مجله زیست شناسی ایران
سال بیست و سوم شماره 2 (خرداد و تیر 1389)

Some important Strategies to increase recombinant protein yield in plants include expression of protein in suitable plant tissue and improvement of protein stability and accumulation by targeting into subcellular organs using specific targeting signals. The ER contain different molecular chaperons and isomerase for folding of nascent proteins، which can prevent aggregation and formation of incorrect three dimensional structure and promote correct protein folding leading to recombinant protein stability and accumulation. In this perspective، seed-based platforms are particularly attractive because they allow recombinant proteins to stably accumulate at a relatively high concentration in a compact biomass، which is beneficial for extraction and downstream processing. In this research for human Gamma interferon expression in Brassica napus seeds and targeting into ER، we used seed specific promoter (Napin) and C-terminal KDEL sequence (ER retention signal). The fragment was cloned into pGEM®-T Easy vector and then was confirmed by PCR، restriction enzyme analysis and sequencing. The authentic PCR fragment was subcloned into a plant binary vector (pBI121). This construct cassette (pBI IFNγ) was transferred to A. tumefaciens LBA4404 and then used to transform B. napus using an Agrobacterium-mediated petiole cotyledonary transformation. The transformed plants were screened on antibiotic-contained media The presence and expression of the transgene was confirmed in the transformants by PCR and SDS-PAGE. ELISA test was used for biological activity.

At present bio-ethanol is considered as being one of the most important biotechnology products. In the world today، among which Saccharomyces cerevisiae yeast has the greatest usage in this industry. Moreover molasses is considered as an adequate carbon source for producing Ethanol in Iran due to its low cost and abundance، in addition to its large amount of sugar. The purpose of the study is first the optimization of inoculum''s size and subsequently the optimization of sugar concentration in the crop yield. With due regards to the importance of vitamins، the effect of two vitamins، Biotin & Pentatonic acid، was also studied. Initially sugarcane molasses was analyzed and based on the chemical compounds of the analyzed molasses and the general formulation of yeast، the compound of the culture media as per productive industries was calculated. Following that various percentages of inoculum were added. Ultimately the quantity of the yield and productivity were computed and analyzed using statistical methods. The results showed that inoculum''s size of 4% v/v had the highest productivity of Ethanol. In addition various brix of molasses were studied. The results showed that 17/5 brix (with a sugar concentration of 110 g/l) had the highest productivity of Ethanol. Furthermore it was seen that the addition of Biotin to the intended culture media had a significant effect on the productivity of fermentation، whereas Pentatonic acid leads to decreasing in fermentation time and consequently an increase in productivity.

Biosurfactants are amphipathic compounds produced by a wide variety of microorganisms and due to their unique properties are used by many industries. Hence، maintenance and stability of their functional properties against various environmental conditions is a grave concern. To achieve the goal of production and application of biosurfactant in petroleum industry، a native strain of Bacillus subtilis was isolated from hydrocarbon contaminated soil using microbial screening procedures. Biosurfactant production was carried out in shaker incubator during a nine-day period of fermentation at 30°C and 200 rpm. After separating microbial biomass، the influence of salt treatments (concentration of 1-10% NaCl)، pH variations (1-13) and also heat treatments (room temperature up to 120°C for 30 minutes) on function of crude biosurfactant existing in fermentation broth were investigated using tensiometery. According to this study، biosurfactant produced by native strain of B. subtilis was resistant to heat treatment and comparing to untreated control (23. 3 mN/m) did not show noticeable difference. There was a slight variation in surface tension in pH 5-9; however، it seemed that acidic pH had more severe impact on biosurfactant function and subsequently annihilated its function in pH below 5. Biosurfactant، which exists in culture filtrate، was relatively resistant to the salt concentration of 1-10% and maximum surface tension was at 10% salt concentration (28. 6 mN/m) which indicates only a minor difference comparing to that of control.

Brine shrimp (Artemia.) is fascinating organism from subphylum Crustacean، order Branchiopoda، family Artemiidae. Artemia brine shrimps inhabit saline and hypersaline ecosystems and have many tolerance against salinity changes. Urmiah Lake is the most important habitate of Artemia in Iran. Artemia is also reported from Kale-shour located in 35 km north of Gonabad، south khorassan province، Iran. In this study collected Artemia from Gonabad Kale-shour were compared with Artemia urmiana Gunther (1900) and Artemia parthenogenetica from Urmiah Lack using morphometric characters. Cysts samples collected from Kale-shour and Artemia urmiana and Artemia parthenogenetica were obtained from Urmiah Fisheries Company (shilat) Research Center. The Cysts were cultured separately in 20 L aquarium approximately under constant physical and chemical conditions (salinity 62 ppt، temperature 20 ± 1 C˚، PH ≈ 8، slowly and continually aeration، flourscent light with 40 cm distance from aquarium surface). All samples were fed with rice bran and unicellular algae. After 35 days 30 chosen mature female of each culture were narcotized with chloroform and eight quantitative characters (total length، abdominal length، abdominal width، length of furca، head width، distance between compound eyes، eyes diameter، length of the first antenna) were measured under measuring microscope to the nearest 0. 001 mm. Data were analysis using the statistical software SPSS 10 and multivariate analysis، result show that Kale-shour Artemia are significantly different from Artemia urmiana، but the Kale-shour Artemia and A. Parthenogenrtica are identical. Two populations could belong to A. parthenogenetica species. Artemia، Kale-shour، Urmiah، morphometric.

In this research biochemical characteristics of semen at the spawning season in Mahisefid investigated to 3 terms and Samples from Shiroud river at Mazandaran province. The result at the beginning، middle and end of spawning season in Mahisefid were: Na+ 212. 03 ± 4. 65، 221. 47 ± 5. 64، 216. 33 ± 19. 26; k+ 50. 82±7. 1، 20. 43±9. 31، 26. 33±20. 36، Ca+ 0. 91±0. 25، 0. 57±0. 31، 0. 47±0. 37; Mg2+ 1. 51±0. 52، 1. 72±0. 63، 1. 43±0. 29; Na+/K+ ratio 4. 26 ± 0. 71، 12. 63 ± 4. 81، 15. 84 ± 16. 01; Na+/Ca2+ 249. 75 ± 74. 89، 572. 17 ± 372. 64، 1617. 42 ± 2661. 56; Na+/Mg2+ 153. 53 ± 45. 72، 141. 57± 41. 39، 156. 42 ± 30. 81; K+/Ca2+ 60. 94 ± 25. 4، 48. 23 ± 32. 69، 134. 64 ± 219. 06; K+/Mg2+ 36. 87 ± 11. 66، 12. 53 ± 5. 37، 18. 11 ± 12. 87; Ca2+/Mg2+ 0. 68 ± 0. 3، 0. 35 ± 0. 21، 0. 32 ± 0. 21; (unit of ions and rations are mM/l); glucose 4. 94 ± 3. 64، 3. 02 ± 1. 55، 4. 94 ±5. 58; total protein 574. 29 ± 344. 96، 598. 57 ± 408. 35، 687. 14 ± 465. 89 and cholesterol 16. 24 ± 15. 39، 17. 27 ± 16. 13، 9. 45 ± 5. 54 (unit of glucose، total protein & cholesterol mg/dl). K+ and K+/Mg2+ were significant (P<0/01) and also Ca2+ and Ca2+/Mg2+ at the spawning season in Mahisefid were significant (P<0/05). But Na+، Mg2+، Na+/K+، Na+/Ca2+، Na+/Mg2+، K+/Ca2+، glucose، total protein and cholesterol of seminal plasma at the spawning season in Mahisefid were not significant (P>0/05).

Populations of Asiatic houbara bustard (Chlamydotis maqueenii) have been declining throughout its geographical range. Beside in situ conservation activities، captive breeding of this species as an effective conservation measure has previously been conducted in a few countries. This paper contains the results of investigational captive breeding of Asiatic houbara in Iran which has been conducted for the first time. Eggs detected in breeding habitat of houbaras were transferred to standard incubation systems in the Harat captive breeding centre. Chicks were fed by vegetation protein and flour yellow beetle (Tenebrio molitor). Of the 9 eggs transferred to incubation system، 8 were successfully hatched. Comparing the weight of captive bred houbara bustards at 3 years of age (females: 1318. 5 g ± 26. 5 SE; males: 1412. 5 g ± 27. 5) with captured ones from the wild (females: 1832. 6 g ± 37. 3 SE; males: 2227. 4 g ± 92. 4) showed significant difference between these two groups (P <0. 001). In contrast، adult houbara bustards kept in the captive breeding centre for a year (2106. 3 ± 47. 0 SE) showed an increase in their weight compared to their initial weight at the time of capture (1931 g ± 70. 8 SE) (paired t = 6. 43; P = 0. 008). The energy content of houbara''s eggs was estimated for the first time as 273. 8 KJ. Linear relationships were obtained between chick weight and egg mass (R2 = 0. 89; P < 0. 001) as well as between chick weight and egg-shell mass (R2 = 0. 87; P < 0. 001). Variations in egg mass were associated with variations in egg dimensions (breadth & length). This study provided new information on the biology of Asiatic houbara and verified the possibility of captive breeding of this species in Iran using the determined diet. Concerns about captive breeding of this species are discussed.

Ghrelin increases food intakes and body weight. [D-Arg-1، D-phe-5، D-Trp-7،9، Leu-11] Substance-P (an analog of Substance-P) inhibits the stimulatory effect of ghrelin on food intakes. Thyroid hormones have an important role in the regulation of body weight too. So، the goal of this study was to determine the effect of different doses of ghrelin and also، the effect of interaction between ghrelin and analog of Substance-P on thyroid axis activity. Thirty six rats in 4 groups received saline or different doses of ghrelin (1، 5 or 10nmol) and forty rats in 4 group received simultaneous injection of ghrelin (5nmol) and different doses of analog Subsatnce-P (5، 10 or 20nmol) or saline. Blood samples were collected and were analyzed by RIA. ICV infusion of 5 or 10 nmol of ghrelin significantly decreased thyroid hormones concentration compared to saline and 20nmol of analog of substance P blocked the inhibitory effect of ghrelin on thyroid axis activity.

So far 194 mammal species have been recorded form Iran including brown bear (Ursus arctos) and black bear (Ursus thibetanus). In Iran، the distribution of brown bear is confined to mountain forests of Alborz and Zagros and the Fars province is southern most range boundary for this species. In this study، the brown bear distribution was determined and then its habitat status was studied from topographic and climatic points of view using of Arc GIS 9. 2 software. Based on combination of different data layers with distribution map of this species، it is found that more than 80 % of its signs and traces are observed in mountain regions، more than 50 % in elevation range of 2002-2405m، 48. 4% in slope range of 10-15% and 45. 34 % in semidry climate، 41. 93% in precipitation range of 600-700 mm in year and mostly in cool regions. The results of this survey could be important in modeling habitats of this species and used for its better habitat management.

In this study the effect of starvation on some morphological (weight and length body; condition factor، liver weight، hepatosomatic index، visceral fat content and tissue moisture) and haematological (plasma glucose; protein; cholesterol; cortisol levels and haematocrit) characters were investigated. After acclimation to experimental conditions، two groups of 45 fish (140±20g)، were assigned to two outdoor concrete ponds (4m × 2. 7 m × 1. 5 m each)، as fed and unfed groups. After commencing the experiment، one group was deprived of food and the second group was fed at the rate of 1. 7 % of bw/ day with a commercial diet. Sampling was carried out at beginning and every ten days intervals up to 60 days after start of the experiment by taking five fish randomly from each group. Results indicate that starvation significantly effects body weight and length; liver weight، and hepato-somatic index (p<0. 05). Despite the great variation and differences in fat content، moisture and condition factor، no significant difference were found among the fed and unfed groups. Nevertheless starvation affected plasma glucose and cortisol level (p<0. 05)، but the protein level was not affected significantly. Although haematocrit values recorded during starvation period showed no significant difference with the initial values، however، a significant differences was found between the fed and unfed groups at the end of the experiment (p<0. 05). Cholesterol level declined initially، so that no significant differences were found between the fed and unfed fish. In conclusion، results indicate a correlation between starvation and some of the morphological and haematological characters، but it was more pronounced with morphological characters which could possibly be justified with a high homeostatic potential of blood.

Medusae of cnidaria were identified in various locations of the world but in Asia، specially Iran، spacious study in this field wasn’t done. Main purposes of this study were: Taxonomic identification and determination of distribution of medusae. Studied medusae have been sampled in 2 station July 2005 until June 2006. Monthly sampling were collected with 300µm mesh size plankton net in oblique tow from near bottom to surface and samples of macro medusae were collected from local fisher man. Results showed that medusae belonging to 2 class، 4 order، 11 family، 13 genus and 16 species. The identified species are as follows: Phialucium carolinae، Eirene kambara، Eirene hexanemalis، Liriope tetraphylla، Diphyes disper، Diphyes chamisonis، Obelia sp.، Lensia subtiloides، Aequrea parva، Phiallela sp.، Eutima levuka، Octophialucium indicum، Octophialucium medium، Cassiopea andromeda، Catostylus perezi، Rhizostoma sp. Analysis variance azmoon were used to impact of station and mounth on medusae abundance. As a result medusae abundance showed significant variation in different mounths.

Structure of hearing organ especially middle ear has different specialization that provides response to wide range of sound frequencies. In this research external morphology and internal anatomy of tympanic bullae was studied using histological techniques and electron microscope in three species of genus Meriones (M. persicus، M. libycus، and M. crassus). Our results indicated adaptive value of tympanic bullae characters as well as increasing in the volume of tympanic bullae in the genus Meriones. This part is larger in M. crassus and M. libycus that live in desert habitats. Also it was seen that tympanic bullae in desert species has penumatization. Maximum penumatization of this part is occurred in desert species. In addition، middle ear ossicles have less hardness and more volume that increase reception possibility for higher sound frequencies. These characters enhance the ability of adaptation with desert environment such as; escape from predators، finding mate and returning to house.

Spinal cord slice culture from mammals is one of important methods for studing spinal cord injury، evaluation of cell viability and cell death mechanisms. The aim of this study was to establish an in vitro model for culturing spinal cord slice by MTT [3 – (4،5- dimethy lthiazol-2-yl) -2،5-diphenyl tetrazolium bromide] assay. The thoracic region of spinal cord from adult mouse was transversally sliced to 300-600 µm، using a tissue chopper. The slices were incubated with culture media in the presence or absence of serum for different period of time. MTT assay was used to assess the viability of the slices. After 24 h، 400-µm-thick slices displayed a significant increase (‍‍‍P<0. 01) in viability compared to both thinner and thicker slices. At this time point، a significant increase (P<0. 001) was found in the viability of slices cultured in serum containing medium compared to serum free medium. Qualitative MTT assay also revealed an intense staining in both gray and white matter of freshly prepared slices. However، after 24 h، the distribution of MTT staining was less pronounced in the slices particularly in slices cultured in serum-free medium compared to serum containing medium. Our results suggest that MTT assay is a useful tool for evaluating adult mouse spinal cord slices and that both slice thickness and the presence of serum into the medium affect viability in such slices.

Brassinosteroids are phytohormones possessing a wide spectrum of antistress activity. The effects of 24-epibrassinolise on leaf water content، leaf area، lipid peroxidation، electrolyte leakage، protein content and ethylene production were investigated in canola (Brassica napus L. cv. Fusia) seedling under water stress. The seeds were sown in plastic pots containing sand، clay and peat (in proportion of 1:1: 1). Solution of 24-epi-brassinolid at 10-7 M concentration containing 0. 01% Tween-20 (polyoxyethylene sorbitan) was sprayed on leaves at intervals of 1، 2 and 3 weeks after sowing. Control plants were sprayed with 0. 01% Tween-20. One month after sowing، plants were harvested. Lipid peroxidation level and electrolyte leakage significantly increased under water stress but decreased when 24-epibrassinolid were applied، revealing that less oxidative damage occurred in this group. Protein content، water content and ethylene production was decreased when 24-epibrassinolide were applied even under water stress and was higher than control plants. Leaf area was significantly decreased under water stress but 24-epibrassinolide had no appreciable effect on the leaf area. Results suggested that، 24-epibrassinolide can considerably alleviate oxidative damage induced by water stress conditions.

The aim of this study was finding the Autecology of sumac species (Rhus coriaria) in Khorasan province (Binalood Mountains). Sampling of soil and plant vegetation carried out in two sites (Darroud and Bojan with 5 and 6 hectare surface area respectively). Climate of these sites was semi arid. Samples gained from 33 plots with systematic random method by using of 50 * 50 meter net. The factors of tree measurements including tree height، crown height، crown percentage، tree density and seedling density measured in all plots. ANOVA test showed: 1- Among aspects the factors of seedling density، crown percentage and crown height had significant differences،2- the effect of slope was significant on tree density and crown percentage،3- The increase of stone percent decreased crown percentages، tree density and crown height. 4- Increase of gravel percent deduced tree height، crown percentage and tree density. In general، due to little requirements of this species to water and nutrient and due to distribution of this species in soils with medium nutrient levels and even week soils and to widespread distribution of sumac species in Iran، utilization of sumac for development of green space in arid and semi-arid areas can be ordered.

In this research loquat seeds were planted in the factorial experiment in randomize completely design with and without GA3 present and in different levels of cold period (0،2،4،6 weeks) and was germination compared percentage and subsequent seeding growth of loquat. After 3،4،5 and 6 weeks after sowing، all tested moist-chilling treatments with the different periods (2،4،6 weeks) seed germination was significantly higher than non-chilled or only GA3 and moist chilling treatments either alone or in combination significantly improved seedling characteristics including seedling length، leaf area، root dry weight and total chlorophyll compared with those of the control. Increasing the moist- chilling period over 4 weeks had no significant effect on the seedling characteristics. Three weeks moist- chilling treatment significantly surpassed the 2-week moist chilling treatment in leaf area، root dry weight and total dry weight of the obtained seedling، but significantly decreased both seeding length and total chlorophyll. The invigorating effect of GA3 treatment on the subsequent seedling growth was significantly lower than that of the tested moist chilling periods. In sum، the best treatment for seed germination and subsequent seedling growth of loquat was moist chilling for 2 or 4 weeks followed by soaking in 500 ppm GA3 solution.