Systems biology is an approach to dissection of complex traits that explicitly recognizes the impact of genetic, physiological, and environmental interactions in the generation of phenotypic variation. We describe comprehensive transcriptional and metabolic profiling in Drosophila melanogaster across four diets, finding little overlap in modular architecture. Genotype and genotype-by-diet interactions are a major component of transcriptional variation (24 and 5.3% of the total variation, respectively) while there were no main effects of diet (<1%). Genotype was also a major contributor to metabolomic variation (16%), but in contrast to the transcriptome, diet had a large effect (9%) and the interaction effect was minor (2%) for the metabolome. Yet specific principal components of these molecular phenotypes measured in larvae are strongly correlated with particular metabolic syndrome-like phenotypes such as pupal weight, larval sugar content and triglyceride content, development time, and cardiac arrhythmia in adults. The second principal component of the metabolomic profile is especially informative across these traits with glycine identified as a key loading variable. To further relate this physiological variability to genotypic polymorphism, we performed evolve-and-resequence experiments, finding rapid and replicated changes in gene frequency across hundreds of loci that are specific to each diet. Adaptation to diet is thus highly polygenic. However, loci differentially transcribed across diet or previously identified by RNAi knockdown or expression QTL analysis were not the loci responding to dietary selection. Therefore, loci that respond to the selective pressures of diet cannot be readily predicted a priori from functional analyses.
Purple-fleshed sweetpotatoes (PFSP) can be a healthy food choice for consumers and a potential source for natural food colorants. This study aimed to identify anthocyanins and anthocyanidins in PFSP, and to evaluate the effect of thermal processing on these polyphenolic compounds. Freeze-dried powder of raw and steamed samples of three PFSP varieties were extracted with acidified methanol using a Dionex ASE 200 accelerated solvent extractor. Seventeen anthocyanins were identified by HPLC-DAD/ESI-MS/MS for Stokes Purple and NC 415 varieties with five major compounds: cyanidin 3-caffeoylsophoroside-5-glucoside, peonidin 3-caffeoylsophoroside-5-glucoside, cyanidin 3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside, peonidin 3-caffeoyl-p-hydroxybenzoyl-sophoroside-5-glucoside, and peonidin-caffeoyl-feruloylsophoroside-5-glucoside. Okinawa variety showed 12 pigments with 3 major peaks identified as cyanidin 3-caffeoylsophoroside-5-glucoside, cyanidin 3-(6 '',6'''-dicaffeoylsophoroside)-5-glucoside and cyanidin 3-(6 ''-caffeoyl-6"'-feruloylsophoroside)-5-glucoside. Steam cooking had no significant effect on total anthocyanin content or the anthocyanin pigments. Cyanidin and peonidin, which were the major anthocyanidins in the acid hydrolyzed extracts, were well separated and quantified by HPLC with external standards. Cyanidin and peonidin, which contribute to the blue and red hues of PFSP, can be simply quantified by HPLC after acid hydrolysis of the anthocyanins.
Although most genetic association studies are performed with the intention of detecting nucleotide polymorphisms that are correlated with a complex trait, transcript abundance should also be expected to associate with diseases or phenotypes. We performed a scan for such quantitative trait transcripts in adult female heads of the fruit fly ( Drosophila melanogaster) that might explain variation for nicotine resistance. The strongest association was seen for abundance of ornithine aminotransferase transcripts, implicating detoxification and neurotransmitter biosynthesis as mediators of the quantitative response to the drug. Subsequently, genetic analysis and metabolite profiling confirmed a complex role for ornithine and GABA levels in modification of survival time upon chronic nicotine exposure. Differences between populations from North Carolina and California suggest that the resistance mechanism may be an evolved response to environmental exposure.
A comparative study in eight healthy normotensive males of the effects on blood pressure, heart rate and 3-adrenoceptor function following single oral doses of adimolol (600 mg), propranolol (240 mg) and placebo. Both active treatments produced small but significant reductions in blood pressure and heart rate, supine and erect. These effects persisted for up to 7 days after adimolol. The heart rate increases following both dynamic exercise and intravenous isoprenaline were attenuated by both propranolol and adimolol. With adimolol evidence of functional ,3-adrenoceptor antagonism was sustained for up to 7 days. Lymphocyte P-adrenoceptor binding studies showed that both adimolol and propranolol significantly reduced affinity for 3-adrenoceptors. In addition, adimolol significantly reduced receptor number and even by 3 days after dosing Bmax had only returned to half the control value. ot-adrenoceptor was detected in for up to 3 days dosing. mean terminal elimination half-life 14 h, compared This study confirms that adimolol has prolonged 13-adrenoceptor antagonist activity with effects persisting for up to 7 days after a single dose. The reduction in 13-adrenoceptor number following adimolol suggests that this prolonged effect may not be solely due to competitive antagonism but may additionally depend upon non-competitive antagonism at 3-adrenoceptors.
Patterns of variation for the solanidine-based glycoalkaloids have been determined for tuber material of genebank accessions of landraces of the cultivated potato and three closely-related wild species. Total levels were low in the cultivated taxa investigated,S. phureja, S. stenotomum, and the tetraploidS. tuberosum in its two formsS. tuberosum ssp.tuberosum andS. tuberosum ssp.andigena. The only solanidine-based glycolkaloids found in the tubers investigated in this study wereα-solanine andα-chaconine, with one additional related compound, dehydrocommersonine, found in tubers of an accession ofS. canasense. The ratio of chaconine : solanine differed markedly from a mean of 0.98 inS. phureja to 2.28 in ChileanS. tuberosum ssp.tuberosum. The chaconine : solanine ratio was relatively constant within these two taxa, reflecting their relatively narrow genetic bases, but was much more variable within the taxa regarded as ancestral,S. stenotomum andS. tuberosum ssp.andigena. The wild speciesS. sparsipilum has been implicated in the origin of the tetraploid potato,S. tuberosum, but there was no support for this from the patterns of variation in chaconine : solanine ratio. The cline of chaconine : solanine ratios in cultivated potatoes along the spine of S. America does not appear to relate to the influence of local wild species through introgression, but may instead reflect differing selective pressures acting in different parts of the native range of the cultivated potato.
Estimating intake of phyto-oestrogens (PO) is difficult because there is inadequate information on the PO content of foods. Development of a biomarker of intake is therefore necessary for carrying out epidemiological studies. We aimed to validate a newly constructed PO database, containing more than 600 values assigned to foods by using duplicate diet analysis, and to investigate the relationships between measured PO intake, urinary excretion and plasma concentrations of PO. Fourteen subjects with estimated dietary intakes of PO ranging from 0 to 44mg/d, measured by 7d weighed intake, completed a duplicate diet collection over 24h. Concurrently, a 24h urine collection, validated using p -aminobenzoic acid, was obtained and one timed spot plasma sample taken. Duplicate diets, complete urine collections and plasma samples were analysed for total genistein and daidzein using liquid chromatography–MS to determine PO intake. The potential for 24h urinary excretion and plasma PO concentrations to reflect dietary intake was investigated. Mean estimated and measured dietary PO intakes were 12·3 and 11·0mg/d respectively. The correlation between estimated intake and measured intake of PO was highly significant ( r 0·98, P <0·001). Urinary excretion (24h) and plasma concentrations of PO were significantly related to measured dietary PO intake (r 0·97, P <0·001 and r 0·92, P <0·001 respectively). The relationship between 24h urinary PO excretion and timed plasma concentrations was also significant ( r 0·99, P <0·001). These findings validate the PO database and indicate that 24h urinary excretion and timed plasma concentrations can be used as biomarkers of PO intake.
Objective: To study the variation in genistein+daidzein intake over a 6-month period and test the reliability of 24 h urinary isoflavones as a biomarker of exposure over time. Design: Dietary genistein+daidzein intake was assessed at various time points throughout six months in 15 healthy subjects. Group 1 (n=8) followed nonsupplemented diets and Group 2 (n=7) took a 35 mg/d isoflavone supplement for 3 months and each subject provided a 24 h urine collection, validated with para-aminobenzoic acid, during weeks 7, 15 and 19. Urine was analysed for genistein and daidzein using LC-MS. Results: Isoflavone intake in Groups 1 and 2 ranged from 0.00 to 1.1 mg/d and 0.1 to 53.1 mg/d, respectively. Urine excretion for both groups ranged from 0.20 to 9.56 mg/d. The relationship between 24 h excretion and isoflavone intake is y=0.44 × ±0.03(standard deviation) + 1.57; r=0.89, P<0.001. Conclusion: The 24 h urinary isoflavones can be used as biomarkers of isoflavone exposure over time.
BackgroundThe current study assessed the value of spot urine and plasma samples as biomarkers of phyto-oestrogen exposure.
We have examined the effects of 7 days treatment with beta adrenoceptor antagonists in 8 healthy volunteers in a placebo controlled, crossover study. We investigated three beta-adrenoceptor antagonists (atenolol, oxprenolol, and propranolol), which have differing profiles of selectivity and partial agonist properties (intrinsic sympathomimetic activity, ISA).
Several markers of oxidative processes have been measured in leaves of Phaseolus vulgalis infected with Botrytis cinerea, with the specific objective of investigating changes induced by this necrotrophic pathogen in tissue remote from the lesion. There was a progressive decrease with time in the contents of ascorbic acid (AA) in apparently healthy tissues from infected plants and non-inoculated plants grown under identical high-humidity conditions (abiotically stressed controls), and for periods > 48 h this decrease was greater in the infected plants. This decline in AA content was accompanied by an elevation in the intensity of the electron paramagnetic resonance (EPR) signal from adducts of the spin trap alpha-(4-pyridyl-1-oidde)-N-t-butylnitrone (POBN), a destabilisation of the (monodehydro) ascorbate radical (Asc) signal in the presence of POBN, and an increase in the ratio of Asc to AA in samples studied in the absence of the spin trap. These results are consistent with a shift in redox status to more oxidising conditions in apparently healthy tissue of infected plants and indicate the prevalence of chemical processes that are distinctly different from those in uninfected plants. However, no differences in lipid peroxidation products or the single-peak free radical and Fe(III) (g = 4.27) EPR signals were observed between these tissues distant from the lesions and those from abiotically stressed controls. In addition, the pathogen-derived sesquiterpene toxin botrydial and a second Mn(H) EPR signal, both of which are associated with Botrytis infection, were not detected in these 'apparently healthy' tissues. (C) 2003 Society of Chemical Industry.
s: Raspberry, strawberry and black currant exhibit a significant range ofantioxidant capacities. Our studies suggest that for the whole fruit phenolic com-pounds are the determinant factors for antioxidant capacity and that, not surprisingly,the major phenolics compounds vary from species to species. This presents signifi-cantly different targets for breeding should antioxidant status be deemed to be a qual-ity trait to aim for. In addition, we have shown that the relative protective effects ofvitamin C and phenolics could be separated and compared at least with regard to LDLoxidation and, by inference, the initial stages of atherosclerosis. These initial studiessuggest that the chemistries representative of Rubus , here Rubus ideaus , are the mostpromising target for more detailed in vivo studies. Keywords: Soft fruit species, antioxidants. Introduction Premature deaths in Scotland substantially exceed those in most Westerncountries with coronary heart disease, strokes and cancers the major causes. Free rad-icals are implicated in the pathogenesis of these diseases and it’s now thought that aninsufficient intake of antioxidants is a contributory factor. It is likely that the healthof the population would improve if antioxidant status were enhanced by consumptionof foods rich in antioxidant nutrients. Potentially important sources of antioxidant-richfood are the locally grown soft fruits; strawberries (
Antioxidant capacities were determined on a range of soft fruit, including Fragaria, Rubus and Ribes. These covered a wide range although, in general, the most coloured fruit exhibited the greatest antioxidant abilities. The colour was derived from anthocyanin compounds whose antioxidant efficacy depended of the number of hydroxyl groups and the degree and type of glycosylation. However, antioxidant capacity of the fruit did not directly relate to anthocyanin or vitamin C content. A strong correlation with total phenol content suggests that other polyphenols also contribute to the antioxidant capacity of soft fruit. Determination of total phenols may form the basis of a simple screen in breeding programmes aimed at increasing the antioxidant status of fruit.
Infection of leaves of Arabidopsis thaliana with conidial suspensions of the necrotrophic pathogen Botrytis cinerea resulted in a large decrease in the level of ascorbic acid and increases in intensity of a single-peak free radical and Fe(III) (g=4.27) signals in electron paramagnetic resonance (EPR) spectra. These changes were not confined to the spreading lesions or associated areas of chlorosis, but extended to other apparently healthy tissues in the infected leaves. They are, therefore, consistent with the existence of high levels of oxidative stress being generated as a result of the infection process. The expected accompanying increases in levels of the aldehydic products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE), were not observed, and in the case of MDA the levels in tissue from infected plants were appreciably lower than in the healthy controls. These last findings are surprising and demonstrate a difference in the response of A. thaliana to infection with B. cinerea compared with tissues from other plant families studied previously.
Free radical adducts of the spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone have been observed by electron paramagnetic resonance spectroscopy in detached fruits ofCapsicum annuum investigated 5 days after infection withBotrytis cinerea.The spectra of these adducts were at a maximum within the soft rot lesion, but they could also be detected at distances up to 50 mm from the edge of the lesion in samples following main vascular bundles. At distances greater than 40 mm, the spectrum of the ascorbate radical was also seen, and at greater distances from the lesion it was the only radical detected. With samples taken from parenchyma tissue adjacent to the vascular bundles there was little adduct formation and the ascorbate radical could be detected, albeit with reduced intensity compared to healthy tissue, at distances as small as 10 mm from the edge of the lesion. This observation of chemical changes at considerable distances from the infected tissue is in contrast to previous observations on the behaviour of other markers of oxidative stress (e.g., 4-hydroxynonenal, malondialdehyde, single-peak free radical, and Fe(III) (g = 4.27) electron paramagnetic resonance signals), where their levels decreased rapidly outside of the soft rot.
A method using liquid chromatography — atmospheric pressure chemical ionisation mass spectrometry was evaluated for determining the molecular species composition of phospholipids (phosphatidylcholines from soybean, egg yolk and bovine liver) after conversion to diacylglycerol nicotinate derivatives. The structures could be deduced from pseudo-molecular ions ([MH-123]+) and three pairs of monoacyl containing fragment ions. All molecular species in mixed peaks were readily identified and many minor components, earlier not encountered in the samples under investigation, were identified. Acyl chain regioisomers were readily distinguished by the ratio of the [MH–RCHCO]+ ions. Molecular species differing only in the position of the double bonds in one polyunsaturated acyl chain were separated on the basis of retention times. A half quantitative estimation of the molecular species composition of complex samples was achieved by a combination of UV detection and, for mixed peaks, the areas of [MH-123]+ ions.