Une étude de l’Institut Cellule Souche et Cerveau de l’INSERM (Bron)  en collaboration avec une équipe américaine du Salk Institute (San Diego) vient d’être publiée dans la revue Science. Cette étude est le premier atlas répertoriant le profil de l’expression des gènes dans plus de 64 horloges au cours des 24 heures chez un animal diurne, un primate non-humain. Ces données ouvrent des perspectives médicales importantes car  82% des gènes qui cyclent codent pour des protéines ciblées par des médicaments.

Diurnal transcriptome atlas of a primate across major neural and peripheral tissues.

Mure LS, Le HD, Benegiamo G, Chang MW, Rios L, Jillani N, Ngotho M, Kariuki T, Dkhissi-Benyahya O, Cooper HM, Panda S.

Science. 2018 Feb 8. pii: eaao0318. doi: 10.1126/science.aao0318. [Epub ahead of print]

Abstract

Diurnal gene expression patterns underlie time of the day-specific functional specialization of tissues. However, available circadian gene expression atlases of a few organs are largely from nocturnal vertebrates. We report the diurnal transcriptome of 64 tissues, including 22 brain regions, sampled every 2 hours over 24 hours, from the primate Papio anubis (baboon). Genomic transcription was highly rhythmic with up to 81.7% of protein-coding genes showing daily rhythms in expression. In addition to tissue-specific gene expression, the rhythmic transcriptome imparts another layer of functional specialization. Most of ubiquitously expressed genes that participate in essential cellular functions exhibit rhythmic expression in a tissue-specific manner. The peak phases of rhythmic gene expression clustered around dawn and dusk with a « quiescent period » during early night. Our findings also unveil a different temporal organization of central and peripheral tissues between diurnal and nocturnal animals.