title: Early Distal-less expression in a developing crustacean limb bud becomes restricted to setal-forming cells.
abstract: Distal-less (Dll) plays a well-known role in patterning the distal limb in arthropods. However, in some taxa, its expression even during early limb development is not always limited to the distal limb. Here, I trace the expression of Distal-less in a crustacean (Thamnocephalus platyurus) from the early limb bud to later stages of limb development, a period that includes differentiation of juvenile and adult morphology. During early development, I find two distinct types of DLL expression: one correlated with proximal distal leg patterning and the other restricted to setal-forming cells. Later in development, all the DLL expression is restricted to setal-forming cells. Based on the particular cells expressing DLL, I hypothesize an ancestral role for Dll function in the formation accessory cells of sensilla.
authors.affiliation: Department of Ecology and Evolutionary Biology, Yale University, PO Box 208106, 165 Prospect St., New Haven, CT 06520, USA. terri.williams@yale.edu
authors.forename: Terri A
authors.initials: TA
authors.lastname: Williams
mesh_terms: D000818:Animals; D033202:Anostraca / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D001156:Artemia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D019521:Body Patterning / Q000235:genetics; D002454:Cell Differentiation; D047108:Embryonic Development / Q000235:genetics; D005121:Extremities / Q000033:anatomy & histology / Q000254:growth & development; D018398:Homeodomain Proteins / Q000378:metabolism*; D007814:Larva / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D018878:Limb Buds / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins