Sexual Interactions Influence circadian rhythms in Drosophila melanogaster
January 10, 2014
Researchers in Okayama University Graduate School of Natural Science and Technology showed that the circadian rhythm of males are influenced by that of females in Drosophila melanogaster. They also found that Interaction with females influences the male' s clock cells in the brain.
The findings were published online on December 18, 2013 in the journal PLos One.
Approximately 150 neurons are determined to be clock cells in the brain of Drosophila. DN1 is one of the neurons. The clock proteins in the clock cells have an expression rhythm that varies the level of the proteins throughout a 24-hour period.
Taishi Yoshii and his colleagues used female mutant flies that have an approximately 19-hour period clock to investigate whether the clock of wild-type male flies can be influenced by the presence of the mutant flies of the opposite sex at behavioral and neural levels. Compared with single flies, paired flies became more active during the mutants' active phase, and were less active during the wild-types' active phase. Furthermore, in those pairs, clock protein cycling in the DN1 neurons in the wild-type male brain were slightly influenced by their partners.
Disturbed circadian rhythm is a causal factor of many diseases, including sleep disorder, depression, and obesity. The study results suggest that social factors could be responsible for disturbed circadian rhythm in humans as well. In future studies, an association between the circadian clock and social factors in diseases such as sleep disorders could be revealed.
The study was supported by the Japan Society for the Promotion of Science，Inamori Foundation and Sumitomo Foundation.
Mototaka Senda, Ph.D.
Intellectual Property Office, Organization for Research Promotion and Collaboration, Okayama University
Fremont, California USA
Taishi Yoshii, Ph.D.
Graduate School of Natural Science and Technology, Okayama University, Okayama Japan