Seasonal environmental changes regulate the expression of the histone variant macroH2A in an eurythermal fish

Abstract

Adaptation to cold and warm conditions requires dramatic change in gene expression. The acclimatization process of the common carp Cyprinus carpio L. in its natural habitat has been used to study how organisms respond to natural environmental changes. At the cellular level, adaptation to cold condition is accompanied by a dramatic alteration in nucleolar structure and a down regulation of the expression of ribosomal genes. We show that the enrichment of condensed chromatin in winter adapted cells is not correlated with an increase of the heterochromatin marker trimethyl and monomethyl K20H4. However, the expression of the tri methyl K4 H3 and of the variant histone macroH2A is significantly increased during the winter season together with a hypermethylation of CpG residues. Taking into account the properties of macroH2A toward chromatin structure and dynamics and its role in gene repression our data suggest that the increased expression of macroH2A and the hypermethylation of DNA which occurs upon winter-acclimatization plays a major role for the reorganization of chromatin structure and the regulation of gene expression during the physiological adaptation to a colder environment.

Rapid DNA Methylation Changes after Exposure to Traffic Particles

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Gene structure and seasonal expression of carp fish prolactin short receptor isoforms

“…These entail summer and winter rearrangements of molecular and cellular functions and involve the modulation of gene expression [Dietz and Somero, 1992;Vera et al, 1993;Kausel et al, 1999;Sarmiento et al, 2000;Fletcher et al, 2001;Alvarez et al, 2004;Pinto et al, 2005]. Similarly, temperature acclimation, even though a distinctive process [Somero and Hochachka, 2002] also demands gene expression regulation to provide the homeostatic state that fish require for survival [Goldspink, 1995;Figueroa et al, 1997;Arends et al, 1998;Gracey et al, 2004;Podrabsky and Somero, 2004].…”

Une aventure transdisciplinaire - À l’interface de la physique et de la biologie : le laboratoire Joliot-Curie de l’ENS de Lyon

“…Cette unité de lieu est incontestablement une condition nécessaire au développement de projets multidisciplinaires. À cet égard, la Avancées de la recherche [5,6]. (e) Prédiction des origines de réplication dans les génomes des mammifères à l'aide d'une méthodologie multiéchelle de détection de sauts ascendants dans des profils bruités d'asymétrie de composition : gènes sens (rouge), gènes antisens (bleu), régions intergéniques (noir) [7,8].…”