Effect of Exercise on Photoperiod-Regulated Hypothalamic Gene Expression and Peripheral Hormones in the Seasonal Dwarf Hamster Phodopus sungorus

Acknowledgments: Many thanks to Dana Wilson, Susan Hay, David Brown and Vivienne Buchan at RINH, Siegrid Hilken and Esther Lipokatic-Takacs at UVMH for the excellent technical support and advice provided. Many thanks are due to Claus Mayer of Biomathematics, Statistics Scotland for assistance with the statistical analysis of data. Author Contributions: Conceived and designed the experiments: IP SS FS PB. Performed the experiments: IP RD FS. Analyzed the data: IP RD FS SS PB. Wrote the paper: PB SS FS IP.Peer reviewedPublisher PD

The purification and properties of glutathione S-transferase from Ditylenchus myceliophagus

L'activité de la glutathion S-tranférase cytoplasmique chez #Dytylenchus myceliophagus$ a été attribuée à quatre isoenzymes, DmI, DmII, DmIII et DmIV, par combinaison de la chromatographie focalisante et de la chromatographie d'affinité au moyen de l'hexylglutathion. Un facteur endogène cytoplasmique a interféré avec les matrices d'affinité de la liaison entre les transférases cytosoliques et le glutathion, et la liaison ne s'est produite qu'après une purification préliminaire. Les quatre isoenzymes sont apparues être des homodimères avec des subunités de poids moléculaires respectifs de 25,3, 24, 26 et 25,7 kDa pour DmI, DmII, DmIII et DmIV. Les points isoélectriques pour DmI, DmII et DmIII sont de 7,28, 5,04 et 4,88. La séquence N-terminale de l'enzyme principale (DmIII) présente une très forte similarité de séquences avec la classe alpha GSTs des mammifères. En tout état de cause, les spécificités de substrats et les profils inhibiteurs de DmII, DmIII et DmIV montrent une ressemblance générale avec la classe mu des mammifères alors que DmI montre des caractéristiques plus proches de la classe alpha. (Résumé d'auteur

Kleinian Geometry and the N=2 Superstring

This paper is devoted to the exploration of some of the geometrical issues raised by the $N=2$ superstring. We begin by reviewing the reasons that $\beta$-functions for the $N=2$ superstring require it to live in a four-dimensional self-dual spacetime of signature $(--++)$, together with some of the arguments as to why the only degree of freedom in the theory is that described by the gravitational field. We then move on to describe at length the geometry of flat space, and how a real version of twistor theory is relevant to it. We then describe some of the more complicated spacetimes that satisfy the $\beta$-function equations. Finally we speculate on the deeper significance of some of these spacetimes.Comment: 30 pages, AMS-Te

The regulation of expression of low molecular weight RNA species in amphibian oocytes

During early oogenesis in Xenopus laevis about half of the 5S ribosomal RNA and most of the transfer RNA produced is stored in a ribonucleoprotein (RNP) complex that sediments at 42S. The other half of the 5S RNA produced is stored in a separate 73 RNP particle. As ribosome production gets underway in mid-oogenesis both the 1|2S and 7S particles disappear, the 5S rRNA being incorporated into the ribosomes, the tRNA being released as a slower sedimenting particle. Heterogeneity in the composition of the 42S particle was observed with respect to both protein and RNA components. The proteins of the 423 particle, Mr 48000 (P48) and Mr 43000 (P43) appear to be cleaved to smaller proteins. A derivative of P43 of Mr 17000 (P17) possibly becomes a ribosomal protein. Several observations are consistent with the view that P43 may accompany 53 RNA to the nucleolus before its cleavage product (P17) becomes incorporated into the ribosome. The chemical and structural relationships of P48, P43 and the protein component of the 73 RNP particle, transcription factor IIIA were studied and it was established that they are the products of three different genes. The 423 particle proteins have also been shown to have a binding affinity for 53 RNA genes (P48), tRNA genes (P43) or ribosomal genes (P43). In vivo inhibition of 5S RNA transcription by an anti-P48 antibody or tRNA transcription by an anti-P43 antibody suggest that these proteins may have a role in the transcription of these genes. Interactions between P43 and tRNA genes were analysed in most detail and indicating a specific interaction between these two components. The results taken as a whole suggest a central role for 42S particle proteins in particular P43, in co-ordinating the formation of the protein translational machinary

Preclinical models for obesity research

Acknowledgements The authors are funded by the Scottish Government, Rural and Environment Science and Analytical Services Division, Strategic Research Programme, ‘Food, Health and Wellbeing’ Theme. P.B. also acknowledges funding from Biotechnology and Biological Sciences Research Council (BBSRC; BB/M001504/1), J.G.M. from the European Union (EU)-funded Full4Health project (grant agreement no. 266408; Seventh Framework Programme [FP7/2007-2013]), and P.J.M. from BBSRC (BB/G014272/1).Peer reviewedPublisher PD

Steady-state energy balance in animal models of obesity and weight loss

Supported by European Union Seventh Framework Programme (FP7/2007-2013, n°266408 (Full4Health)), the Joint Programme of the Medical Faculty of Norwegian University of Science and Technology (NTNU) and St. Olav’s University Hospital, the Liaison Committee between the Central Norway Regional Health Authority and NTNU.Peer reviewedPostprin

Fat, carbohydrate and protein by oral gavage in the rat can be equally effective for satiation

This work was funded by the European Union Seventh Framework programme (Full4Health - grant number 266408) and the Scottish Government Rural and Environment Science and Analytical Services Division to the Rowett Institute. Funders had no role in the preparation of data or the manuscriptPeer reviewedPostprin

Differential coupling of the extreme C-terminus of G protein α subunits to the G protein-coupled melatonin receptors

AbstractMelatonin receptors interact with pertussis toxin-sensitive G proteins to inhibit adenylate cyclase. However, the G protein coupling profiles of melatonin receptor subtypes have not been fully characterised and alternative G protein coupling is evident. The five C-terminal residues of Gα subunits confer coupling specificity to G protein-coupled receptors. This report outlines the use of Gαs chimaeras to alter the signal output of human melatonin receptors and investigate their interaction with the C-termini of Gα subunits. The Gαs portion of the chimaeras confers the ability to activate adenylate cyclase leading to cyclic AMP production. Co-transfection of HEK293 cells expressing MT1 or MT2 melatonin receptors with Gαs chimaeras and a cyclic AMP activated luciferase construct provided a convenient and sensitive assay system for identification of receptor recognition of Gα C-termini. Luciferase assay sensitivity was compared with measurement of cyclic AMP elevations by radioimmunoassay. Differential interactions of the melatonin receptor subtypes with Gα chimaeras were observed. Temporal and kinetic parameters of cyclic AMP responses measured by cyclic AMP radioimmunoassay varied depending on the Gαs chimaeras coupled. Recognition of the C-terminal five amino acids of the Gα subunit is a requisite for coupling to a receptor, but it is not the sole determinant

Alternation between short- and long photoperiod reveals hypothalamic gene regulation linked to seasonal body weight changes in Djungarian hamsters (Phodopus sungorus)

This work was funded by the German Research Foundation (DFG, Emmy-Noether HE6383 to AH) and the British Society for Neuroendocrinology (Research grant to JB). The authors declare that they have no conflicts of interest.Peer reviewedPostprin