Methodology and theoretical basis of forward genetic screening for sleep/wakefulness in mice

Chika Miyoshi, Staci J. Kim, Takahiro Ezaki, Aya Ikkyu, Noriko Hotta-Hirashima, Satomi Kanno, Miyo Kakizaki, Mana Yamada, Shigeharu Wakana, Masashi Yanagisawa, Hiromasa Funato

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The regulatory network of genes and molecules in sleep/wakefulness remains to be elucidated. Here we describe the methodology and workflow of the dominant screening of randomly mutagenized mice and discuss theoretical basis of forward genetics research for sleep in mice. Our high-throughput screening employs electroencephalogram (EEG) and electromyogram (EMG) to stage vigilance states into a wake, rapid eye movement sleep (REMS) and non-REM sleep (NREMS). Based on their near-identical sleep/wake behavior, C57BL/ 6J (B6J) and C57BL/6N (B6N) are chosen as mutagenized and counter strains, respectively. The total time spent in the wake and NREMS, as well as the REMS episode duration, shows sufficient reproducibility with small coefficients of variance, indicating that these parameters are most suitable for quantitative phenotype-driven screening. Coarse linkage analysis of the quantitative trait, combined with whole-exome sequencing, can identify the gene mutation associated with sleep abnormality. Our simulations calculate the achievable LOD score as a function of the phenotype strength and the numbers of mice examined. A pedigree showing a mild decrease in total wake time resulting from a heterozygous point mutation in the Cacna1a gene is described as an example.

Original languageEnglish (US)
Pages (from-to)16062-16067
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number32
StatePublished - Aug 6 2019


  • C57BL/6 substrains
  • Cacna1a
  • Dominant screening
  • ENU mutagenesis
  • Linkage analysis

ASJC Scopus subject areas

  • General


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