In the fruit fly Drosophila, the functions of the three enzymes Tan, Ebony and Black are closely intertwined - among other things they are involved in neurotransmitter recycling for the visual process. RUB researchers from the Department of Biochemistry showed for the first time that flies cannot see without this recycling. Their analysis of the enzyme Black also raises new questions as to its function. Anna Ziegler, Florian Brsselbach and Bernhard Hovemann report in the Journal of Comparative Neurology", which chose this topic as cover story.
Tan, Ebony and Black are important for the visual process and the formation of the cuticle
The fruit fly's genes tan, ebony and black contain the construction plans for three enzymes with the same names that work together in hardening the outer shell of the body, the cuticle. The same enzymes also occur in the compound eye of the fly. Researchers therefore assume that Tan, Ebony and Black work together in vision - similar to the way they do in the formation of the cuticle. In fact, flies with mutations of the ebony and tan genes cannot see. A mutation of the black gene, however, has no such effect. Prof. Hovemann's team examined where the enzyme Black appears in the compound eye and the role it plays in vision.
Black and Ebony always occur together
First, the scientists tested where the genes ebony and black are active in the compound eye of the fruit fly and in its extra eyes on the head, the ocelli. They put different types of light-sensitive cells called photoreceptors, under the microscope. The result: both genes are always read together - just like in the cuticle. This suggests that the functions of the enzymes Ebony and Black are closely linked.
Vision requires a continuous flow of the neurotransmitter histamine
When light falls into the compound eye, the photoreceptors release the neurotransmitter hista
|Contact: Bernhard Hovemann|