XTHs from Fragaria vesca: Genomic structure and transcriptomic analysis in ripening fruit and other tissues

Indexación: Scopus.Background: Fragaria vesca or 'woodland strawberry' has emerged as an attractive model for the study of ripening of non-climacteric fruit. It has several advantages, such as its small genome and its diploidy. The recent availability of the complete sequence of its genome opens the possibility for further analysis and its use as a reference species. Fruit softening is a physiological event and involves many biochemical changes that take place at the final stages of fruit development; among them, the remodeling of cell walls by the action of a set of enzymes. Xyloglucan endotransglycosylase/hydrolase (XTH) is a cell wall-associated enzyme, which is encoded by a multigene family. Its action modifies the structure of xyloglucans, a diverse group of polysaccharides that crosslink with cellulose microfibrills, affecting therefore the functional structure of the cell wall. The aim of this work is to identify the XTH-encoding genes present in F. vesca and to determine its transcription level in ripening fruit. Results: The search resulted in identification of 26 XTH-encoding genes named as FvXTHs. Genetic structure and phylogenetic analyses were performed allowing the classification of FvXTH genes into three phylogenetic groups: 17 in group I/II, 2 in group IIIA and 4 in group IIIB. Two sequences were included into the ancestral group. Through a comparative analysis, characteristic structural protein domains were found in FvXTH protein sequences. In complement, expression analyses of FvXTHs by qPCR were performed in fruit at different developmental and ripening stages, as well as, in other tissues. The results showed a diverse expression pattern of FvXTHs in several tissues, although most of them are highly expressed in roots. Their expression patterns are not related to their respective phylogenetic groups. In addition, most FvXTHs are expressed in ripe fruit, and interestingly, some of them (FvXTH 18 and 20, belonging to phylogenic group I/II, and FvXTH 25 and 26 to group IIIB) display an increasing expression pattern as the fruit ripens. Conclusion: A discrete group of FvXTHs (18, 20, 25 and 26) increases their expression during softening of F. vesca fruit, and could take part in cell wall remodeling required for softening in collaboration with other cell wall degrading enzymes.https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-017-4255-

Olfactory Learning Deficits in Mutants for leonardo, a Drosophila Gene Encoding a 14-3-3 Protein

AbstractStudies of Drosophila and other insects have indicated an essential role for the mushroom bodies in learning and memory. The leonardo gene encodes a Drosophila protein highly homologous to the vertebrate 14-3-3ζ isoform, a protein well studied for biochemical roles but without a well established biological function. The gene is expressed abundantly and preferentially in mushroom body neurons. Mutant alleles that reduce LEONARDO protein levels in the mushroom bodies significantly decrease the capacity for olfactory learning, but do not affect sensory modalities or brain neuroanatomy that are requisite for conditioning. These results establish a biological role for 14-3-3 proteins in mushroom body–mediated learning and memory processes, and suggest that proteins known to interact with them, such as RAF-1 or other protein kinases, may also have this biological function

Impact of Guidance and Counselling Services on Students’ Behaviour Modificatio between Selected Public Urban and Rural Secondary Schools in Rift Valley Province, Kenya

The study sought to establish and compare the impact of guidance and counselling services on students’ behaviour modification in social and emotional adjustment in the selected public urban and rural secondary schools in Rift Valley Province, Kenya. The study adopted ex post-facto causal comparative research design The research population was form 4 students in 24 secondary schools from municipality: Eldoret, Naivasha and Nakuru,and rural/district: Uasin Gishu, Kuresoi and Molo Simple random, stratified and purposive sampling techniques were used to select 346 students, 48 school counsellors and 48 school administrators as respondents. Quantitative data was collected by administering questionnaires to students and school guidance counsellors while Qualitative data was collected through conducting an interview schedule to school administrators. Questionnaires were pilot tested before use and were found to have reliability coefficient of 0.8. The study employed one way analysis of variance (ANOVA) to test the hypothesis at 0.05 level of significance.The Statistical Packages for Social Sciences (SPSS) version 20.0.helped in data analysis. The findings of the study indicated that guidance and counselling services in secondary schools had statistically significant impact on the level of social and emotional adjustments. Rural schools indicated high level of impact of guidance and counselling services where female students expressed higher level of behaviour modification in social and emotional adjustment It was concluded that guidance and counselling services in secondary schools helps in modifying students’ behaviour in social and emotional adjustments. Stakeholders in education sector and other youth institutions could find these findings useful in addressing secondary schools students’ social and emotional needs. Keywords: Behaviour Modification, Guidance and Counselling Services, Social and Emotional Adjustment, Rural andUrban Secondary School

Relative toxicity of gossypol enantiomers in laying and broiler breeder hens

Gossypol, a natural component of cottonseed meal, exists in positive (+) or negative (−) enantiomeric forms, and their levels and ratio could be altered by developing new genetic strains of cotton. Two experiments were conducted to determine the relative toxicity of the individual gossypol enantiomers in laying and broiler breeder hens. In the first experiment, 25 individually caged Hy-Line W-36 forty-three-week-old laying hens were fed a standard corn-soy diet supplemented with either no gossypol or the individual enantiomers at 200 and 400 mg/kg of diet for 20 d (5 hens/treatment). In the second experiment, 15 individually caged Cobb 500 fast-feathering 44-wk-old broiler breeder hens were fed a standard corn-soy-wheat middlings diet supplemented with either no gossypol or the individual enantiomers at 400 mg/kg of diet for 18 d (5 hens/treatment). In both experiments, feed intake, egg production, and egg weight were determined daily. All eggs were individually opened and scored for yolk discoloration. At the end of both experiments, several organ and tissue samples were collected for gossypol analyses. In both experiments, the addition of (+)-gossypol to the diet reduced egg production. Only laying and broiler breeder hens fed (+)-gossypol produced eggs with severe yolk discoloration (score ≥ 4). Total feed intake was lower (P < 0.05) in laying hens fed the 400 mg/kg level of (+)-gossypol compared with laying hens fed the other dietary treatments. In contrast, broiler breeder hens consumed less of the diet supplemented with (−)-gossypol. In both experiments, tissue accumulation of (+)-gossypol was higher than (−)-gossypol, with the exception of bile and excreta. The results suggest that in hens the ingestion of (+)-gossypol has a greater effect on egg yolk discoloration than the consumption of (−)-gossypol

Relative toxicity of gossypol enantiomers in broilers

Use of cottonseed meal in poultry diets has been avoided in large part because of fear of gossypol toxicity. Gossypol exists naturally as a mixture of 2 enantiomers that exhibit different biological activities. Two experiments were conducted to determine the relative toxicity of gossypol enantiomers on broilers. In the first experiment, 3-d-old broilers were fed a standard diet containing 0, 100, 200, 300, or 400 mg of gossypol from gossypol acetic acid per kilogram of diet from 3 to 42 d of age. This form of gossypol contains both enantiomers in an equimolar ratio. Each dietary treatment consisted of 6 replicate pens of 4 birds. In the second experiment, 3-dold broilers were divided into 15 pens of 4 birds each and fed a standard diet supplemented with either no gossypol or one of the gossypol enantiomers at 200 or 400 mg/kg of diet from 3 to 21 d of age. In both experiments, feed intake and BW gain were measured. In addi- (Key words: cottonseed meal, gossypol, gossypol enantiomer, broiler) 2005 Poultry Science 84:1376–1382 INTRODUCTION Cottonseed meal (CSM) could be an attractive alternative protein source for poultry diets, but concern over the presence of the potentially toxic agent, gossypol, has limited its use. Gossypol [1,1′,6,6′,7,7′-hexahydroxy-5,5′- diisopropyl-3, 3′-dimethyl-(2, 2′- binaphthalene)-8, 8′-dicarboxaldehyde] is a polyphenolic compound located in pigment glands that are distributed throughout the cotton plant. Gossypol is composed of 2 naphthalene rings with restricted rotation around the bond connecting the rings. As a result of this restricted rotation, gossypol occurs naturally as a mixture of 2 enantiomers [(+)- and (−)- 2005 Poultry Science Association, Inc. Received for publication February 7, 2005. Accepted for publication May 5, 2005. 1This research was supported in part by grant 2631RE683-118 from the Georgia Cotton Commission, Perry, GA. 2Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture. 3To whom correspondence should be addressed: [email protected]. 1376 tion, several organ and tissue samples were collected at 21 d (experiments 1 and 2) and 42 d (experiment 1) of age and analyzed for gossypol. In experiment 1, feed consumption and BW gain were reduced (P < 0.05) at 21 and 42 d for the birds fed the highest level of gossypol. The concentration of gossypol in the heart, kidney, and plasma were equivalent at 21 and 42 d of age. In experiment 2, total feed consumption was reduced only in birds consuming (−)-gossypol, but BW gains were lower for birds fed either enantiomer. However, (−)-gossypol was more detrimental to growth than (+)-gossypol. The liver had the highest tissue concentration of both enantiomers, and accumulation of (+)-gossypol was higher than (−)- gossypol in all tissues examined. No racemization of the enantiomers was apparent in the tissues analyzed. Our results indicated that both gossypol enantiomers were toxic to broilers but that (−)-gossypol was more harmful to efficient broiler production than (+)-gossypol

Neutrinoless Double Beta Decay in Light of SNO Salt Data

In the SNO data from its salt run, probably the most significant result is the consistency with the previous results without assuming the 8B energy spectrum. In addition, they have excluded the maximal mixing at a very high confidence level. This has an important implication on the double beta decay experiments. For the inverted or degenerate mass spectrum, we find |_{ee}| > 0.013 eV at 95% CL, and the next generation experiments can discriminate Majorana and Dirac neutrinos if the inverted or degenerate mass spectrum will be confirmed by the improvements in cosmology, tritium data beta decay, or long-baseline oscillation experiments.Comment: REVTEX4, three figures. Now uses the updated SK atmospheric data rather than naive rescaling. Conclusion unchanged. References adde

Global and Unified Analysis of Solar Neutrino Data

We discuss the status of the solutions of the solar neutrino problem in terms of oscillations of $\nu_e$ into active or sterile neutrinos. We present the results of a global fit to the full data set corresponding to the latest data presented at the $\nu$-2000 conference. We show the possible solutions in the full parameter space including both MSW and vacuum, as well as quasi-vacuum oscillations (QVO) and matter effects for mixing angles in the second octant (the so called dark side). Our conclusion is that from the statistical point of view, all solutions for oscillations into active neutrinos: LMA, LOW, SMA and the QVO solutions are acceptable since they all provide a reasonable GOF to the full data set. The same holds for the SMA solution for oscillations into sterile neutrinos. LMA and LOW-QVO solutions for oscillations into active neutrinos seem slightly favoured over SMA solutions for oscillations into active or sterile neutrinos. We also analyze the dependence of these conclusions on the uncertainty of the SSM $^8$B flux and on the removal of the data from one of the experimental rates. We also present the results in the framework of four neutrino oscillations which allows for oscillations into a state which is a combination of active and sterile neutrino.Comment: 18 pages with 18 postscript figures included (some of them bitmapped for compression, better resolution at http://ific.uv.es/~penya

Dynamics of the Hubbard model: a general approach by time dependent variational principle

We describe the quantum dynamics of the Hubbard model at semi-classical level, by implementing the Time-Dependent Variational Principle (TDVP) procedure on appropriate macroscopic wavefunctions constructed in terms of su(2)-coherent states. Within the TDVP procedure, such states turn out to include a time-dependent quantum phase, part of which can be recognized as Berry's phase. We derive two new semi-classical model Hamiltonians for describing the dynamics in the paramagnetic, superconducting, antiferromagnetic and charge density wave phases and solve the corresponding canonical equations of motion in various cases. Noticeably, a vortex-like ground state phase dynamics is found to take place for U>0 away from half filling. Moreover, it appears that an oscillatory-like ground state dynamics survives at the Fermi surface at half-filling for any U. The low-energy dynamics is also exactly solved by separating fast and slow variables. The role of the time-dependent phase is shown to be particularly interesting in the ordered phases.Comment: ReVTeX file, 38 pages, to appear on Phys. Rev.

Experimental Results of Neutron Fluence Outside an Iron Shield in the Forward Direction

This work represents the first systematic study at a high energy accelerator of the depth dependence of neutron fluence in longitudinal shielding

Homogenization of weakly coupled systems of Hamilton--Jacobi equations with fast switching rates

We consider homogenization for weakly coupled systems of Hamilton--Jacobi equations with fast switching rates. The fast switching rate terms force the solutions converge to the same limit, which is a solution of the effective equation. We discover the appearance of the initial layers, which appear naturally when we consider the systems with different initial data and analyze them rigorously. In particular, we obtain matched asymptotic solutions of the systems and rate of convergence. We also investigate properties of the effective Hamiltonian of weakly coupled systems and show some examples which do not appear in the context of single equations.Comment: final version, to appear in Arch. Ration. Mech. Ana