Effect of Incorporation of Additives in Tris‐Based Egg Yolk Extender on Buffalo (Bubalus bubalis) Sperm Tyrosine Phosphorylation During Cryopreservation

Phosphorylation of tyrosine residues on sperm protein is a known indicator of capacitation and a major intracellular signalling event. There is evidence that sperm cryopreservation promotes tyrosine phosphorylation and is associated with reduced fertility of spermatozoa. Under this study, cryoprotective role of different additives namely taurine, trehalose, catalase and 4‐bromophenacyl bromide on buffalo sperm quality was evaluated. Buffalo semen was cryopreserved in tris‐based egg yolk extender supplemented with additives like taurine (50 mm ) or trehalose (100 mm ) or 4‐bromophenacyl bromide (200 μm ) or catalase (100 U/ml) and used for assessment of levels of tyrosine phosphorylation in frozen‐thawed spermatozoa. The results obtained were compared with the level of protein tyrosine phosphorylation of semen cryopreserved in tris‐based egg yolk extender without additives. Proteins were extracted from a total number of nine ejaculates from three individual buffalo bulls chosen at random and analysed for tyrosine phospho‐proteins using SDS–PAGE followed by immunoblotting. Monoclonal anti‐phosphotyrosine antibody (Clone pT‐154) was used as primary antibody followed by treatment with HRP‐conjugated secondary antibody. Signals were detected on X‐ray film using chemiluminescence. Nine proteins (p20, p30, p32, p38, p49, p56, p59, p72 and p86) were found to be tyrosine phosphorylated in cryopreserved spermatozoa. Supplementation of additives significantly (p<0.05) reduced the level of protein tyrosine phosphorylation in spermatozoa. Moreover, this study showed improved (p<0.05) post‐thaw motility, viability and membrane integrity of spermatozoa on addition of these additives. The results obtained clearly indicate reduced level of capacitation like changes on supplementation of additives in terms of protein tyrosine phosphorylation.     

Biosorption kinetics of Cu (II) ions removal from aqueous solution using bacteria

The present study highlights the effective removal of Cu (II) ions from synthetic solution using bacteria such as B. subtilis, P. aeruginosa and E. cloacae. Batch biosorption studies show that the biosorption of B. subtilis is effective when the concentration ranges from 25-200 mg L(-1). Biomass dosage, pH and the initial metal ion concentration have a profound effect on the biosorption process and this is reported in this study. In order to understand the nature of the biosorption process, Langmuir and Freundlich isotherm models were applied. Pseudo first and second order models were used to study the biosorption kinetics. The results show that these bacterial strains are very much suitable for the removal of Cu (II) ions. Being cost effective and efficient in toxic metal ion removal, these bacteria can be used on a large scale.     

Effect of coconut palm wine (Toddy) on carbohydrate metabolism in pregnant rats and fetuses

The objective of this study was to determine the effects of an alcoholic beverage (Toddy) and the equivalent quantity of ethanol on carbohydrate metabolism in utero. Female rats were exposed to Toddy from coconut palm (24.5 ml/kg body weight/day) and ethanol (0.52 ml/kg body weight/day) for 15 days before conception and throughout gestation. On the 19th day of gestation, hypoglycemia was seen in both the treated groups, but it was more in the Toddy-treated group. Synthesis of glycogen was elevated on exposure to ethanol/Toddy but its degradation was enhanced only in alcohol-exposed rats. Key enzymes of citric acid cycle and gluconeogenesis were inhibited on administration of both alcohol and Toddy. Activity of glycolytic enzymes were increased. Toddy seemed to potentiate the toxicity induced by alcohol, indicating the additive effects of congeners.     

Chitosan nanoparticles enhance developmental competence of in vitro-matured porcine oocytes

Oxidative stress is inevitable as it is derived from the handling, culturing, inherent metabolic activities and medium supplementation of embryos. This study was performed to investigate the protective effect of chitosan nanoparticles (CNPs) on oxidative damage in porcine oocytes. For this purpose, cumulus–oocyte complexes (COCs) derived from porcine slaughterhouse ovaries were exposed to different concentrations of CNPs (0, 10, 25 and 50 µg/ml) during in vitro maturation (IVM). Oocytes treated with 25 µg/ml CNPs showed significantly higher levels of GSH, along with a significant reduction in ROS levels compared to control, CNPs10 and CNPs50 groups. In parthenogenetic embryo production, the maturation rate was significantly higher in the CNPs25 group than that in the control and all other treated groups. In addition, when compared to the CNPs50 and control groups, CNPs25-treated oocytes showed significantly higher cleavage and blastocyst development rates. The highest concentration of CNPs reduced the total cell number and ratio of ICM: TE cells in parthenogenetic embryos, suggesting that there is a threshold where benefits are lost if exceeded. In cloned embryos, the CNPs25 group, as compared to all other treated groups, showed significantly higher maturation and cleavage rates. Furthermore, the blastocyst development rate in the CNPs25-treated group was significantly higher than that in the CNPs50-treated group, as was the total cell number. Moreover, we found that cloned embryos derived from the CNPs25-treated group showed significantly higher expression levels of Pou5f1, Dppa2, and Ndp52il genes, compared with those of the control and other treated groups. Our results demonstrated that 25 µg/ml CNPs treatment during IVM improves the developmental competence of porcine oocytes by reducing oxidative stress.     

Low Temperature Effects during Seed Filling on Chickpea Genotypes (Cicer arietinum L.): Probing Mechanisms affecting Seed Reserves and Yield

Chickpea is sensitive to cold conditions (<15 °C), particularly at its reproductive phase and consequently it experiences significant decrease in the seed yield. The information about the effects of cold stress on chickpea during the seed filling phase is lacking. Moreover, the underlying metabolic reasons associated with the low temperature injury are largely unknown in the crop. Hence, the present study was undertaken with the objectives: (i) to find out the possible mechanisms leading to low temperature damage during the seed filling and (ii) to investigate the relative response of the microcarpa (Desi) and the macrocarpa (Kabuli) chickpea types along with elucidation of the possible mechanisms governing the differential cold sensitivity at this stage. At the time of initiation of the seed filling (pod size ∼1 cm), a set of plants growing under warm conditions of the glasshouse (temperature: 17/28 ± 2 °C as average night and day temperature) was subjected to cold conditions of the field (2.3/11.7 ± 2 °C as average night and day temperature), while another set was maintained under warm conditions (control). The chilling conditions resulted in the increase in electrolyte leakage, the loss of chlorophyll, the decrease in sucrose content and the reduction in water status in leaves, which occurred to a greater extent in the macrocarpa type than in the microcarpa type. The total plant weight decreased to the same level in both the chickpea types, whereas the rate and duration of the seed filling, seed size, seed weight, pods per plant and harvest index decreased greatly in the macrocarpa type. The stressed seeds of both the chickpea types experienced marked reduction in the accumulation of starch, proteins, fats, crude fibre, protein fractions (albumins, globulins, prolamins and glutelins) with a larger decrease in the macrocarpa type. The accumulation of sucrose and the activity levels of the enzymes like starch synthase, sucrose synthase and invertase decreased significantly in the seeds because of the chilling, indicating impairment in sucrose import. Minerals such as calcium, phosphorous and iron as well as several amino acids (phenylalanine, tyrosine, threonine, tryptophan, valine and histidine) were lowered significantly in the stressed seeds. These components were limited to a higher extent in the macrocarpa type indicating higher cold sensitivity of this type.     

Exogenous Application of Abscisic Acid Improves Cold Tolerance in Chickpea (Cicer arietinum L.)

Chickpea suffers cold stress (<10 °C) damage especially during reproductive phase resulting in the abortion of flowers and pods, poor pod set, and reduction in seed yield and seed quality. One of the ways in modifying cold tolerance involves exogenous treatment of the plants with chemicals having established role in cold tolerance. In the present study, the chickpea plants growing under optimum temperature conditions (28/12 °C, as average maximum and minimum temperature) were subjected to cold conditions of the field (10–12/2–4 °C; day/night as average maximum and minimum temperature) at the bud stage. Prior to exposure, these plants were treated exogenously with 10 μm abscisic acid (ABA) and thereafter again after 1 week of exposure. The stress injury measured in terms of increase in electrolyte leakage, decrease in 2,3,5-triphenyl tetrazolium chloride reduction %, relative leaf water content and chlorophyll content was observed to be significantly mitigated in ABA-applied plants. A greater pollen viability, pollen germination, flower retention and pod set were noticed in ABA-treated plants compared with stressed plants. The seed yield showed considerable improvement in the plants treated with ABA relative to the stressed plants that was attributed to the increase in seed weight, greater number of single seeded pods and reduction in number of infertile pods. The oxidative damage measured as thiobarbituric acid-reactive substances was lesser in ABA-treated plants that was associated with greater activities of superoxide dismutase, catalase, ascorbate peroxidase, ascorbic acid, glutathione and proline in these plants. It was concluded that cold stress effects were partly overcome by ABA treatment because of the improvement in water status of the leaves as well as the reduction in oxidative damage.