title: A molecular view of onychophoran segmentation.
abstract: This paper summarizes our current knowledge on the expression and assumed function of Drosophila and (other) arthropod segmentation gene orthologs in Onychophora, a closely related outgroup to Arthropoda. This includes orthologs of the so-called Drosophila segmentation gene cascade including the Hox genes, as well as other genetic factors and pathways involved in non-drosophilid arthropods. Open questions about and around the topic are addressed, such as the definition of segments in onychophorans, the unclear regulation of conserved expression patterns downstream of non-conserved factors, and the potential role of mesodermal patterning in onychophoran segmentation.
authors.affiliation: Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, 75236 Uppsala, Sweden. Electronic address: ralf.janssen@geo.uu.se.
authors.forename: Ralf
authors.initials: R
authors.lastname: Janssen
mesh_terms: D000818:Animals; D001181:Arthropods / Q000033:anatomy & histology* / Q000196:embryology / Q000235:genetics*; D019521:Body Patterning / Q000235:genetics*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000196:embryology / Q000235:genetics; D018507:Gene Expression Regulation, Developmental
keywords: Development; Euperipatoides; Onychophora; Segmentation