Generation mean analyses for flowering and maturity in Indian mustard (Brassica junces (L.) Czern & Coss)

Summary Components of generation means were partitioned for days to flower initiation and maturity in three crosses of Indian mustard (Brassica juncea (L.) Czern and Coss) cultivars. A linked digenics model was adequate for flowering in cross II and maturity in Cross I. All three types of digenic interactions among the linked pairs of genes, additive X additive (i), additive X dominance (j) and dominance X dominance (1), contributed significantly in the inheritance of flowering in cross II and maturity in cross I. A complete association among the genes of greater effects in higher mean parent was detected for flowering in cross II and maturity in Cross I. Duplicate epistasis was evident for flowering in Crosses I and II and maturity in Crosses I and III.Inadequacy of all the fitted models for days to flowering in Cross III and maturity in Cross II indicated the presence of higher order interactions.Part of PhD (plant breeding) Thesis, submitted by senior author to GBPUAT, Pantnagar (Nainital) U.P., India (unpublished). Research paper No. 4262     

Plant regeneration via somatic embryogenesis in chickpea (Cicer arietinum L.)

Efficient plant regeneration via somatic embryogenesis has been developed in chickpea cultivar C235. Leaf explants, on MS medium supplemented with 1.25 mg/l 2,4-D and 0.25 mg/l kinetin, yielded somatic embryos with high efficiency during dark incubation. MS medium supplemented with B₅ vitamins, 0.125 mg/l IBA and 2 mg/l BAP was found suitable for embryo maturation. The well formed embryos germinated into plantlets on basal B₅ medium supplemented with 0.25 mg/l BAP. Further development into healthy plantlets was obtained on basal B₅ medium. Hardened plantlets produced normal, fertile plants upon transfer to soil.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BAP 6-Benzyl-aminopurine - IAA IndoIe-3-acetic acid - IBA Indole-3-butyric acid - NAA 1-Naphthalene acetic acid - Kinetin 6-furfuryl aminopurine - Zeatin 6-(4-hydroxy-3-methylbut-2-enylamino)-purine     

Effect of soil moisture stress on legume-rhizobium symbiosis in soybeans

Summary In a pot culture experiment, the influence of soil moisture stress at different physiological stages of soybean, cv. Hark, on nodulation, symbiosis and nitrogen accumulation was studied. Moisture stress reduced leghemoglobin content of root nodules and nitrogen uptake by plants. It had no effect on number of bacteroids. Stress at mid bloom and rapid pod filling stages reduced yield and seed protein content. However, these parameters were not affected by stress at nodule initiation and early flowering stages, though, flower initiation and maturity of the plant were delayed. Moisture stress at any stage did not alter nitrogen status of roots.     

Clinical Significance of Circulating Serum Levels of sCD95 and TNF-α in Cytoprotection of Cervical Cancer

Background:This study correlates the serum levels of sCD95 & TNF-α with a simple cell-based assay to evaluate the capacity of the serum sample to induce apoptosis in Jurkat cells. Interlinking of these parameters can be explored to design a minimum invasive diagnostic strategy for cervical cancer (CC).Methods:Sera samples were assessed to induce apoptosis in Jurkat cells through FACS. Serum levels of sCD95 and TNF-α were measured by ELISA. JNK phosphorylation was evaluated in sera incubated Jurkat cells. Data was scrutinized through statistical analysis.Results:Significantly higher serum levels of sCD95 and lower TNF-α levels were observed in CC patients; their sera samples inhibited induction of apoptosis in Jurkat cells through reduced JNK phosphorylation. Statistical analysis linked these three parameters for the early screening of CC.Conclusion:Distinct sera levels of sCD95 & TNF-α in CC patients showed an anti-apoptotic effect, which can be considered for early detection of CC.Key Words: Apoptosis, sCD95, Jurkat Cells, Tumor Necrosis Factor-alpha, Uterine Cervical Neoplasms     

A medium-throughput functional assay of KCNQ2 potassium channels using rubidium efflux and atomic absorption spectrometry

Heterologous expression of KCNQ2 (Kv7.2) results in the formation of a slowly activating, noninactivating, voltage-gated potassium channel. Using a cell line that stably expresses KCNQ2, we developed a rubidium flux assay to measure the functional activity and pharmacological modulation of this ion channel. Rubidium flux was performed in a 96-well microtiter plate format; rubidium was quantified using an automated atomic absorption spectrometer to enable screening of 1000 data points/day. Cells accumulated rubidium at 37 degrees C in a monoexponential manner with t(1/2)=40min. Treating cells with elevated extracellular potassium caused membrane depolarization and stimulation of rubidium efflux through KCNQ2. The rate of rubidium efflux increased with increasing extracellular potassium: the t(1/2) at 50mM potassium was 5.1 min. Potassium-stimulated efflux was potentiated by the anticonvulsant drug retigabine (EC(50)=0.5 microM). Both potassium-induced and retigabine-facilitated efflux were blocked by TEA (IC(50)s=0.4 and 0.3mM, respectively) and the neurotransmitter release enhancers and putative cognition enhancers linopirdine (IC(50)s=2.3 and 7.1 microM, respectively) and XE991 (IC(50)s=0.3 and 0.9 microM, respectively). Screening a collection of ion channel modulators revealed additional inhibitors including clofilium (IC(50) = 27 microM). These studies extend the pharmacological profile of KCNQ2 and demonstrate the feasibility of using this assay system to rapidly screen for compounds that modulate the function of KCNQ2.     

Effects of cardiogenic edema fluid on ion and fluid transport in the adult lung

We have previously shown that cardiogenic pulmonary edema fluid (EF) increases Na(+) and fluid transport by fetal distal lung epithelia (FDLE) (Rafii B, Gillie DJ, Sulowski C, Hannam V, Cheung T, Otulakowski G, Barker PM and O'Brodovich H. J Physiol 544: 537-548, 2002). We now report the effect of EF on Na(+) and fluid transport by the adult lung. We first studied primary cultures of adult type II (ATII) epithelium and found that overnight exposure to EF increased Na(+) transport, and this effect was mainly due to factors other than catecholamines. Plasma did not stimulate Na(+) transport in ATII. Purification of EF demonstrated that at least some agent(s) responsible for the amiloride-insensitive component resided within the globulin fraction. ATII exposed to globulins demonstrated a conversion of amiloride-sensitive short-circuit current (I(sc)) to amiloride-insensitive I(sc) with no increase in total I(sc). Patch-clamp studies showed that ATII exposed to EF for 18 h had increased the number of highly selective Na(+) channels in their apical membrane. In situ acute exposure to EF increased the open probability of Na(+)-permeant ion channels in ATII within rat lung slices. EF did increase, by amiloride-sensitive pathways, the alveolar fluid clearance from the lungs of adult rats. We conclude that cardiogenic EF increases Na(+) transport by adult lung epithelia in primary cell culture, in situ and in vivo.     

Degradation of ferulic acid by a white rot fungus <Emphasis Type="Italic">Schizophyllum commune</Emphasis>

Summary A ubiquitous white rot fungus Schizophyllum commune was used for the first time to study the degradation of ferulic acid. Vanillic acid was observed as one of the major products of ferulic acid catabolism, with vanillin formed as an intermediate. Almost 99.9% ferulic acid with a initial concentration of 5 mM was consumed by this fungus after 16 days of incubation at 37 °C.     

Transforming Growth Factor-��-activated Kinase 1 Is an Essential Regulator of Myogenic Differentiation

Satellite cells/myoblasts account for the majority of muscle regenerative potential in response to injury and muscular adaptation to exercise. Although the ability to influence this process would provide valuable benefits for treating a variety of patients suffering from muscle loss, the regulatory mechanisms of myogenesis are not completely understood. We have tested the hypothesis that transforming growth factor-β-activated kinase 1 (TAK1) is an important regulator of skeletal muscle formation. TAK1 is expressed in proliferating C2C12 myoblasts, and its levels are reduced upon differentiation of myoblasts into myotubes. In vivo, TAK1 is predominantly expressed in developing skeletal muscle of young mice. However, the expression of TAK1 was significantly up-regulated in regenerating skeletal muscle of adult mice. Overexpression of a dominant negative mutant of TAK1 or knockdown of TAK1 inhibited the proliferation and differentiation of C2C12 myoblasts. TAK1 was required for the expression of myogenic regulatory factors in differentiating myoblasts. Genetic ablation of TAK1 also inhibited the MyoD-driven transformation of mouse embryonic fibroblasts into myotubes. Inhibition of TAK1 suppressed the differentiation-associated activation of p38 mitogen-activated protein kinase (MAPK) and Akt kinase. Overexpression of a constitutively active mutant of MAPK kinase 6 (MKK6, an upstream activator of p38 MAPK) but not constitutive active Akt restored the myogenic differentiation in TAK1-deficient mouse embryonic fibroblasts. Insulin growth factor 1-induced myogenic differentiation was also found to involve TAK1. Collectively, our results suggest that TAK1 is an important upstream regulator of skeletal muscle cell differentiation.     

The TWEAK–Fn14 system is a critical regulator of denervation-induced skeletal muscle atrophy in mice

Skeletal muscle atrophy occurs in a variety of clinical settings, including cachexia, disuse, and denervation. Inflammatory cytokines have been shown to be mediators of cancer cachexia; however, the role of cytokines in denervation- and immobilization-induced skeletal muscle loss remains unknown. In this study, we demonstrate that a single cytokine, TNF-like weak inducer of apoptosis (TWEAK), mediates skeletal muscle atrophy that occurs under denervation conditions. Transgenic expression of TWEAK induces atrophy, fibrosis, fiber-type switching, and the degradation of muscle proteins. Importantly, genetic ablation of TWEAK decreases the loss of muscle proteins and spared fiber cross-sectional area, muscle mass, and strength after denervation. Expression of the TWEAK receptor Fn14 (fibroblast growth factor–inducible receptor 14) and not the cytokine is significantly increased in muscle upon denervation, demonstrating an unexpected inside-out signaling pathway; the receptor up-regulation allows for TWEAK activation of nuclear factor κB, causing an increase in the expression of the E3 ubiquitin ligase MuRF1. This study reveals a novel mediator of skeletal muscle atrophy and indicates that the TWEAK–Fn14 system is an important target for preventing skeletal muscle wasting.