High frequency plant regeneration of Cymbopogon martinii (Roxb.) Wats by somatic embryogenesis and organogenesis

Embryogenic callus cultures were obtained upon repeated sub-culture of non-embryogenic callus from nodal segments of Cymbopogon martinii (Roxb.) Wats. Murashige and Skoog's medium supplemented with 1mg/l 2,4-dichlorophenoxyacetic acid and 0.5 mg/l kinetin and Linsmaier and Skoog's medium supplemented with 2mg/l 2,4-dichlorophenoxyacetic acid and 0.4 mg/l kinetin were used as maintenance media for non-embryogenic and embryogenic cultures, respectively. Plant regeneration occurred through organogenesis in MS basal media containing 2 mg/l kinetin, 1 mg/l 6-benzylaminopurine, 0.2 mg/l biotin, 0.2 mg/l Ca-pantothonate and 0.1 mg/l napthalene acetic acid. Embryogenesis was induced in LS medium supplemented with 1 mg/l kinetin, 0.5 mg/l 6-benzylaminopurine and 0.1 mg/l 3-indole acetic acid. Plant regeneration at high frequency was recorded both through organogenesis and embryogenesis in different passages of long term callus cultures.Abbreviation MS Murashige and Skoog medium - LS Linsmair and Skoog medium - BAP 6-benzylaminopurine - kin kinetin - 2,4-D 2,4-Dichlorophenoxyacetic acid - IAA Indole-3-acetic acid - CH Casein hydrolysate - CaP calcium pantothonate - NAA napthalene acetic acid     

On the participation of chloride in bicarbonate-induced reversal of anion inhibition of photosystem II electron transport in spinach thylakoids

Inhibition of electron transport through photosystem II (PS II) by formate (HCO⁻₂) or nitrite (NO⁻₂) in the presence or absence of chloride ions was studied. The inhibition induced by HCO⁻₂ or NO⁻₂ is overcome by HCO⁻₃ more in the presence, than in the absence of Cl⁻. The data on electron transport are supported by chlorophyll a fluorescence measurements. In experiments. In experiments in which water oxidation was blocked. Cl⁻ was found to facilitate electron transport between bound quinone A (Q⁻_A) and the plastoquinone (PQ) pool. It can thus be concluded that in addition to the well known site of action of Cl⁻ on water oxidation, another site of Cl⁻ action is between Q⁻_A and the PQ pool.     

miRNA in Parkinson's disease: From pathogenesis to theranostic approaches

Parkinson's disease (PD) is an age associated neurological disorder which is specified by cardinal motor symptoms such as tremor, stiffness, bradykinesia, postural instability, and non-motor symptoms. Dopaminergic neurons degradation in substantia nigra region and aggregation of αSyn are the classic signs of molecular defects noticed in PD pathogenesis. The discovery of microRNAs (miRNA) predicted to have a pivotal part in various processes regarding regularizing the cellular functions. Studies on dysregulation of miRNA in PD pathogenesis has recently gained the concern where our review unravels the role of miRNA expression in PD and its necessity in clinical validation for therapeutic development in PD. Here, we discussed how miRNA associated with ageing process in PD through molecular mechanistic approach of miRNAs on sirtuins, tumor necrosis factor-alpha and interleukin-6, dopamine loss, oxidative stress and autophagic dysregulation. Further we have also conferred the expression of miRNAs affected by SNCA gene expression, neuronal differentiation and its therapeutic potential with PD. In conclusion, we suggest more rigorous studies should be conducted on understanding the mechanisms and functions of miRNA in PD which will eventually lead to discovery of novel and promising therapeutics for PD.     

Fish and macroinvertebrate assemblages reveal extensive degradation of the world's rivers

Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences are poorly quantified at the global scale. We evaluated the biological condition of rivers globally, including the largest proportion of countries from the Global South published to date. We gathered macroinvertebrate- and fish-based assessments from 72,275 and 37,676 sites, respectively, from 64 study regions across six continents and 45 nations. Because assessments were based on differing methods, different systems were consolidated into a 3-class system: Good, Impaired, or Severely Impaired, following common guidelines. The proportion of sites in each class by study area was calculated and each region was assigned a Köppen-Geiger climate type, Human Footprint score (addressing landscape alterations), Human Development Index (HDI) score (addressing social welfare), % rivers with good ambient water quality, % protected freshwater key biodiversity areas; and % of forest area net change rate. We found that 50% of macroinvertebrate sites and 42% of fish sites were in Good condition, whereas 21% and 29% were Severely Impaired, respectively. The poorest biological conditions occurred in Arid and Equatorial climates and the best conditions occurred in Snow climates. Severely Impaired conditions were associated (Pearson correlation coefficient) with higher HDI scores, poorer physico-chemical water quality, and lower proportions of protected freshwater areas. Good biological conditions were associated with good water quality and increased forested areas. It is essential to implement statutory bioassessment programs in Asian, African, and South American countries, and continue them in Oceania, Europe, and North America. There is a need to invest in assessments based on fish, as there is less information globally and fish were strong indicators of degradation. Our study highlights a need to increase the extent and number of protected river catchments, preserve and restore natural forested areas in the catchments, treat wastewater discharges, and improve river connectivity.     

Computerized analysis of the motility parameters of hamster spermatozoa during maturation

A computer-aided semen analysis system was used for the objective assessment of hamster spermatozoa during epididymal maturation. The caput epididymal spermatozoa were extremely sluggish, achieved very little progression, and the three velocity parameters, namely curvilinear velocity (VCL), progressive velocity (VSL), and path velocity (VAP), were low. These spermatozoa during progressive movement alternated between the linear shape and “U” shape or attained an “S” shape prior to changing to the “U”; shape. The corpus epididymal spermatozoa were faster, displayed greater VSL, VAP, and VCL compared to caput epididymal spermatozoa, and, during forward motility, attained “U,” “C,”; and (or) “?” shape as in the wriggling motility pattern. The proximal cauda epididymal spermatozoa were actively motile and VSL, VAP, and VCL in these spermatozoa were more than 10 times greater compared to the caput epididymal spermatozoa. The proximal cauda epididymal spermatozoa predominantly moved in circles and with time became slower and more circular in their trajectories and exhibited a reduction in LIN (linearity). The distal cauda epididymal spermatozoa were very similar to the proximal cauda epididymal spermatozoa with respect to their fast motility (VSL, VAP, and VCL are similar) and beat cross frequency (BCF), but showed larger values for STR (straightness) and LIN and moved along curved trajectories. The amplitude of lateral head displacement (ALH) was also considerably lower in the distal cauda epididymal spermatozoa compared to the proximal cauda epididymal spermatozoa. Thus, this study provides for the first time data related to seven motility parameters for caput and corpus epididymal spermatozoa of hamster. It also provides additional data with respect to VCL, LIN, BCF, and ALH for proximal and distal cauda epididymal spermatozoa of hamster. © 1994 Wiley-Liss, Inc.     

Evaluation of marking and tagging methods for genetic studies in carp

A variety of marking and tagging methods were tested on common carp (Cyprinus carpio L.) with the aim of identifying suitable methods for genetic studies in this and other species of carp. Elastomer and Alcian blue dye marking; Cold and Silver nitrate branding; Floy, Fingerling, Carlin disc and visible implant tags; and fin clipping were all tested on a range of sizes of common carp (from mean weights of 10–25 g up to 600–800 g). The branding and tagging methods tested did not give satisfactory retention rates. A combination of elastomer marking and fin clipping was then tested as a method for strain identification in a growth comparison trial on catla (Catla catla Hamilton) and found to be satisfactory for this purpose. Passive integrated transponders (PIT) tags were used to individually identify catla of wild or hatchery origin being grown for use as broodstock. These had almost 100% (98.8%) retention rates, but are expensive compared to most other tagging methods.     

Ferulic acid mediated changes in oxidative enzymes of maize seedlings: implications in growth

Maize (Zea mays L. cv. Ganga-5) seedlings were grown in the presence of ferulic acid (0.5 – 3.0 mM) for 8 d. Treatment with ferulic acid considerably decreased shoot and root length, increased the activity of peroxidase, catalase and indole-3-acetic acid (IAA) oxidase and decreased the activity of polyphenol oxidase. The increased activity of peroxidase correlated with pronounced increase in content of lignin and phenolic compounds     

Effect of prenatal exposure to diagnostic ultrasound on the development of mice.

Pregnant Swiss albino mice were exposed to diagnostic ultrasound (3.5 MHz, approximately 65 mW) for 10 min on Day 3.5 (preimplantation period), 6.5 (early organogenesis period), or 11.5 (late organogenesis period) of gestation. Sham-exposed controls were maintained for comparison. Exposed as well as control fetuses were dissected out on the 18th day of gestation, and changes in total mortality, body weight, body length, head length, brain weight, sex ratio, and microphthalmia were recorded. Exposure on Day 3.5 of gestation resulted in a small increase in the resorption rate and a significant reduction in fetal body weight. A low fetal weight and an increase in the number of growth-retarded fetuses were produced by exposure on Day 6.5 postcoitus. A statistically nonsignificant increase in the incidence of microphthalmia was induced in fetuses exposed on Day 6.5 or Day 11.5 of gestation. These results indicate that ultrasound may have some adverse effects on the mouse embryos depending on the developmental stage at which the exposure occurred.     

Lipids and lipoprotein profile in doxorubicin treated rats: influence of alpha-tocopherol administration

The effect of doxorubicin (DXR) on the levels of heart, liver and plasma lipids and plasma lipoproteins were studied in rats. Rats were treated with DXR (2.5 mg/kg body weight weekly for 8 weeks, iv) with or without alpha-tocopherol (alpha-TPL) (400 mg/kg body wt daily for 60 days) co-administration. DXR treated rats showed increase in plasma total cholesterol, triglycerides and phospholipids. The activities of lecithin cholesterol-acyl transferase and hepatic and extrahepatic lipoprotein lipase were lowered significantly with concomitant increase in liver and heart lipid peroxide levels in DXR treatment. HDL cholesterol level was found to be decreased significantly in DXR treated rats as a result of which there was an increase of LDLc/HDLc ratio. alpha-TPL coadministration brought back the enzyme activity to near normal and reduced the level of lipid peroxides. The lipid changes were minimum in rats treated with both alpha-TPL and DXR. This study suggests that the toxicity of DXR is reflected in lipids and lipoprotein profile.     

Development of Fern Sporangia: a Fluorescence Microscopy Study

The utility of fluorescence microscopy for studying development of fern spores is investigated. Changes in the fluorescence characteristics during the developmental stages of fern sporangia can be attributed to the changes in the chemical composition of the cell wall. Bright blue autofluorescence of the spores indicated the presence of sporopollenin. The sporan-gial walls and the spores autofluoresced yellow under blue light excitation. Fluorescence microscopy is a useful addition to light, scanning, and transmission electron microscopy because living specimens can be studied owing to their fluorescence properties.