IRANIAN JOURNAL OF BIOLOGY
Year:2011 | Volume:24 | Issue:5|Papers Count:19

Tissue plasminogen activator (tPA) protein was found as superior thrombolytic agent for treatment of diseases such as acute myocardial infarction and efforts is currently focused to improve the tPA molecule and thereby it's pharmacokinetic properties.Reteplase (K2S) is a derivative tPA that has a longer half-life and greater resistance to inhibitor than the natural tPA molecule. The aim of this research is cloning and expression of K2S form of the tPA cDNA in eukaryotic systemL. tarentolae which is recently has been introduced as a suitable host for expression eukaryotic genes. K2S form of tPA cDNA amplified by PCR and has cloned at ssurRNA (18s) site of L. tarentolaegenome by homologous recombination. Diagnostic PCR analysis showed integration of K2S expression cassette in 18srRNA gene. Performance of zymography analysis on culture supernatant of transfected L. tarentolae showed serine protease activity of the rK2S protein produced and demonstrate that rK2S protein produced in L. tarentolaecells was biologically active. Hence, L. tarentolae is the first useful biotechnologically eukaryotic organism and simple nutrient requirements; we hope to reduce the production cost of this protein by cloning of K2S gene in this system.

Lipase (Triacylglycerol acylhydrolases, EC 3.1.1.3) hydrolyzes triacylglycerol to glycerol and fatty acids in the water and fatty acid interface. They have many applications in various industries including food, dairy, pharmaceutical, agrochemical, oleochemical and mainly in detergents. In this study btl2 gene (with and without signal sequence) was amplified from purified genomic DNA of Bacillus thermocatenulatus using primers designed based on the sequence in the GeneBank data base (GenBank X95309). PCR products were cloned in pGEM5zf vector. Then the genes were sub cloned into the pPIC9 expression vector under alcohol oxidase (AOX1) promoter (pYV128, pYV129). Molecular and restriction enzyme analysis confirmed cloning accuracy. The recombinant plasmids were linearized with BglII enzyme and transferred into Pichia pastoris host cells with electroporation. Finally, recombinant yeasts were cultured in BMGY medium and induced with methanol. Para nitrophenyl palmitate (pNPP) test and Immunoblotting method showed presence of the recombinant lipases in medium culture. The recombinant lipase was purified by ion exchange chromatography method and the specific activity was measured. The results showed that the recombinant lipase production was 18000U/L in flask culture, which 12000U/L purified recombinant lipase with 5728U/mg specific activity was recovered with this purification method.

Giant gourami is one of the important fishes for aquaculture and specially integrated fish farming in Southeast Asia. Because of the lack of precise data about the rearing temperature of this animal, this experiment is designed with three temperature treatments and the effects of temperature on survival, growth performance and some hematological parameters was explored. However the survival rate, weight gain, special growth rate, feed conversion ratio, daily growth index, blood glucose, total protein and haematocrit percent were identified and compared. Results show that there is no significant difference in these factors between the treatments (P>0.05). Thus we can say that in this species, in the range studied, there is thermal resistance. However, temperature 30 oC has the best conditions.

The present study was conducted during May-September, in Zarrinkola permanent Abbandan in Mazandaran Province. Reproductive phenology of Great Reed Warbler (Acrocephalus arundinaceus) was started with nest building behavior in mid May. It continues to fledged time in mid July. They leave breeding region in mid August. A total of 280 breeder pairs of Great Reed Warbler (A.arundinaceus) were counted in the Reeds (Phragmites australis). About %60 of clutch size had 5 eggs, %30 with 4 eggs, %10 with 3 eggs and the mean clutch size was 4.5 eggs per nest. Brood size was varied between 1-5 chicks that the Maximum and Minimum frequency were one chick (13 brood group) and five chicks (2 brood group), respectively. About %75.55 of eggs were hatched and %68.15 of these, were reached to fledged age. Breeding success was %71.10. There was not any significant difference between breeding success with clutch size and brood size (p>0.05). There was significant difference (p<0.05) between the rate of losses during the reproductive phenology stages. The maximum loss among the reproductive stages was during the incubation time (24.45%). It was affected by natural factors. There was not any significant correlation (p>0.05) between nest size, nest height of water level, water depth, distance of neighbor nest with breeding success. The minimum of Mayfield survival rate was in the incubation stage (0.959108), which was increased to post-nestling stage.

This study was carried out in order to evaluation of adaptation capability of 20 day-old Acipenser persicus larvae to different salinities for investigation of releasing possibility of them into the Caspian sea to provide for water shortage and appearing the drought crisis. To study the physiological adaptability ofA. persicus at May-June 2008, a total of 7000 larvae, 20 day-old (100-150 mg in weight and mean length of 9.6±0.14 mm) were stocked in fiber glass tanks (with volume 2 tones) at different salinities of 1, 3, 5, 7, 8 and 12 ppt (brackish water from the Caspian Sea) and also freshwater with salinity of 0.8 ± 0.1ppt. Larvae stocked in freshwater were used as the control group. During the experimental period which lasted for 72 h, survival rate, osmolarity of water in the culture system and osmolarity of water in interstitial tissues of larvae and the physical and chemical parameters of water were studied. Minimum mortality (0%) and maximum survival rate (100%) were recorded in the control group as well as in 1, 3 and 5 ppt salinities. Maximum mortality and minimum survival rate were observed in the experimental group with 12 ppt salinity (brackish water from the Caspian Sea) and were 0.2 ± 0.03 and 99.8 ± 0.04. In this group larvae became weak and inactive a few minutes after being introduced to the culture system and collected along the margins of the tank and showed no response to environmental clues and feeding. However, after 24 h, adapting to the conditions they returned to their normal state. Osmolarity of water in the culture medium and in interstitial tissues of larvae in changes salinities differed after 48 h. Minimum osmolarity was recorded in the control group (43±0.7 mOsmol l-1 in water and 252±2.5 mOsmol l-1 in interstitial tissues) and maximum osmolarity was recorded in the 12 ppt experimental group (359±1.1 mOsmol l-1 in water and 407±7.1 mOsmol l-1 in interstitial tissues) (P<0.05). Based on examinations, it seems that A. persicuslarvae have probably the potential to adapt to different salinities (1, 3, 5, 7, 8 and 12 ppt) by having the ability of osmoregulation system and maintaining electrolytes equivalent in hyperosmotic areas. By conducting further studies this potential can be considered as an advantage for their early release into natural ecosystems. The obtained results can be used to develop a new pattern for the culture of sturgeon larvae and may also be used to enhance restocking programs for these species.

Daucus carota seeds have different antioxidant agents and with respect to role of antioxidants in improvement of diabetes mellitus in this study the effect of alcoholic extract of D. carota seeds on serum levels of glucose, lipids and lipoproteins was investigated in type I diabetic male rats. Type I diabetes mellitus was induced in male wistar rats by injection of 70 mg/kg, i.p of streptozotocin. Before this and 5 days post injection blood samples were collected for measurement serum levels of glucose, triglycerides, cholesterol and lipoproteins. Diabetes was confirmed in rats having FBS above 250 mg/dL. Diabetic animals were divided to 5 groups received 100, 200, 300 mg/kg of extract, 600 mg/kg glibenclamide and 0.5 mL distilled water individually by gavage for 3 days. After 3 days rats sacrificed by decapitation and fasting blood samples were collected from cervical vein and above factors were measured with commercial kits by spectrophotometery. Results showed that administration of D. carota seeds extract (300 mg/kg) for 3 days decreased glucose serum level (p<0.05). Also extract at all doses decreased triglycerides, at dose 200 and 300 mg/kg decreased cholesterol and only at dose 200 mg/kg decreased LDL and VLDL serum levels (p<0.05). Thus it seems administration of D. carota seeds extract for 3 days has hypoglycemic and especially antihyperlipidemic effects in type I diabetic rats.

To identify the suitable lab mouse with more potency in embryo production, four commonly used strains of laboratory mice as NIH, NMRI, Balb/c and (Balb/c×NMRI) F1 were used in this experiment. One hundred and five mice of 7-8 weeks old were randomly selected from four strains and divided in 9 groups of 10 mice and 3 groups of 5 mice. Mice in group 2, 5, 8 & 11, received 5 IU and group 3, 6, 9 & 12 received 10 IU PMSG and HCG hormones intraperitonaly, group 1, 4, 7 & 10 were assigned as controls.Mice of all groups mated with their strain by trios. Results show mice which received 5 IU hormones, have respectively produced 9.5, 9.8, 38.6 & 34.8 embryos and other group of 10 IU, had 7.3, 11.4, 39.7 & 37.3 embryo. Number of embryos in Balb/c strain of group 8 with 9 in P<0.001 and also in F1 group 11 with 10 in P<0.05 were significantly different. In intergroup comparison, groups 2 & 5 with groups 8 & 11, also 9 with 3 & 6 there was significant difference. However NIH & NMRI strains were graded in low ovulators mice and Balb/c and F1 graded in high ovulators. Additionally, pronuclars in F1 embryos were very prominent. Results suggest the Balb/c strain is the most suitable mice for embryo production in comparison with the other strain worked in this study.

As all previous studies on ameliorative effects of garlic in renal damages have been done after diabetes induction, It was dedecided to assess its preventive roles on renal complications in rats with streptozotocin (STZ) -induced diabetes. Forty male wistar rats (250±20) were divided into 5 groups as follows: 1- Group normal (N) 2- Group Normal+Garlic (N+G), received garlic juice for 6 weeks.3- Diabetic (D) received STZ, 60 mg/kg BW /i.p.4- Group diabetic+garlic before (D+Gb), received garlic juice for 3 weeks before STZ injection and continued for more three weeks.5- Group diabetic+garlic after (D+Ga), three days after STZ injection, they received garlic juice for 3 weeks. Garlic juice was given by gavage (1ml /100g BW or (0.4 g/100gBW).Diabetes caused renal destruction (glomerular and proximal tubule hypertrophy, and atrophy of distal tubule epithelial cells). In addition, it leads to a decrease in renal weight. Garlic improved these changes so that the group receiving it before diabetes induction (D+Gb), showed more amelioration in variables than that receiving it after diabetes induction (D+Ga). In this study for the first time we showed that administration of garlic juice could play both preventive and therapeutic role on renal damage in diabetes.

Tintinnid ciliates are planktonic grazers of nanoplankton. They have a lorica (or shell) into which the ciliate cell can withdraw. The identification of planktonic ciliates, loricate (tintinnid) was investigated in the Iranian waters of the Oman Sea from fort of hormoz to pasabandar. Tintinnids surveys were conducted seasonaly during May 2007 (Premonsoon) -December 2007 (Postmonsoon) from 40 stations in Iranian waters. The samples were collected by vertical tows (closing net) using a 55 μm mesh planktonic net, with a mouth opening of 0.4m diameter. Depth of sampled stations in the studied area varied from 5 to 50 m. A total of 16 genus of tintinnids from 10 families, were identified. In this study 4 genus belonging to family Tintinnidae, 2 genus from family Xystonellidae, Ptychocylidae and Rhabdonellidae and familes Tintinnidiidae, Codonellidae, Epiplocylididae, Dictyocystidae, Metacylididae and Ascampbeliellidae any with 1 genus identify.Tintinnopsisfrom Codonellidae with 54% dominant and Dadayiella from Tintinnidae with 0.005% were abundance least. From sampling transects, transect 1 in pre and postmonsoon with abundance least and transect 2 in the premonsoon and transect 8 on postmonsoon most abundance. In order to Shannon's diversity index, Evenness and Richness doing in the statines. Cluster analysis of tintinnids at the sampling transects showed in the premonsoon transect 10 and transects 2 and 8 in the post monsoon to differ from other transects.

There are three species of Rat (R.norvegicus, R.pyctoris and R.rattus) in Iran. While application of such studies are very much important for their identification in urban areas and margins of the cities. In this study 27 rat specimens were sampled from Mashhad, Shiraz, Minab, Shahre-ray and Tehran were compared on the basis of morphologic, morphometric and chromosomal studies. Our investigations show that in spite of corbet's point of view in 1978, big palatine grooves of upper jaw is not as valuble as a key character. This character is able to distinguish just 64% of the species.This survey also shows that unlike the present reports that in karyotype of brown rattus is in NFa=62 instead of NFa=58. The study also show that R. Pyctoris of northeastern Iran is very much important from the point of view of taxonomy and Paleozoology.

To study the effect of water stress on some physiological characteristics of pinus seeds including germination percent, mean germination time, germination speed, germination energy and vigor index, a factorial experiment in Completely Randomized Block Design (CRBD) with five treatments of water potential and two tree species was conducted. The water potential of the germination substrates (0, -2, -4, -6 and -8 bars) was conducted using PEG-6000 solutions on Pinus brutia Ten. and P. halepensis Mill. Seeds. The seeds were kept for 37 days in germinator (16 h photoperiod at 1000 lux and at 20±0.5oC). The results indicated that water stress had significant effect on seed physiological characteristics in both species. Decreasing water absorption potential from 0 to -8 bars, significantly reduced germination percent, germination speed, germination energy and vigor index in both species. The seeds of P. halepensis were more sensitive to deficiency of water availability in comparison with P. brutia seed.

Leaf sections from 8-d-old dark-grown wheat (Triticum aestivum L.) were exposed to high salt stress (600 mM). Using low-temperature fluorescence spectroscopy and transmission electron microscopy the native arrangements of plastid pigments as well as the ultrastructure of the plastids were studied. Plastids from salt-treated leaves had highly swollen prothylakoids but the prolamellar bodies were regular. A slight intensity decrease of the short-wavelength protochlorophyllide (Pchlide) form fluorescing at 633 nm was observed. But the long-wavelength Pchlide form emitting at 656 nm showed no changes. The newly formed swollen thylakoids, after irradiation, has been showed traversing stromal strands. The PLB dispersal was partly inhibited and formed as an electron-dense structure, which remained after 8 h irradiation. The difference in fluorescence emission maximum of the main chlorophyll form in salt-stressed leaves (681 nm) and in control leaves (683 nm) indicated an arrested formation of the photosynthetic apparatus. Overall chlorophyll production was restricted during prolonged irradiation. Salt-stressed leaves returned to darkness after 3 h of irradiation had a reduced amount of Pchlide and reduced re-formation of regular net-like PLBs, compared to the control. Instead, the size of the electron-dense structures increased.This study reports the salt-induced swelling of PTs and reveals traversing stromal strands. Although the PLBs were intact and the Pchlide fluorescence emission spectra appeared normal after salt stress in darkness, plastid development to chloroplasts was highly restricted during irradiation.

Forking defect is probably the most serious stem-quality problem in beech trees.Forking defect greatly reduces wood yield and wood quality. For tree breeding program, it is important to know about the causes of the forking and the genetic component of it.Genetic differentiation of forked and monopodial tree groups is described in seven naturally regenerated, mixed and pure beech (Fagus orientalis) populations along Hyrcanian forests consisting of seeds of ten forked and monopodial 100 trees (each tree 7 seeds). After testing 6 microsatellite loci originally developed for F. sylvatica, each seed was genotyped at four well-scorable microsatellite loci. Based on the mean genetic distance between seeds of each tree genetic structures were studied.Population differentiation was moderate and differed significantly (Fst=0.13-0.22) among forked and monopodial tree groups. Although, tendency of a strong family structure among seeds of forked and monopodial genotypes is obvious, but the results show that population genetic structures are also influenced by unpredictable factors such as wind direction at a thesis and can be therefore, varied from year to year. It is recommended that seed collections should cover large areas in order to prevent a preponderance of few families and a reduction of the adaptive potential of the next generation.

This study was done to investigate of the relationship between biodiversity of woody and herbaceous species and environmental factors in lowland forests of eastern Nowshahr. Selective sampling method was considered with 46 sample plots and the area of sample plots was determined by using minimal area method. In studied area 100 species of 92 genera in 48 families were recognized. Biodiversity indices of Shannon-Wiener and richness index of Margalef and Menhenic were used for calculation of biodiversity. Vegetation cover and environmental factors including physiography, soil physical and chemical properties were studied on the basis of deterned correspondence analysis and canonical correspondence analysis and after ordination method performance, obtained axes were extracted. At the next stage the correlation between biodiversity indices and CCA and DCA ordination axes were studied. Then correlation between determined axes and environmental factors as studied and environmental factors that had significant correlation was recognized. Finally the correlation between biodiversity indicators and mentioned environmental factors was studied. The results indicated that each 4 mentioned indices have positive significant correlation with sand, slope and elevation and they have negative correlation with silt, clay, potassium and nitrogen.

Scientists have made much effort to identify mutants which can help them to recognize gibberellin synthesizing pathway in plants. Therefore, effects of different concentrations of three chemical agents named Uniconazol, Pronamide and Isoxaben on Arabidopsis thaliana growth was investigated, using existing variable Arabidopsis gene pools, to find mutants by which inhibitory effects of the mentioned chemicals can be prevented.Critical concentration of the chemicals on seed germination and vegetative growth of Arabidopsis was first determined. Interaction effects of the levels close to critical concentration of the chemicals by which the mutants may be identified were recognized.Combination effects of Uniconazol, Isoxaben and Uniconazol, Pronamide on seed germination and vegetative growth of Arabidopsis were investigated by two separate experiments. The combinations with the higher interaction effects were specified to be used by screening of several genetically variable gene pools of Arabidopsis thaliana.Significant interaction effects on vegetative growth of the Arabidopsis species were observed between several levels of the chemicals. At the highest applied level of Uniconazol (395 nM) the applied levels of Isoxaben and Pronamide showed more effects on roots than on hypocotyls growth. Pronamide effects on the reduction of hypocotyl and root growth were much more than those of Isoxaben. The chemical combinations effects showed reverse effects on root tip meristems. Although by increasing the chemicals concentration, hypocotyl and root length were decreased, increasing the concentrations, root tip meristem thicknesses were also increased. The variable Arabidopsis gene pools were sown on media containing the combinations of the chemicals concentration. A number of seeds were germinated and grown on the media. These were grown to maturity and seed production. Seeds were collected on the grown plants to be employed as mutants resistant to inhibitory effects of the chemicals in the future.