Ultrastructure changes in buffalo (Bubalus bubalis) oocytes before and after maturation in vitro with sericin

The aim of this research was to identify the changes in the cytoplasmic ultrastructure of immature and matured oocytes in buffalo (Bubalus bubalis ). Oocytes were matured in vitro in tissue culture medium?199 with and without sericin, and then analyzed by light and transmission electron microscopy. The experiment result showed that the nuclear maturation rate of buffalo oocytes was significantly higher in the presence of sericin (80.6%) than without sericin (68.1%) (P  < 0.05). The immature oocytes were characterized by cortical granule clusters in the ooplasm and the absence of perivitelline space (PVS ). In contrast, the oocytes matured either with or without sericin showed the formation of PVS , erected microvilli, the migration of cortical granules to the cytoplasmic periphery, and the clear appearance of the mitochondria and vesicle in the oolemma. Interestingly, matured oocytes with sericin have smaller cortical granules than do immature oocytes (P  < 0.05). In conclusion, supplementation of 0.05% sericin in the maturation medium can enhance the maturation rate of buffalo oocytes. Several cytoplasmic ultrastructures were relocated and modulated during the in vitro maturation process of buffalo oocytes: PVS development, cortical granules migration to periphery, and mitochondria and vesicles in the cortical region. The ultrastructure was similar between the groups with and without sericin.     

A method to study the effects of chemical and biological reduction of molybdate to molybdenum blue in bacteria

In this research, we modify a previously developed assay for the quantification molybdenum blue to determine whether inhibitors to molybdate reduction in bacteria inhibits cellular reduction or inhibit the chemical formation of one of the intermediate of molybdenum blue; phosphomolybdate. We manage to prove that inhibition of molybdate reduction by phosphate and arsenate is at the level of phosphomolybdate and not cellular. We also prove that mercury is a physiological inhibitor to molybdate reduction. We suggest the use of this method to assess the effect of inhibitors and activators to molybdate reduction in bacteria.     

Bacterial canker of olives caused by of Pseudomonas syringae pv. syringae in Iran

Guilan is one of the main province olive oil producers in Iran. The culture of olive trees is of considerable importance. One problem that affects Iran olive orchards is a disease bacterial canker caused by Pseudomonas syringae pv. syringae. In this research, the bacterium was recovered from sunken brown stem lesions on 2-year-old olive trees cv. Marie, during survey from olive orchards in different areas of Guilan province. Samples were taken from infected tissues and were washed with sterile distilled water and crushed in peptone water. Then 50 μl of the extract was cultured on NA and King's B medium containing cyclohexamid antibiotic (50 μg/ml). After 48–72 h, bacterial colonies were selected. Based on morphological, physiological, biochemical, pathogenicity properties and PCR methods with specific primers the predominant pathogenic type was identified as P. s. pv. syringae. This is the first report of the existence of P. s. pv. syringae on olive trees in Iran.     

Toxicological and hematological effect of <Emphasis Type="Italic">Terminalia arjuna</Emphasis> bark extract on a freshwater catfish, <Emphasis Type="Italic">Heteropneustes fossilis</Emphasis>

Increasing demand for eco-friendly botanical piscicides and pesticides as replacements for harmful synthetic chemicals has led to investigation of new sources of plant materials. Stem bark of Terminalia arjuna, which has been used as a popular folk medicine since ancient time, was examined for its piscicidal activity. This study aims to determine toxicity of ethanol extract of T. arjuna bark on fresh water stinging catfish (Heteropneustes fossilis), along with evaluation of changes in hematological parameters of the fishes exposed to a lethal concentration. The percent mortality of fishes varied significantly in response to concentrations of the extract and exposure times (between exposure time F = 36.57, p < 0.001; between concentrations F = 39.93, p < 0.001). The lethal concentrations (LC₅₀) of ethanol extract were found to be 12.7, 8.94, 5.63 and 4.71 mg/l for 24, 48, 72 and 96 h, respectively. During acute toxicity test, blood samples of treatment fishes showed significant decreases in the red blood cells count, hematocrit content, hemoglobin concentration, mean corpuscular hemoglobin concentration and plasma protein level when compared to those of the control group, while there were significant increases in the mean corpuscular volume, mean corpuscular hemoglobin, white blood cells count and plasma glucose concentration. These results suggest that T. arjuna bark extract could be considered as a potent piscicide due to its toxic effect on fish, particularly fish hematology.     

Applications of polysaccharides (β-glucan) for physiological and biochemical parameters for evaluation rice tolerance under salinity stress at seedling stage

Salt stress is considered to be the most important abiotic stress and is the main problem in the interruption of the metabolic processes of plants, thereby limiting crop production. The present study was carried out to examine the effects of exogenously applied mushroom polysaccharides (β-glucan) on the growth of two rice varieties of Oryza sativa L. (MRQ74 and MR269) seedlings grown in vitro in 200 Mm sodium chloride (NaCl). Growth characteristics, including shoot and root height, and fresh and dry weight of salt-stressed rice seedlings were inhibited by sodium chloride treatment, the degree of which depends on the rice variety. The negative effects of salinity stress resulted in an imbalance of N, K⁺ Na⁺ and Na/K ratios and biochemical analysis activities a degradation of chlorophyll content in the plants. However, treatment with exogenously applied polysaccharides (β-glucan) ameliorated the stress generated by NaCl and improved the parameters mentioned above. The significance of the changes in growth and metabolism to salt stress tolerance in rice seedlings are discussed in the paper.     

Fatty acid composition,fat deposition,lipogenic gene expression and performance of broiler fed diet supplemented with different sources of oil

The present study assessed the effect of feeding palm oil (PO), sunflower oil (SO) and their combination on performance, fat deposition, fatty acid composition and lipogenic gene expression of broilers reared for 42 days. A total of 144 1‐day‐old broilers (Cobb500) were randomly allotted into four treatment diets with each having six replicates of six chicks in each replicate following a completely randomized design. Live weight gain and feed efficiency was significantly (P < 0.05) higher in birds fed with a combination of oil sources compared to controls. Birds fed with the combination of oil and SO alone had higher carcass yield and lower abdominal fat. Higher (P < 0.05) concentrations of unsaturated fatty acids (UFA) and lower concentrations of palmitic acid and saturated fatty acid (SFA) was found in birds fed SO alone and combinations of SO and PO. Furthermore, the outcomes showed that birds fed diet supplemented with SO and the combination of SO and PO down‐regulated gene expression of key hepatic lipogenic enzymes of fatty acids synthase (FAS), acetyl‐CoA carboxylase (ACC) and stearoyl‐CoA desaturase (SCD). These findings suggest that the diet containing the combination of 2% PO and 4% SO may reduce hepatic lipogenesis, as well as lower abdominal fat content of broilers.