Dynamic regulation of gene expression in the dmpARC and ependymal layer in the Siberian hamster during seasonal weight change

Perry Barrett, Dana Lorraine Wilson, Julian Mercer, Alexander Ross, Lynn Bell, Francis J. P. Ebling, Alex Schuhler, Peter John Morgan

Research output: Contribution to journalArticlepeer-review


Physiological and behavioural adaptations of the Siberian hamster which occur as part of a strategy to survive environmental changes encountered in winter include a reduction in food intake and loss of body fat accounting for 30–40% of body weight. Seasonal body weight loss offers the advantage of a physiological model of body weight regulation as opposed to an enforced or manipulated loss through dietary, pharmacological or genomic intervention.

Using several approaches, we are investigating the mechanism by which the hamster achieves this dramatic weight loss. A microarray and a candidate gene approach, coupled with in situ hybridization, have uncovered photoperiod-regulated gene expression in the dorsal medial posterior arcuate nucleus (dmpARC). Recent advances reveal the dynamic responses of the dmpARC to photoperiod, with several genes up-regulated during the period of weight loss. These include the melanocortin 3 receptor and the immediate early gene c-fos, implicating significant activation of neurons in the dmpARC in short days (SD). Noteworthy is the constitutive presence of c-fos both at the level of mRNA and protein in the dmpARC of SD hamsters. In the context of the SD increase seen in VGF mRNA (a gene implicated in energy balance), the data points to a very important role for the dmpARC in mediating body weight and other seasonal responses. Dual in situ hybridization reveals that c-fos and VGF are co-expressed.

In addition to the dmpARC, we have uncovered photoperiodic regulation of several mRNA sequences in the ependymal layer of the third ventricle adjacent to the arcuate nucleus and dmpARC. These include the orphan G protein coupled receptor GPR50, the intermediate filament protein, Nestin, and the retinoic acid binding protein CRBP1. These latter discoveries suggest that the ependymal layer has a role to play in seasonal response but also may have important implications for the role of the ependymal layer in general. (This work was supported by Scottish Executive Environment and Rural Affairs Department.)

Original languageEnglish
Pages (from-to)7-8
Number of pages2
JournalFrontiers in Neuroendocrinology
Issue number1
Publication statusPublished - May 2006


Dive into the research topics of 'Dynamic regulation of gene expression in the dmpARC and ependymal layer in the Siberian hamster during seasonal weight change'. Together they form a unique fingerprint.

Cite this