Getting up to pee at night? Blame it on your genes. Researchers have shown that urination patterns are regulated by circadian rhythms (the molecular clock that controls your sleep/wake cycle). And its also because of a specific protein that controls how much urine your bladder can hold.

The protein is called connexin43 (Cx43) and previous studies have shown that bladders of mice with elevated Cx43 can hold less urine before signalling the urge to pee.

The study, published in the issue of Nature Communications by Japanese researchers led by Hiromitsu Negoro conducted a series of experiments linking the protein levels to circadian rhythms in mice. The levels of Cx43 in bladder muscle cells oscillate throughout the day in response to a well documented circadian molecule called Rev-erbo. Mice with an abnormal Cx43 gene urinated less frequently than normal mice.

The study is to provide researchers new ways of approaching problems like bedwetting in children and sleep interrupting pee urges in adults. [Nature Communications via Science]