Everyone has a natural body clock- a unique set of genes that they are born with. These genes turn on and off and tell other parts of the body what time it is and what to do. Inspired by this, scientists have developed a computer method called ZeitZeiger.
This new computer method uses a sample of human blood to accurately predict circadian time i.e., the timing of the day according to the body time.
This is the first ever study that demonstrates the use of genome-wide expression data. It might use to develop a biomarker of the circadian clock in human blood.
Lead author Jake Hughey said, “Our study demonstrates a method for predicting a person’s ‘internal’ time of day. In addition, it might eventually use to help diagnose and monitor circadian and sleep-related disorders, and also to personalize treatments.”
Scientists said, “Developing treatments that improve the function of or that account for the circadian system has the potential to improve multiple areas of human health.”
Hughey said, “Previous efforts to monitor the circadian clock in human tissues were based on a small number of individuals. But it is a small set of pre-selected genes. Our method, ZeitZeiger, uses 15 genes from across the human genome to predict circadian time.”
Scientists involved 498 samples from 60 individual to train ZeitZeiger to predict circadian time. That will be based on the genes expressed in blood samples. In addition, it will analyze how the circadian clock is affected by disturbances to sleep and light-dark cycles.
The individuals had drawn the blood throughout the day on a normal sleep-wake and light-dark cycle or following disruptions to their sleep-wake and light-dark cycle.
They then used their machine learning algorithm to analyze the RNA in the blood samples. Scientists figure out that a set 15 of genes capable of accurately predicting a person’s circadian time.
But they got more surprised when they find that 13 genes among all were not ‘core’ genes of the human circadian clock. Core genes are essential for the generation and regulation of circadian rhythms.
Hughey said, “Most of the genes that were selected for ZeitZeiger seem to be outputs of the body clock. They are not the gears controlling the clock, but the hands telling the time. This shows that when given data for almost every gene in the genome, the algorithm can figure out which set of genes gives the best predictions, even if they are not core clock genes.”
Scientists reported ZeitZeiger could be used to show how disruptions to sleep-wake and light-dark cycles affect the body clock. It could achieve state-of-the-art accuracy and also detected when the circadian clock was phase-shifted or dysfunctional.