Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
Browse
5 results
Search Results
Article Citation - WoS: 7Citation - Scopus: 8Identification of Extracellular Enzyme Producing Alkalophilic Bacilli From Izmir Province by 16s-Its Rdna Rflp(John Wiley and Sons Inc., 2004) Akbalık, Güney; Güneş, Hatice; Güneş, Hatice; Yaşa, İhsan; Harsa, Hayriye Şebnem; Yavuz, Elif; Yenidünya, Ali Fazıl; Yenidünya, Ali Fazıl; Harsa, Hayriye Şebnem; 04.03. Department of Molecular Biology and Genetics; 01. Izmir Institute of Technology; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 04. Faculty of ScienceAims: To screen industrially important extracellular enzymes from the newly isolated alkalophilic bacilli and to characterize them by phenotypic and 16S-internal transcribed spacer (ITS) rDNA restriction pattern analysis. Methods and Results: Three different environmental samples, soil, leather and horse faeces, were collected within the province of Izmir. Isolates grown on Horikoshi-I medium for 24 h at 37°C were screened for extracellular enzyme activity by using eight different substrates: birchwood xylan, carboxymethylcellulose, casein, citrus pectin, polygalacturonic acid, soluble starch, and Tween 20 and 80. In total, 115 extracellular enzyme-producing bacilli were obtained. Casein was hydrolysed by 78%, soluble starch by 67%, citrus pectin by 63%, polygalacturonic acid by 62%, Tween 20 by 34%, birchwood xylan by 16%, Tween 80 by 12%, and carboxymethylcellulose by 3% of the isolates. The isolates were differentiated into 19 distinct homology groups by the 16S-ITS rDNA restriction pattern analysis. Conclusions: Eight different extracellular enzyme activities were determined in 115 endospore forming bacilli. The largest 16S-ITS rDNA homology group (HT1) included 36% of the isolates, 98% of which degraded casein, polygalacturonic acid, pectin and starch. Significance and Impact of the Study: This study is the first report on the characterization of the industrial enzyme-producing alkalophilic bacilli by 16S-ITS rDNA restriction fragment length polymorphism (RFLP). Restriction profiles of 64% of the isolates were found to be different from those of five reference strains used.Article Citation - WoS: 24Citation - Scopus: 25Identification of Extracellular Enzyme Producing Thermophilic Bacilli From Balcova (agamemnon) Geothermal Site by Its Rdna Rflp(John Wiley and Sons Inc., 2004) Yavuz, Elif; Güneş, Hatice; Yenidünya, Ali Fazıl; Yenidünya, Ali Fazıl; Güneş, Hatice; Yavuz, Elif; Harsa, Hayriye Şebnem; 04.03. Department of Molecular Biology and Genetics; 01. Izmir Institute of Technology; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 04. Faculty of ScienceAims: Molecular characterization of extracellular enzyme producing thermophilic bacilli from Balcova geothermal site. Methods and Results: Three types of geothermal samples were collected: mud, re-injection water, and samples from uncontrolled hydrothermal vents. Isolates grown at 55°C in culture media prepared in sterilized re-injection water, were screened for extracellular enzyme activity by using eight different substrates: casein, carboxymethyl-cellulose, pectin, polygalacturonic acid (PGA), soluble starch, Tween 20 and 80, and xylan. In total, 109 thermoaerophilic isolates were selected. All of the isolates could hydrolyse Tween 20 (100%) but not Tween 80. Soluble starch was hydrolysed by 96%, casein by 55%, xylan and carboxymethylcellulose by 9%, and pectin and PGA by 2% of the isolates. The isolates were grouped into 14 different homology groups by the restriction pattern analysis of 16S-internal transcribed spacer (ITS) rDNA RFLP. Each of the RFLP groups was also studied by 16S rRNA gene partial sequence analysis. Plasmid DNA profiles revealed that 15 of the isolated strains contained small plasmid DNA molecules ranging in size from 12 000 to 35 000 bp. Conclusions: Combined analysis of 16S-ITS rDNA RFLP and 16S rRNA gene partial sequence results indicated the presence of novel or existing species of Anoxybacillus (nine species) and Geobacillus (three species). Significance and Impact of the Study: In this study 16S-ITS rDNA RFLP was applied for the first time to differentiate thermophilic bacilli. It was also the first study on thermophilic bacilli of Balcova geothermal site.Article Citation - WoS: 1Citation - Scopus: 1Identification of Differentially Expressed Genes in Isogenic Highly Metastatic and Poorly Metastatic Cell Lines of R3230ac Rat Mammary Adenocarcinoma(John Wiley and Sons Inc., 2003) Güneş, Hatice; Güneş, Hatice; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyTumour metastasis occurs as a result of a cascade of events including alterations in the expression of various genes. The identification of such genes is essential to understanding formation of metastasis. In a previous study, highly metastatic (LN4.D6) and poorly metastatic (CAb.D5) cell lines were obtained from the rat mammary adenocarcinoma cell line R3230AC. Subtractive hybridization was used to identify differentially expressed genes between these two cell lines. We identified eight cDNA clones in CAb.D5 and six cDNA clones in LN4.D6 that were differentially expressed. One of the cDNA clones in each cell line had no homology with known sequences. Expression patterns of these differentially expressed genes were examined in a pair of rat mammary and prostate adenocarcinoma cell lines. Compared with cell lines examined, cDNA FF-10 was only expressed in CAb.D5; however, cDNA RB-8, RE-1, RF-5 were only expressed in the highly metastatic LN4.D6. No correlation was observed between expression patterns of the differentially expressed genes and metastatic potential of these cells. However, differential expression of genes, especially cytokeratins (CK8 and CK5) and collagens (III and IV) between highly metastatic and low metastatic rat mammary adenocarcinoma cell lines might initiate further investigation of these genes in metastatic process.Article Citation - WoS: 5Citation - Scopus: 4Prolactin Receptor Expression by Splenocytes From Rats in Various Hormonal States(John Wiley and Sons Inc., 1997) Güneş, Hatice; Güneş, Hatice; Mastro, Andrea M.; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyProlactin (PRL) is mitogenic for lymphocytes in vitro, but the responsiveness of lymphocytes depends on the in vivo hormonal status of the rats from which the cells were obtained. Lymphocytes from ovariectomized (OVX) rats, but not from rats in oestrus or from male rats, respond to prolactin; administration of oestradiol to OVX rats diminishes the response. In order to determine if a correlation exists between lymphocyte responsiveness to prolactin and levels of cell surface prolactin receptors (PRL-R) expression, the percentage of splenocytes and each splenocyte subpopulation expressing surface PRL-R from rats of various hormonal states (OVX, oestradiol-injected OVX, oestrus and male) was analysed by single-colour and dual-colour flow cytometric analysis. We found that approximately 20% of splenocytes expressed surface PRL-R regardless of hormonal states (n = 16). The majority (85%) of PRL-R positive splenocytes were B lymphocytes whereas 11.1% and 4.8% of splenocytes expressing the PRL-R were CD4 positive T-helper (TH) and CD8 positive T-cytotoxic (TC) lymphocytes, respectively. B lymphocytes also stained more brightly than T lymphocytes. This distribution of PRL-R expression did not show significant alterations on total splenocytes or TH and TC lymphocytes during various hormonal stages. However, the percentage of PRL-R-positive B lymphocytes increased markedly in OVX rats (twofold), compared to rats at oestrus. In summary, no correlation was found between the responsiveness to prolactin as a mitogen and levels of PRL-R expression by lymphocytes from rats at different hormonal states. This result suggests that sex steroid hormones may control prolactin responsiveness of lymphocytes by affecting the signal transduction pathway through PRL-R rather than by altering the level of the cell surface receptor expression.Article Citation - WoS: 15Citation - Scopus: 14Prolactin Receptor Gene Expression in Rat Splenocytes and Thymocytes During Oestrous Cycle, Pregnancy and Lactation(John Wiley and Sons Inc., 1997) Güneş, Hatice; Güneş, Hatice; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyMuch evidence suggests that prolactin (PRL) has an immunoregulatory function. Part of this evidence is that the receptors for PRL are present on lymphocytes. Probably the effects of PRL on cells of the immune system depend on the level and specific forms of PRL-R present on the target cells. Therefore, PRL-R expression at both protein and mRNA levels was examined during oestrous cycle, pregnancy and lactation using Western blotting and PCR analysis. Antibody to the long form of PRL-R detected 84 and 42 kDa protein bands in the spleen but only 84 kDa band in the thymus. The expression pattern of these two protein bands was different in the spleen, suggesting that these two isoforms of PRL-R long form are differentially regulated by the hormones of oestrous cycle. In addition, depending on the tissue, the level of mRNA for the short and long forms of PRL-R showed a significant change at different stages of oestrous cycle. Moreover, 42 and 84 kDa PRL-R bands were detected in both spleen and thymus throughout the pregnancy and lactation; however, the expression pattern of 84 kDa protein band was different between tissues. This finding suggests that each tissue exhibits differential response to hormones which affect PRL-R content.