New findings on the internal clock of the fruit fly

The Westfälische Wilhelms-Universitt Münster is located in Germany.

The sleep-wake rhythm is controlled by the internal clock of most living organisms. The internal rhythm lasts one day and is regulated by various clock genes. The internal clock and the external day-night rhythm are synchronized with the help of factors such as light and temperature. A team led by Prof. Stanewsky from the University of Münster has shown that a certain ion transport protein plays a role in regulating the rhythms of the flies.

There is a signaling cascade in the brain. The internal clock of the fruit fly is regulated by aprotein known as Quasimodo. It is a part of the cell and helps to pass light signals as external regulators. Quasimodo interacts with NKCC. The function of it is to transport chloride ion into the cell. The researchers examined for the first time the counterpart of NKCC, the potassium chloride cotransporter KCC.

The balance between the two cotransporters is what determines the chloride content in the cell. The function of the internal clock is determined by the chloride content of a neuron. When there is a high chloride content, it stimulates the cell and when it is low, it blocks the signal from entering the cell.

The two cotransporters NKCC and KCC are from an evolutionary point of view. The activity of NKCC and its counterpart plays an important role in the internal clock of mammals, but not of flies.

The team demonstrated that flies in which one of the three influencing factors examined is particularly active or inactive show an abnormal rhythmic behavior under constant light. The function of the clock in flies is degraded in light due to the fact that there is one essentialProtein in the clock which is degraded in light.

The flies were exposed to a long day-night cycle which caused them to have high activity in the morning. The increased activity only occurred when less NKCC and less Quasimodo were present.

The researchers used a combination of methods. They used cell-specific genetic manipulation to produce strains of fly that were overexpressed, downregulated or absent. The activity of the large ventrolateral clock neurons in the fruit fly's brain was measured.

The complete image line is an experimental setup for automated measurement of the activity of fruit flies. When it walks back and forth, the sensor records the beam that it emits. A measure of activity is the number of interruptions. Light and temperature are monitored during the measurement.

More information: Anna Katharina Eick et al, The opposing chloride cotransporters KCC and NKCC control locomotor activity in constant light and during long days, Current Biology (2022). DOI: 10.1016/j.cub.2022.01.056 Journal information: Current Biology Provided by Westfälische Wilhelms-Universität Münster Citation: New findings on the internal clock of the fruit fly (2022, March 21) retrieved 21 March 2022 from https://phys.org/news/2022-03-internal-clock-fruit.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.