Krüppel

Krüppel is a gap gene in Drosophila melanogaster, located on the 2R chromosome, which encodes a zinc finger C2H2 transcription factor.

Human homologs of Krüppel are collectively named Krüppel-like factors, a set of proteins well characterized for their role in carcinogenesis.

This results in Krüppel being expressed in a stripe in the center of the embryo's A-P axis, where Hunchback concentration has dropped to a low enough level so that it can act as an activator, but Knirps is not yet present to inhibit.

[16][17] The expression patterns of pair rule gene will in turn regulate the segment polarity genes, making Krüppel essential for proper development along the anterior posterior axis and segment identity.

Krüppel has shown homology to the mammalian Krüppel-like factors, which play key biological roles in the pathogenesis of many human diseases: cancer,[18] obesity,[19] inflammatory disorders[20] and cardiovascular complications.

In situ hybridization against mRNA of the gap genes knirps, Krüppel and giant in the Drosophila melanogaster early embryo. Panels also show how these genes are affected by the mutation brakeless (bks).