Single genetic stock of kawakawa Euthynnus affinis (Cantor, 1849) along the Indian coast inferred from sequence analyses of mitochondrial DNA D-loop region

Kawakawa Euthynnus affinis is an epipelagic migratory tuna species, widely distributed in the tropical and subtropical waters of the Indo-Pacific region. Kawakawa constitutes the largest tuna fishery in the Indian waters. In the present study, genetic variation was assessed using sequence analyses of Mitochondrial DNA (mtDNA) D-loop region. A 500 bp segment of D-loop region was sequenced in 400 samples collected from eight localities (Veraval (VE), Ratnagiri (RA), Kochi (KO), Kavaratti (KA), Port-Blair (PB), Tuticorin (TU), Pondicherry (PO), and Vizag (VI)) along the Indian coast. Analysis of molecular variance of mtDNA data revealed no significant genetic differentiation among sites the (Φ _ST ?=?0.0028, P?=?0.20723) indicating a single population along the Indian coast. Phylogenetic analysis revealed no obvious phylogeographic pattern separating the eight samples of kawakawa. However, the genealogical relationships demonstrated that mtDNA D-loop sequences belong to two different clades (clade I and clade II). Clade I is the major clade which consists of more than 98?% specimens from each regional population while clade II has individuals from only three populations (VE, PO, and VI). Results of genetic analyses of the present study support a single stock management of kawakawa along the Indian coast.     

A Simple Construction Procedure for Eesolvable Incomplete Block Designs for any Number of Treatments

A simple, straightforward procedure, which requires no special tables or generators, is presented for constructing resolvable incomplete block designs for v=pk, v=p²k, …, treatments, for k≥p, in incomplete blocks of size k. Also, it is shown, how to obtain incomplete block designs for any v in blocks of size k and k+1. The procedure allows construction of balanced incomplete block designs for p = k a prime number. For p = n not a prime number, incomplete block designs can be obtained by the procedure, but are not balanced. However, for p_s being the smallest prime factor of n, p_s + 1 for v = n², p_s²+ p_s + 1 for v = n³, …, arrangements can be obtained for which the occurrence of any treatment pair in the blocks is either zero or one. This is called a zero-one concurrence design. Procedures are described for obtaining additional zero-one concurrence arrangements. It is shown that the efficiency of these designs is maximum. Both intra-block and inter-block analyses are described.     

Effect of Age and Rehydration on Greening of Wheat Leaves

Photosynthetic pigment synthesis was enhanced upto 15 day withincreasing age of etiolated wheat (Triticum aestivum L. cv.Sonalika) seedlings. The adverse effect of water stress on chlorophyll(Chl) synthesis was observed even after complete rehydrationof the seedlings. Younger seedlings were more prone to stressthan the older ones. The older rehydrated seedlings showed stressrecovery ability in the post lag phase of greening. (Received August 15, 1985; Accepted October 21, 1986)     

Effect of Different Physical Factors on efficacy of Thevetia Peruviana leaf extract and bio-formulations

Plant extract possess various secondary metabolites which are antifungal in nature and can be used as a safer alternative to the synthetic fungicides. As we all know that the chemical fungicides are harmful not only for humans but also for animals, other vegetation and for complete ecosystem. To overcome this problem, we have to focused on another alternative which are biologically libel and nonhazardous also. In the present study, herbal formulation was prepared in various combination ratios with Thevetia peruviana leaf extracts, cow dung and neem oil cake. The major aim of this short study is to check the stability of the said plant extracts and prepared herbal formulation on various physical factors like heat, temperature, pH, sunlight and storage etc. The extracts and herbal formulations were exposed to varying conditions of the parameters selected for a precise time period, and then observing the effect as a function of change in the crude extract activity, herbal formulation activity and change minimum inhibitory concentration of plant extract against the Alternaria solani. Control set of MIC, and extract free medium were maintained for comparison in each set of experiment against Alternaria solani. Results suggested that efficacy of leaf extracts and different formulations was not affected by wet heat up to 100 °C while slight reduction in antifungal activity of the plant extract and herbal formulations were observed with dry heat at 100 °C. In addition, slight reduction in activity of extract and herbal formulations was observed with change in pH. However antifungal activity of plant extract as well as herbal formulations, remain unaffected at alkaline pH (pH 9) and neutral pH (pH7). Storage for 6 and 12 months had no negative effect on extract and herbal formulation efficacy and the antifungal activity was observed similar to freshly prepared extract activity. The present study concluded that the plant disease or plant pathogens can be controlled by plant extract and plant based bioformulations by increasing the shelf life with some little changes in the physical parameters such as light, temperature, pH and storage.     

Development of a novel pharmacophore model to screen specific inhibitors for the serine-threonine protein phosphatase calcineurin

Calcineurin (CaN) is a calcium/calmodulin-dependent serine/threonine phosphatase with a crucial role in cellular homeostasis. It is also the target of the Food and Drug Administration (FDA) approved immunosuppressant drugs FK506 and cyclosporine A. Recent work from our group and others indicated that an uncontrolled increase in CaN activity causes synaptic dysfunction and neuronal death in various models of neurodegenerative diseases associated with calcium dysregulation. Furthermore, pharmacological normalization of CaN activity can prevent disease progression in animal models. However, none of the FDA-approved CaN inhibitors bind CaN directly, leading to adverse side effects. The development of direct CaN inhibitors is required to reduce off-target effects, but its highly conserved active site and similar mechanism of action with other protein serine/threonine phosphatases impose a significant challenge. In this work, we developed a novel pharmacophore model to screen for CaN-specific inhibitors. Then, we performed a virtual screen for molecules having the pharmacophore model. We also show that the molecules identified in this screen can inhibit CaN with a low micromolar IC₅₀. Interestingly, the inhibitors identified from the screen do not inhibit phosphoprotein phosphatase 2A, a member of the serine/threonine phosphatase family that shares 43% sequence identity with the CaN active site. The pharmacophore model that we developed and validated in this work may help to accelerate the development of specific CaN inhibitors.     

Waterlogging-induced increase in sugar mobilization, fermentation, and related gene expression in the roots of mung bean (Vigna radiata)

The objective of this study was to examine the role of root carbohydrate levels and metabolism in the waterlogging tolerance of contrasting mung bean genotypes. An experiment was conducted with two cultivated mung bean (Vigna radiata) genotypes viz., T44 (tolerant) and Pusa Baisakhi (PB) (susceptible), and a wild Vigna species Vigna luteola under pot-culture to study the physiological and molecular mechanism of waterlogging tolerance. Waterlogging resulted in decrease in relative water content (RWC), membrane stability index (MSI) in root and leaf tissues, and chlorophyll (Chl) content in leaves, while the Chl a/b ratio increased. Waterlogging-induced decline in RWC, MSI, Chl and increase in Chl a/b ratio was greater in PB than V. luteola and T44. Waterlogging caused decline in total and non-reducing sugars in all the genotypes and reducing sugars in PB, while the content of reducing sugar increased in V. luteola and T44. The pattern of variation in reducing sugar content in the 3 genotypes was parallel to sucrose synthase (SS) activity. V. luteola and T44 also showed fewer declines in total and non-reducing sugars and greater increase in reducing sugar and SS activity than PB. Activity of alcohol dehydrogenase (ADH) increased up to 8d of waterlogging in V. luteola and T44, while in PB a marginal increase was observed only up to 4d of treatment. Gene expression studies done by RT-PCR in 24h waterlogged plants showed enhanced expression of ADH and SS in the roots of V. luteola and T44, while in PB there was no change in expression level in control or treated plants. PCR band products were cloned and sequenced, and partial cDNAs of 531, 626, and 667; 702, 736, and 744bp of SS and ADH, respectively were obtained. The partial cDNA sequences of cloned SS genes showed 93-100 homologies among different genotypes and with D10266, while in case of ADH the similarity was in the range of 97-100% amongst each other and with Z23170. The results suggest that the availability of sufficient sugar reserve in the roots, activity of SS to provide reducing sugars for glycolytic activity and ADH for the recycling of NADH, and for the continuation of glycolysis, could be one of the important mechanisms of waterlogging tolerance of V. radiata genotype T44 and wild species V. luteola. This was reflected in better RWC and Chl content in leaves, and membrane stability of leaf and root tissue in V. luteola and T44.     

DNA-PKcs and ATM co-regulate DNA double-strand break repair

DNA double-strand breaks (DSBs) are repaired by nonhomologous end-joining (NHEJ) and homologous recombination (HR). The NHEJ/HR decision is under complex regulation and involves DNA-dependent protein kinase (DNA-PKcs). HR is elevated in DNA-PKcs null cells, but suppressed by DNA-PKcs kinase inhibitors, suggesting that kinase-inactive DNA-PKcs (DNA-PKcs-KR) would suppress HR. Here we use a direct repeat assay to monitor HR repair of DSBs induced by I-SceI nuclease. Surprisingly, DSB-induced HR in DNA-PKcs-KR cells was 2- to 3-fold above the elevated HR level of DNA-PKcs null cells, and ～4- to 7-fold above cells expressing wild-type DNA-PKcs. The hyperrecombination in DNA-PKcs-KR cells compared to DNA-PKcs null cells was also apparent as increased resistance to DNA crosslinks induced by mitomycin C. ATM phosphorylates many HR proteins, and ATM is expressed at a low level in cells lacking DNA-PKcs, but restored to wild-type level in cells expressing DNA-PKcs-KR. Several clusters of phosphorylation sites in DNA-PKcs, including the T2609 cluster, which is phosphorylated by DNA-PKcs and ATM, regulate access of repair factors to broken ends. Our results indicate that ATM-dependent phosphorylation of DNA-PKcs-KR contributes to the hyperrecombination phenotype. Interestingly, DNA-PKcs null cells showed more persistent ionizing radiation-induced RAD51 foci (but lower HR levels) compared to DNA-PKcs-KR cells, consistent with HR completion requiring RAD51 turnover. ATM may promote RAD51 turnover, suggesting a second (not mutually exclusive) mechanism by which restored ATM contributes to hyperrecombination in DNA-PKcs-KR cells. We propose a model in which DNA-PKcs and ATM coordinately regulate DSB repair by NHEJ and HR.