The annual reproductive cycle and sex inversion of the Picnic seabream,Acanthopagrus berda (Forsskål 1775) from Indian waters: Histological and morphometric description

The annual reproductive cycle of picnic seabream, Acanthopagrus berda (Forsskål, 1775), one of the potential aquaculture candidate from estuarine waters of Calicut, Kerala (India) was studied. Based on the morphological and histological studies, the ovotestes of A. berda were classified as active male, active female, inactive male, inactive female, transitional and undifferentiated. Histological observation of transitional gonads showed signs of degeneration in the testicular lobe, proliferation of connective tissue and empty sperm ducts indicating protandrous hermaphroditism in A. berda. Ovary was classified into seven maturity stages (virgin, developing virgin, developing, maturing, mature, running, spent) and testis into five maturity stages (resting, maturing, mature, running, spent). Gonadal development in A. berda indicated resting phase (February–July), pre‐spawning phase (March–August) and spawning phase (August–December). Inactive (24.6%) and active males (21.6%) were observed as dominant in smaller length classes (140–250 mm TL), whereas inactive (18%) and active females (51%) were observed as dominant in larger length classes (251–450 mm TL). Few primary females (28.1%) were observed in smaller (below 250 mm TL) and few primary males (28.5%) were observed in larger length classes (above 250 mm TL). From the present study, it can be concluded that in A. berda, most of the individuals function first as males and then change sex to female, but few continue to function as either male or female throughout their lifespan indicating digynous protandrous hermaphroditism.     

Identification of genomic regions linked to blast (Pyricularia grisea) resistance in pearl millet

Blast disease causes serious economic yield losses in pearl millet. Identification and introgression of genomic regions associated with blast resistance can help to develop resistant cultivars to minimize yield losses incurred from blast outbreaks. In this study, 384 advanced pearl millet genotypes were screened against six blast pathotype-isolates (major pearl millet growing agro-ecologies of India), namely, Pg 45, Pg 118, Pg 138, Pg 186, Pg 204 and Pg 232. Analysis of variance showed significant (P < .001) variation among genotypes for blast reaction (susceptible to resistance). ICMR 08111 and ICMR 10888 genotypes showed resistance to all six blast pathotypes. A genome-wide association study performed with 264,241 single nucleotide polymorphic markers could successfully identify 15 SNPs (P = 1.26 × 10⁻⁷ to 9.22 × 10⁻¹²) underlying the genomic regions governing blast-resistance across five different chromosomes. The SNPs reported had a significant association in at least two of the three models tested (GLM, MLM and Farm CPU). These SNPs can be used in pearl millet-resistant breeding programmes after their function has been validated across different genetic backgrounds.     

Effect of dietary rosemary extract on cell-mediated immunity of young rats

The impact of rosemary extract on splenic mononuclear cell proliferation was determined. Weanling male Sprague-Dawley rats were fed diets containing 0, 100, 200 or 400 ppm rosemary extract or 400 ppm butylated hydroxytoluene (BHT) in combinatiion with 10 or 20% casein enriched diets for 8 weeks. Splenic mononuclear cells were isolated from these animals and mitogenic response to Concanavalin A (Con A), Phytohemagglutinin (PHA) and lipopolysaccharide was determined. Con A and PHA-stimulated proliferation of spleen cells from rats fed 10% casein and 200 ppm rosemary extract was significantly higher than that of cells from the corresponding control animals. However, other levels of rosemary at 10% dietary casein or rosemary at any concentration fed along with 20% dietary casein had no impact on the mitogenic stimulation of splenic mononuclear cells. Thus, these results suggest that the use of rosemary might not have a generalized immunoenhancing effect, and will probably be effective in some stressed conditions, such as protein or antioxidant deficiency.     

Antitussive effect of Asparagus racemosus root against sulfur dioxide-induced cough in mice

The methanol extract of Asparagus racemosus root (200 and 400 mg/kg, p.o.) showed significant antitussive activity on sulfur dioxide-induced cough in mice, the cough inhibition (40.0 and 58.5%, respectively) being comparable to that of 10–20 mg/kg of codeine phosphate (36.0 and 55.4%, respectively).     

Nutritional potential ofVigna minima (Roxb.) Ohwi and Ohashi:

Quantitative variation in different fractions of seed proteins and their amino acid levels in populations ofVigna minima (Roxb.) Ohwi and Ohashi and inV. umbellata cv. IC 1568 — the rice bean — were investigated. Globulin I fraction, together with globulin II, constitutes 38 to 54 per cent of the total seed protein. The alkali soluble (glutelin) fraction is the second largest fraction. Both these fractions show broad range of variation, suggesting a broad genetic base. The profiles are population specific; the coastal population, which contains higher seed protein also possesses maximum levels of globulin I and glutelin fraction suggesting its potentiality for breeding lines with high protein content, high nutritive value, and salt tolerance. Protein content is positively correlated with globulin I and glutelin fractions, which are in turn positively correlated with each other. The amino acid profiles are specific not only to the fractions but also to the populations. The range of variation in the levels of all amino acids in different fractions is broad suggesting substantial genetic diversity. The average levels of lysine and sulphur amino acids are high in globulin I and glutelin fractions.     

Vegetative growth and nutritional status as influenced by auxins and gibberellic acid,and their effect on fruit yield in lemon

Application of 2,4-D and 2,4,5-T at concentrations ranging from 5 to 20 mg l^?1 to 5-year-old ‘Pant Lemon-1’ (Citrus limon Burm) trees reduced the vegetative growth in terms of height, spread, shoot length, number and size of the leaves in the autumn flush. Various NAA treatments (5–20 mg l^?1), however, enhanced growth, but not to the extent that was observed after GA₃ treatments. Application of GA₃ at 10–40 mg l^?1 significantly enhanced all aspects of growth, and the effects were most pronounced at 20 and 40 mg l^?1. Nutritional status of the leaves showed a slight variation in relation to vegetative growth under various treatments.Some 2,4-D- and 2,4,5-T-treatments increased the fruit yield over the control, which could suggest mobilization of foods even at the expense of reduced vegetative growth. On the other hand, NAA, particularly at 10 mg l^?1, increased both vegetative growth and yield, suggesting that the transport of the photosynthates from the leaves to the fruits was not at the expense of new growth extension. Due to excessive growth enhancement under higher concentrations of GA₃ (20 and 40 mg l^?1), comparatively fewer nutrients were translocated to the fruit “sinks”, thereby resulting in a non-significant decrease in yield.     

Characterization of a phytotoxic glycoprotein produced byPhoma eupyrena — A pathogen on water lettuce

Phoma eupyrena, the causal agent of leaf blight disease of water lettuce, when purified by affinity and ion exchange chromatography produced an extracellular glycoprotein (Pe 65) in concentrations of ∼ 8 μg ml⁻¹ in the stationary culture. Coomassie-blue stained SDS-PAGE analysis of culture filtrates and purified Pe 65 showed its molecular mass to be 65 kDa. The blighting and necrosis of leaf tissues were observed within 4–6 days when 1–5 μg of Pe 65 was injected into the mesophyll of water lettuce. These symptoms closely resembled those caused by foliar inoculation with the pathogen. Recognition of Pe 65 by N-glycosidase F treatment and by polyclonal antibodies raised in rabbit against the whole glycoprotein, indicated that the protein is a highly glycosylated protein (50% carbohydrate) and that it is strongly enclosed by the antigenic glycosidic moiety. http://www.phytoparasitica.org posting May 6, 2003.     

Ration restriction,compensatory growth and pituitary growth hormone gene expression in Labeo rohita

An experiment to investigate the compensatory growth (CG) response of Labeo rohita was conducted in two phases: a first phase (6 weeks) in which triplicate groups of fish were subjected to feed restriction (5, 25, 50 and 75 % of satiation) or satiation feeding (control) and a second phase (6 weeks) of satiation feeding for all treatment groups. CG in body weight occurred in groups which were under moderate feed restriction (50–75 % of satiation) under phase 1, but more severe feed restrictions resulted in lower weight gain. Improved feed conversion ratio (FCR) (1.6 ± 0.05 and 1.9 ± 0.03) relative to control (2.1 ± 0.06) was observed in the fish that displayed CG following moderate feed restriction (50–75 % of satiation). At the end of the experiment, body moisture, lipid and protein content were not significantly different between moderately restricted fish and the control. After the first phase, there was no significant difference in the expression of pituitary growth hormone (GH) gene between groups, but at the end of the experiment, significantly lower GH expression was observed in the fish subjected to a restriction of 25 and 50 % of satiation during phase 1. Exploiting the ability of fishes to undergo CG in terms of weight gain and improved FCR without major changes in body composition can be considered as an effective management practice.     

Monoclonal antibody-based immunodot for evaluating serum immunoglobulin levels in rohu (Labeo rohita)

Immune response in rohu treated with an immunomodulator is usually evaluated employing either non-specific immune parameters or traditional antibody-based tools. In the present study, a monoclonal antibody-based immunodot has been developed for evaluating antibody titre in rohu as a preliminary tool to ensure antibody response due to the effect of an immunomodulator, which can be used for routine field level analysis. The immunodot was sensitive enough to determine rohu immunoglobulin up to 15 μg/ml. Application of the immunodot for evaluating enhancement in immune response could be successfully demonstrated in probiotic fed rohu.     

Endocrine disruption by Bisphenol A,polychlorinated biphenyls and polybrominated diphenyl ether,in zebra fish (<Emphasis Type="Italic">Danio rerio</Emphasis>) model: an in silico approach

Endocrine disrupting chemicals may induce adverse health effects in humans and wildlife. Recent studies demonstrate that endocrine disrupting chemicals like Bisphenol A (BPA), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ether (PBDE) affect the reproductive characters shared by wide range of creatures including fish. An attempt was made to evaluate the toxicity of these chemicals on the vitellogenin protein of zebra fish (Danio rerio) using in silico approach. The protein structure of zebra fish vitellogenin was predicted using homology modelling, and the stereochemical quality of the model was validated by Ramachandran plot. The 3-D structure of vitellogenin was docked with the aforementioned chemicals that have demonstrated endocrine-disrupting activity. The pair-wise alignments between vitellogenin with phosvitin, lipovitellin-2 and YGP40 obtained by CLUSTALW alignment suggest that the vitellogenin contained lipovitellin-2- phosvitin- and YGP40-related amino acid sequences. Based on the prediction of CASTp and CLUSTALW, BPA and PCB predominantly interacted with lipovitellin-2 site of the protein, while PBDE interacts predominantly with the YGP40 site of the vitellogenin protein. The results indicate that the endocrine-disrupting chemicals (BPA, PCB and PBDE) dock with the vitellogenin cleavage sites lipovitellin-2 and YGP40 that play a crucial role in lipid–protein complex formation in the egg yolk. We hypothesize that these chemicals could potentially impair the egg yolk formation and eventually impact the zebra fish population which occupies an important niche among testing models used in drug discovery and related toxicity studies.