selected strain. Results clearly indicated that lux-marked strain was appropriately constructed and it is a novel biodegradative luminescent biosensor which enables us to monitor the fate of a phenathrene bacterial degrader genetically or non-genetically made within a polluted environment.
  • Fahimeh Ghasemi, Alireza Zomorodipour, Sharareh Shojai, Fariba Ataei, Mahvash Khodabandeh, Mohammad Hossein Sanati Pages 250-260
    Periplasmic expression of human growth hormone (hGH) in an arabinose-regulated Escherichia coli system was studied, using two forms of gIII signal sequence differing from each other at position 17 (carrying either His17 or Arg17 at position -2 in the hGH precursor). The expression of hGH by the two recombinant plasmids was studied in the Top10 strain of E. coli. Results obtained from the expression analysis showed that the hGH expression in both of the recombinant bacteria are tightly regulated with arabinose. An optimal expression was found to occur in the medium containing 1.33 mM L-arabinose at 37C. However, periplasmic expression of hGH occurs when the native signal sequence (His17-gIII) is applied. In the case of the bacteria carrying plasmid with the Arg17-gIII signal peptide, although the expression level was high, no mature protein could be detected under conditions tested. These data suggest for a probable effect of the -2 position in processing of the preprotein (gIII::hGH). Optimized growth and inducing conditions of the selected clone were investigated and application of a suitable signal peptide cleavage site for more efficient periplasmic production of hGH is discussed. The two recombinant plasmids presented in this work, have provided tools to study an aspect of amino acid sequence in the cleavage region on the processing and secretion of hGH.
  • Mohsen Nosrati, Seyed Abbas Shojaosadati, Trichur Ramaswamy Sreekrishnan, Satya Narayan Mukhopadhyay Pages 261-268
    Different initial concentrations of slurry waste food (discarded food), with and without the overlying layer of fat derived from the waste were anaerobically digested at 55C. At solids concentrations less than 20 g/l no significant difference was observed in terms of volatile fatty acids and methane production between samples containing fat layer and samples without it. However, at higher concentrations, differences became more obvious. Biogas released from a 50 g/l fat excluded sample was around 100% more than the gas generated from the fat included sample with the same initial solids concentration. Inhibition by propionate was not significant in concentrations less than 2000 mg/l. In the absence of fats, the inhibition caused by accumulation of propionate could be overcome partially by the methanogenic bacteria. Based on the energy generated in the form of methane, it was found that thermophilic anaerobic digestion of waste food could be an autothermal process for fat excluded feeds.
  • Raheem Haddad, Vicky Buchanan, Wollaston Pages 269-278
    Leaf senescence is the sequence of events leading to cellular disassembly and mobilization of released materials that cause accumulation of reactive oxygen species. DNA sequencing of one of senescence-isolated cDNA, LSC650, showed a high level of similarity with a catalase gene of Arabidopsis. Transcript level of this isoform was highly increased during senescence. The enzyme activity of catalase was also assayed during different developmental stages in Brassica napus and showed a high level of activity during last part of leaf senescence. Both kinetic assay and northern analysis exhibit that catalase has the potential to play a significant role in the cell defense against produced hydrogen peroxide as part of the macromolecules breakdown. Gene expression pattern was characterized by mRNA hybridization with several antioxidant cDNA clones. Transcript levels of discussed genes were markedly increased during senescence stages. We conclude that the major part of the mRNA changes observed during senescence stages of leaves is connected with leaf senescence, whereas free radical-related transcripts appear to protect cells from oxidative damage.
  • Saeed Rauf, Hafeez, Ur Rahman, Tariq Manzoor Khan Pages 279-282
    Multiple shoot induction was studied in upland cotton cv. NIAB-999. Cotyledonary nodes obtained from aseptically raised seedling were cultured on modified Murashige and Skoog medium (MS) supplemented with different doses of Kinetin. Cotyledonary nodes produced maximum number of shoots (3.43 shoots/ explant) when cultured on MS medium supplemented with 0.25 mgl-1 Kinetin. Highest percentage (93.3 %) of root development and root length (5.85 cm) was obtained when shoots were cultured on MS medium supplemented with 0.5 mgl-1 napthalene acetic acid (NAA) and 0.1 mgl-1 Kinetin.