مجله زیست شناسی ایران
سال بیست و ششم شماره 1 (بهار و تابستان 1392)

The electronic structure of GC and AT stacked dinucleotides، in two different forms of DNA (B and Z) is studied، using density functional theory. B3PW91 basis functional with 6-31G** basis set is applied to investigate molecular orbital distributions and energy levels of stacked dinucleotides in B-DNA and Z-DNA. It is demonstrated that the distribution of molecular orbitals in GC dinucleotide، in B form of DNA، is different from those in Z form. While HOMO in B-DNA is localized on guanine base، in Z-DNA، it is dragged away from the base and spreads over DNA backbone as well. Moreover، the energy levels of orbitals are also different. For AT stacked dinucleotide، it is shown that HOMO in B-DNA is localized on phosphate-sugar backbone whereas in Z-DNA it is localized on thymine base. It is also noted that energy levels of molecular orbitals being localized on DNA backbone، are 0. 8 eV less than that of HOMO energy level، indicating the active participation of phosphate-sugar backbone of B- and Z-DNA in chemical reactions.

Fusarium wilt of melon is one of the most common and widespread disease of this crop in the world and specially Iran. This investigation was carried out to determine genetic variation of Fusarium oxysporum f. sp. melonis in Khorassan Razavi province. For this purpose 52 samples were collected from main melon cultivation region of Khorassan Razavi. After purification and identification of isolates، molecular analysis was performed. From all sampled isolates only 35 based on their geographical origin and pathogenicity for molecular analysis were selected. After DNA extraction، genetic variation based on AFLP markers، on 6. 5%polyacryl amide gel electrophoresis and analysis by NTSYS software was done. Results showed at 63% similarity level، all isolates were placed in 6 AFLP groups A، B، C، D، E، F and two groups with just single member. Cluster analysis also showed there was significant genetic variation among F. oxysporum f. sp. melonis isolates in Khorassan Razavi. On the other hand according to cluster analysis it was determined that there was no specific correlation between geographical regions and AFLP genotypic groups. Also، no identified specific correlation was found between pathogenicity groups and isolated point of plant with AFLP groups.

Canola (Brassica napus L.) an agro-economically important crop in the world، is sensitive to many fungal pathogens including Sclerotinia sclerotiorum، the causal agent of stem rot disease. Glucanase is cell wall degrading enzyme which have been shown to have high antifungal activity against a wide range of phytopathogenic fungi. In the present study bgnI gene from Trichoderma virens was overexpressed under the control of the CaMV 35S constitutive promoter in Brassica napus، R line Hyola 308. Transformation of cotyledonary petioles was achieved via Agrobacterium tumefaciens LBA4404. After infection with Agrobacterium، the explants were transferred to selected regeneration medium. The transformed explants were screened in kanamycin containing media. The explants were excised and rooted using appropriate growth regulator. Putative transgenic lines obtained from independent transformation events transferred to the greenhouse for hardening. The presence of bgnI in putative transgenic lines confirmed by the polymerase chain reaction (PCR) using specific primers and PCR-based RFLP. Also، antifungal activity was detected in crude protein extracts from transgenic canola plants when compared to non-transgenic canola using radial diffusion assay.

In Petunia hybrida، Self-incompatibility is controlled by stylar glycoproteins. These glycoproteins could be able to recognize and reject self-pollen. These proteins have ribonuclease activity. In this study، the activity and isoenzyme pattern of S-RNases in self and cross-pollinated styles of Bravo purple star (self-incompatible) and Bravo cool water mix (self-compatible) were investigated (spectrophotometically and PAGE electrophoresis، respectively). The expression intensity of S-RNase was also studied in self- and cross-pollinated styles. Because of the importance of S allele in self-incompatibility interactions، the S-allele was identified in both cultivars. Self-pollinated styles of Bravo purple star showed the highest activity of RNases. Different isoenzyme pattern of S-RNases was found in the styles of two cultivars. The results showed that S-RNase is expressed in both self- and cross-pollinated styles of both cultivars. But، the highest expression was observed in self-pollinated styles of Bravo purple star (self-incompatible). By the comparison of DNA sequencing of S-RNase in Bravo purple star to other identified S-RNases، it was found 100% identity of this cultivar S allele to S3-RNase in Petunia hybrida sub species inflate،. There was 100% identity between nucleotide sequence of S-RNase in Bravo cool water mix and allele S1-RNase in Petunia hybrida.

Angiogenesis is the formation of new blood vessels from existing ones. New blood vessels provide the cells with metabolic requirements. Angiogenesis plays a pivotal role in many physiological and pathological phenomena. Proteinease especially plasmin is critical in degrading of matrix metalloproteinase releasing and activating different growth factor from it. Angiogenesis initiate by the activation of plasminogen on the cell surface. Our previous finding indicates that an anti human plasminogen monoclonal antibody could inhibit the angiogenesis. According to importance of this antibody، we tried to make the scfv of this antibody. SDS-PAGE and immunobloting analysis and ELISA confirmed the expression and immunological activity of the scFv.

Thermophils are a group of microorganisms that optimally grow at temperatures above 45 °C. Reduced sulfur and warm condition are essential for their life and have been found in both terrestrial and marine environments which are heated by geothermal activities. Thermophils have special enzymes and metabolic characteristics that are used in biotechnology. Since thermophiles live in stressful environments it will be very useful to study their survival mechanisms. In this study cell extract from bacteria (Thermus sp. GH5، that is isolated from Ardabil (North West of Iran)) in normal condition (growth at 75 °C) and cold shock condition (growth at 45 °C) were compared. Up-regulated antioxidant proteins and the proteins involved in detoxification showed the creation of oxidative condition about 8 hour after cold shock on thermophilic bacterium. It is possible to extract and use of these stable proteins as diagnostic indicators or protein markers in physiological condition or use in the industrial applications.

Many investigations have revealed the positive role of ectomycorrhizas on growth and mineral nutrition of plants in recent years. To study the role of ectomycorrhiza on the resistance of Pistachio tree var Fandoghy exposed to excess Mg mycorrhizal plants colonized with Agaricus bisporus were prepared in axenic condition. M & NM plants were treated with different Mg amounts according to a factorial experiment and a CRD design in sterile conical flasks. Growth and mineral contents of shoot and roots and the colonization rates of M plants were measured and compared. The results showed that colonization rate of the roots increased as Mg increased in the nutrient solution. Ca،Mg،P،K،Fe،Na،Mn،Zn،Cu contents in M plants increased but excess Mg caused a decline in Ca،K،Zn and P contents of the plants. The results are discussed in concern with the role of ectomycorrhiza in the nutrition of plants.

The effect of ABA was investigated on chlorophyll، carotenoid، anthocyanin and flavonoid content in leaves of male and female cannabis plants at flowering stage. Plants were sprayed with ABA solutions (1 and 10 mg/l) and distilled water as control. Content of chlorophyll a، b and total decreased in female plants sprayed with 1 and 10 mg/l ABA. Male plants showed a decrease in chlorophyll content only in high ABA levels (10 mg/l). ABA treatment did not affect carotenoid content in male plants but it caused the decrease of carotenoids content in female ones. Anthocyanin content decreased by treatment with 10 mg/l ABA in male plants but in females، anthocyanin content increased with ABA treatment (1 and 10 mg/l). In both of female and male plants، flavonoids A 270 on leaf increased in 1mg/l ABA but flavonoids A 330 on leaf did not change. Flavonoids A 300 increased in 1mg/l ABA in male plants and in 10 mg/l ABA in female ones. The content of Δ9_tetrahydrocannabinol (THC) increased the treated plants with ABA. This study showed that male and female plants of cannabis respond to ABA differently. ABA can increase secondary metabolites such as anthocyanin and flavonoids and decrease primary metabolites such as chlorophyll and carotenoids.

Drought is one of the most important environmental stresses that adversely affect the plant growth and crop production. In this experiment، the effect of osmotic stress on proline and soluble sugars content was investigated in two canola cultivars (Brassica napus L. cv. SLM046 –drought-tolerant and cv. Hyola 308 –drought-sensitive). To establish water deficit، the 12 days old canola seedlings were placed in half strength Hoagland solution containing different levels of PEG 6000 ((0، 5%، 10% and 15% (w/v)) for 24 h. The results indicated that water stress increased proline content in shoots and roots of the studied cultivars; but in stress conditions، amount of proline in SLM046 was higher than that of in Hyola 308. On the other hand، drought increased glucose، mannose and rhamnose content in the both tissues of canola cultivars، but content of these soluble sugars in SLM046 was significantly higher than that of Hyola 308.

In vitro propagation has facilitated rapid and mass multiplication of diseases-free plants and acts as a new tool for modern breeding through genetic manipulation. Three commercial cut rose cultivars (Orange Juice، Roulette and Vendetta) were used and evaluated in this study. Newly established plantlets were transferred to the proliferation media on MS medium supplemented with various concentration of BA (0، 1. 59، 4. 4 µM)، NAA (0، 0. 21، 0. 27، 0. 54 µM)، IBA (0، 0. 14 µM) and GA3 (0، 0. 29 µM). Different iron-chelates، FeEDDHA and FeEDTA were used. Two types of auxins، IAA (0، 5. 7 µM) and IBA (0، 9. 9 µM) were tested for root induction. Genotype influence was obvious on multiplication rate with significant differences in response to plant growth regulators. All cultivars showed maximum multiplications on 1. 59 µM BA and 0. 14 µM IBA combination. A significant difference was apparent between cultivars and their response to different root induction treatments. Iron-chelate type had not significant effect on any shoot proliferation or root induction characteristics except for the means of the new shoots.

Seminal plasma chemical compositions affect quality or ability of sperm fecundity (including ability of motion and infiltration to ovum) in fish. In this study seminal plasma ionic ratio of Caspian roach were investigated in spawning migration places. In the second half of March (migration season) to be caughted 10 males with same age and size. The sperm samples were transformed in ice to Gorgan university central lab. Na+ and K+ ions was measured by flamephotometere، and Ca2+، Mg2 was measured by spectrophotometere. Na+ to K+ ratio at the spawning migration place were significant (P<0. 05). Na+ to Mg2+ ratio، K+ to Ca2+ ratio، K+ to Mg2+ ratio at the spawning migration place were significant (P<0. 01). Na+ to Ca2+ ratio and Ca2+ to Mg2+ ratio at Mahisefid (Rutilus frisii kutum) spawning migration place were not significant (P>0. 05). Also، Na+ to K+ ratio and K+ to Ca2+ ratio in Mahisefid broodstock migrated to Shiroud was more than Gorganroud and Tajan. Na+ to Mg2+ ratio and K+ to Mg2+ ratio in Mahisefid (Rutilus frisii kutum) broodstock migrated to Gorganroud was more than Tajan and Shiroud. In conclusion، the Mahisefid (Rutilus frisii kutum) broodstock migrated to shirood have the better semen quality than the other rivers.

In order to determine the population structure of artemia in the Inche Lake in the Golestan Province sampling was carried out in three regions of the Lake. Northern، middle and south ern parts of the Lake were the sampling locations. 66 specimens were collected from the sampling sites. mtDNA was extracted by phenol-chloroform method. Genetic variation investigated using COI gene segment. COI segment then was amplified with primers. PCR product with 720bp was digested with 10 restriction enzymes namely as: RsaI، MspI، MboI، HinfI، HindIII، HaeIII، Eco471، EcoRI، AluI، TaqI. Three out of 10 Enzymes (HaeIII، RsaI، and AluI) could demonstrate the polymorphism. RFLP analysis shows 9 different haplotypes of the samples. Haplotype variation among the samples collected from the north، middle، and south part of the Lake was 0. 580±0. 0110، 0. 588±0. 114، 0. 571±0. 105 respectively. Nucleotide variation among the samples collected from the north، middle، and south part of the Lake was 0. 024، 0. 025، and 0. 015 respectively with 0. 021±0. 0000111 as average. Also the nucleotide variation between the samples collected from the north، middle، and south part of the Lake was 0. 0233 and the nucleotide differences between populations was 0. 0016. Haplotype frequency (X2) between populations was 23. 75. Monte Carlo analysis with 1000 repeats was X2 =0. 057±0. 007. This indicates that there is no significant difference between haplotypes frequency of the samples. Therefore there is only one population of parthenogenetic artemia in the Inche Lake.

Nocistatin is a 17- amino acid peptide، and a product of the same precursor as Nociceptin/ orphanin FQ (NC). It has been shown that Nocistatin antagonize the effect of NC by interacting with the opioid receptor-like 1 (ORL1) receptors. In this study the effects of intracerebroventricular injection (ICV) of Nocistatin، the endogenous ligand of the NC، on food intake and locomotor activities were evaluated in male broiler-type chickens. The results of this study showed that the ICV injection of different doses of Nocistatin (5، 10 and 20 µg) did not alter food intake. There was not a significant difference among groups in regard to preening and stepping. But، there was a significant increase in the group receiving 10 µg /kg of Nocistatin in wing flapping in comparison to the control group (p<0. 05). In this regard، the chicken’s responses were shown to be different from rat، and species differences might be the cause of different response to this peptide.

The role of trace elements and their importance in biological reaction have been extensively evaluated. In this study the amounts of five trace elements including; iron، zinc، copper، chromium and cobalt in nails of premature (PM) and matured (M) male pupils were measured and compared with BMI index. Forty five male premature pupils (averaged 10 years old) and 49 male matured pupils (averaged 17 years old) were randomly selected and by measuring their weight and height، BMI of each pupil was calculated. After that nail samples of each pupil were collected، washed، dried، weighted and then the amount (%) of iron، zinc، copper، chromium and cobalt measured in ash of nails by atomic absorption spectrometer (AAS) method. The results showed that the number of pupils with low BMI is significantly (P<0. 001) higher in PM pupils than in M pupils. In PM and M boys there were not significant differences in iron، zinc، chromium and cobalt amounts between low BMI and normal BMI، except in the amount of copper which was significantly lower in low BMI boys than normal BMI boys (P<0. 05). Also M pupils have less amounts of iron، copper (P<0. 001) and zinc (P<0. 01) and more chromium (P<0. 05) than PM pupils. In conclusion it seems that، there is a probable correlation between the amount of copper and BMI. Also، from nutritional view، the alterations in the amount of iron، zinc، copper and chromium intake may affect the normal rapid growth during the premature and maturing periods.

Diabetes is a metabolic disorder characterised by hyperglycemia resulting from defects in insulin secretion، insulin action or both. Carthamus tinctorius (Compositae) has been used in Iranian traditional medicine in the treatment of diabetes. In this study the blood glucose lowering effect of hydroalcoholic extract of Carthamus tinctorius petals was investigated in male Wistar rats. In this research 18 male white Wistar rats، with body weights of 180 – 220 g were randomly allocated into three groups with six rats per group: group1، nondiabetic control; group2، diabetic control; group 3، prevention group. In order to induce diabetes، alloxan was administered as a single dose (120 mgkg-1 BW)، intraperitoneally. In 2 and 3 groups to induce diabetes، alloxan was administered as a single dose (120 mgkg-1 BW)، intraperitoneally. At the initial and the end of 2 and 6 weeks of experimental period، rats were fasted for 16h، and then fasting blood samples were collected in tubes with heparin for estimation of blood glucose and others factors levels. Blood was collected from the orbital sinus. The results indicated significant reduction in serum glucose level in the group 3 (P<0. 05). Histological studies of the pancreas of this animals، demonstrated this results. This results showed that the hydroalcoholic extract of Carthamus tinctorius effect on preventive of diabetes. The effect of this extract can be due to the presence of flavonoides and their antioxidant effects.