The elimination of an adult segment by the Hox gene Abdominal-B

Hox gene activity leads to morphological diversity of organs or structures in different species. One special case of Hox function is the elimination of a particular structure. The Abdominal-B Hox gene of Drosophila melanogaster provides an example of such activity, as this gene suppresses the formation of the seventh abdominal segment in the adult. This elimination occurs only in males, and is characteristic of more advanced Diptera. The elimination requires the differential expression or activity of genes that are downstream Abdominal-B, or that work togetherwith it, andwhich regulate cell proliferation or cell extrusion. Here,we reviewthe mechanisms responsible for such elimination and provide some new data on processes taking place within this segment. © 2015 Elsevier Ireland Ltd. All rights reserved.Ministerio de Economía y Competitividad (BFU2008-00632 and BFU2011-26075), the Consolider Program (CSD2007-0008) and an Institutional Grant from the Ramon Areces FoundationPeer Reviewe