What is "doubletime"

Doubletime is a documentary film about the sport of modern-day jump roping and Double Dutch. The film follows two disparate teams—one suburban white and one inner-city black—as they train to compete against each other for the very first time.

Doubletime (dbt) also known as discs overgrown (dco) is a gene that encodes the double-time protein (DBT) in Drosophila melanogaster. The double-time protein is a kinase that phosphorylates PER protein that regulates the molecularly-driven, biological clock controlling circadian rhythm. The mammalian homolog of doubletime is casein kinase I, epsilon. Different Mutations in the dbt gene have been shown to cause lengthening, shortening, or complete loss in period of locomotor activity in flies. Drosophila and certain vertebrate Casein Kinase Id shows circadian function that has been evolutionary conserved over long time spans.