A giant called dumpy

Fruit flies have something that we don’t have: they produce a protein called dumpy. This protein is the largest created by insects, and is comparable in size to the largest human protein – titin. While titin is vital for our muscle function, dumpy connects the soft cells of the insect’s body with its tough, waterproof shell – the cuticle.

Today’s Picture of the Week was taken by Daniel Rios from the Leptin group at EMBL Heidelberg. It shows a magnification of the peeled pupae of a fruit fly (Drosophila melanogaster). The blue colour shows the dumpy protein, covering almost the entire surface of the fly. In the top right corner, the eye of the insect is visible, also covered by the protein. The red dots correspond to tendon cells.

The gene that encodes dumpy breaks all records: it spans over 100 000 base pairs – the “letters” that make up our genetic code. This large gene encodes the information for the approximately 20 000 amino acids that dumpy is composed of. By comparison, human titin is composed of 34 000 amino acids.