(1) One of the pair-rule genes (together with hairy and runt) directly activated by gap gene products during the hierarchical cascade of segmentation gene expression.
(2) The gene product of even skipped, which primarily functions as a transcriptional repressor of other pair-rule genes, such as fushi tarazu.
The importance of even skipped in regulating the segment patterning is well founded in a fruit fly embryo. The expression of this gene regulates transcription of fushi tarazu, which then causes expression of Fushi tarazu and Even-skipped in alternating stripes along the embryo.
Mutation in this gene results in even-numbered parasegments missing in the body pattern of the Drosophila larva.
Symbol: eve (gene) and Eve (gene product).
See also: pair-rule gene.