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V. Sheeba V. Kumar Sharma M.K. Chandrashekaran A. Joshi 《Biological Rhythm Research》2013,44(4):424-433
Egg to eclosion development time and survivorship were assayed on four laboratory populations of Drosophila melanogaster that had been reared for over 600 generations in continuous light (LL) and constant temperature. The assays were performed in three environments: continuous light (LL), periodically varying light/dark cycles (LD 12:12 hr), and continuous darkness (DD). Development time in LL was significantly less than that in LD, which, in turn, was significantly less than that in DD, whereas survivorship did not differ significantly among the three treatments. The results indicate that individuals from Drosophila populations routinely maintained in LL do not suffer any deleterious effects of LL treatment on pre-adult fitness. Other studies on these populations have shown that free-running period (t) of the eclosion rhythm in DD is greater than that in LD. Our results are, thus, also consistent with the notion that development time may be a function of the free-running period. 相似文献
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A. M. Abd El-Moghny H. B. Santosh K. P. Raghavendra J. A. Sheeba S. B. Singh K. R. Kranthi 《Journal of plant biochemistry and biotechnology.》2017,26(3):366-370
Genetic diversity is an essential input for any plant breeding programme. To assess the genetic divergence among the newly identified drought tolerant lines and elite cotton genotypes including popular varieties, a total of 51 distinctly polymorphic markers were identified after screening 142 genome-wide SSR markers. The identified polymorphic markers detected a total of 140 alleles with a mean of 2.75 alleles per loci and average polymorphism information content of 0.45. Jaccard coefficient based dissimilarity index between the genotypes ranged from 0.18 to 0.82 indicating existence of wide variation between and within the drought tolerant and susceptible genotypes at the DNA level. Cluster and factorial analyses have provided the structure of genetic diversity present and clearly distinguished the drought tolerant and susceptible cotton genotypes. Clustering pattern was in congruence with the source or pedigree of genotypes. The information generated in the present study on genetic divergence among genotypes having differential response to drought will help in selection of suitable lines as parents for developing drought tolerant cultivars in cotton. The polymorphic markers and diverse lines identified in the study will be of immense utility in molecular mapping and marker assisted breeding to achieve drought tolerance in cotton. 相似文献
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Lucy Wentworth Justin V. Meyers Sheeba Alam Andrew J. Russ M. Suresh Clifford S. Cho 《Cancer immunology, immunotherapy : CII》2013,62(1):149-159
We have previously observed that in vivo exposure to growing melanoma tumors fundamentally alters activated T cell homeostasis by suppressing the ability of naïve T cells to undergo antigen-driven proliferative expansion. We hypothesized that exposure of T cells in later stages of differentiation to melanoma would have similar suppressive consequences. C57BL/6 mice were inoculated with media or syngeneic B16F10 melanoma tumors 8 or 60 days after infection with lymphocytic choriomeningitis virus (LCMV), and splenic populations of LCMV-specific T cells were quantified using flow cytometry 18 days after tumor inoculation. Inoculation with melanoma on post-infection day 8 potentiated the contraction of previously activated T cells. This enhanced contraction was associated with increased apoptotic susceptibility among T cells from tumor-bearing mice. In contrast, inoculation with melanoma on post-infection day 60 did not affect the ability of previously established memory T cells to maintain themselves in stable numbers. In addition, the ability of previously established memory T cells to respond to LCMV challenge was unaffected by melanoma. Following adoptive transfer into melanoma-bearing mice, tumor-specific memory T cells were significantly more effective at controlling melanoma growth than equivalent numbers of tumor-specific effector T cells. These observations suggest that memory T cells are uniquely resistant to suppressive influences exerted by melanoma on activated T cell homeostasis; these findings may have implications for T cell–based cancer immunotherapy. 相似文献
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Method for enhancing solubility of the expressed recombinant proteins in Escherichia coli 总被引:1,自引:0,他引:1
Ghosh S Rasheedi S Rahim SS Banerjee S Choudhary RK Chakhaiyar P Ehtesham NZ Mukhopadhyay S Hasnain SE 《BioTechniques》2004,37(3):418, 420, 422-418, 420, 423
The production of correctly folded protein in Escherichia coli is often challenging because of aggregation of the overexpressed protein into inclusion bodies. Although a number of general and protein-specific techniques are available, their effectiveness varies widely. We report a novel method for enhancing the solubility of overexpressed proteins. Presence of a dipeptide, glycylglycine, in the range of 100 mM to 1 M in the medium was found to significantly enhance the solubility (up to 170-fold) of the expressed proteins. The method has been validated using mycobacterial proteins, resulting in improved solubilization, which were otherwise difficult to express as soluble proteins in E. coli. This method can also be used to enhance the solubility of other heterologous recombinant proteins expressed in a bacterial system. 相似文献
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Glycosylation is one of the major naturally occurring covalent modifications of proteins. We have used stem bromelain, a thiol protease with a single, N-glycosylated polypeptide chain as a model to investigate the role of glycosylation of proteins. Periodate oxidation was used to obtain the deglycosylated form of the enzyme. Denaturation studies in the presence of guanidine hydrochloride (Gn·HCl) were performed using fluorescence and circular dichroism spectroscopy. The glycosylated stem bromelain was found to be stabilized by 1.9 kcal/mol as compared to the deglycosylated one. At a given concentration of denaturant, the fraction of denatured protein was higher in the case of deglycosylated stem bromelain. In short, deglycosylated bromelain showed more susceptibility towards guanidine hydrochloride denaturation, indicating the contribution of the carbohydrate part of the glycoprotein to the stability of the enzyme. 相似文献
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Shubha Priyamvada Sara A. Khan Md.Wasim Khan Sheeba Khan Neelam Farooq Farah Khan A.N.K. Yusufi 《Prostaglandins, leukotrienes, and essential fatty acids》2010,82(1):35-44
Human and animal exposure demonstrates that uranium is nephrotoxic. However, attempts to reduce it were not found suitable for clinical use. Dietary fish oil (FO) enriched in ω-3 fatty acids reduces the severity of cardiovascular and renal diseases. Present study investigates the protective effect of FO on uranyl nitrate (UN)-induced renal damage. Rats prefed with experimental diets for 15 days, given single nephrotoxic dose of UN (0.5 mg/kg body weight) intraperitoneally. After 5 d of UN treatment, serum/urine parameters, enzymes of carbohydrate metabolism, brush border membrane (BBM), oxidative stress and phosphate transport were analyzed in rat kidney. UN nephrotoxicity was characterized by increased serum creatinine and blood urea nitrogen. UN increased the activity of lactate dehydrogenase and NADP-malic enzyme whereas decreased malate, isocitrate and glucose-6-phophate dehydrogenases; glucose-6-phophatase, fructose-1, 6-bisphosphatase and BBM enzyme activities. UN caused oxidant/antioxidant imbalances as reflected by increased lipid peroxidation, activities of superoxide dismutase, glutathione peroxidase and decreased catalase activity. Feeding FO alone increased activities of enzymes of glucose metabolism, BBM, oxidative stress and Pi transport. UN-elicited alterations were prevented by FO feeding. However, corn oil had no such effects and was not similarly effective. In conclusion, FO appears to protect against UN-induced nephrotoxicity by improving energy metabolism and antioxidant defense mechanism. 相似文献
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Nagarapu L Mateti J Gaikwad HK Bantu R Sheeba Rani M Prameela Subhashini NJ 《Bioorganic & medicinal chemistry letters》2011,21(14):4138-4140
A new series of 3-phenyl-N-[3-(4-phenylpiperazin-1yl)propyl]-1H-pyrazole-5-carboxamide derivatives were synthesized and investigated their anti-inflammatory activities using carrageenan-induced rat paw edema model in vivo. All the synthesized compounds were found to be potent anti-inflammatory agents. 相似文献
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Fine Mapping QTL for Drought Resistance Traits in Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) Using Bulk Segregant Analysis 总被引:1,自引:0,他引:1
Salunkhe AS Poornima R Prince KS Kanagaraj P Sheeba JA Amudha K Suji KK Senthil A Babu RC 《Molecular biotechnology》2011,49(1):90-95
Drought stress is a major limitation to rice (Oryza sativa L.) yields and its stability, especially in rainfed conditions. Developing rice cultivars with inherent capacity to withstand
drought stress would improve rainfed rice production. Mapping quantitative trait loci (QTLs) linked to drought resistance
traits will help to develop rice cultivars suitable for water-limited environments through molecular marker-assisted selection
(MAS) strategy. However, QTL mapping is usually carried out by genotyping large number of progenies, which is labour-intensive,
time-consuming and cost-ineffective. Bulk segregant analysis (BSA) serves as an affordable strategy for mapping large effect
QTLs by genotyping only the extreme phenotypes instead of the entire mapping population. We have previously mapped a QTL linked
to leaf rolling and leaf drying in recombinant inbred (RI) lines derived from two locally adapted indica rice ecotypes viz., IR20/Nootripathu using BSA. Fine mapping the QTL will facilitate its application in MAS. BSA was done
by bulking DNA of 10 drought-resistant and 12 drought-sensitive RI lines. Out of 343 rice microsatellites markers genotyped,
RM8085 co-segregated among the RI lines constituting the respective bulks. RM8085 was mapped in the middle of the QTL region
on chromosome 1 previously identified in these RI lines thus reducing the QTL interval from 7.9 to 3.8 cM. Further, the study
showed that the region, RM212–RM302–RM8085–RM3825 on chromosome 1, harbours large effect QTLs for drought-resistance traits
across several genetic backgrounds in rice. Thus, the QTL may be useful for drought resistance improvement in rice through
MAS and map-based cloning. 相似文献