title: Enforcing biphasic eye development in a directly developing insect by transient knockdown of single eye selector genes.
abstract: The visual system of indirectly developing insects such as Drosophila passes through two phases of development. Larval eyes form in the embryo, whereas the adult compound eyes form during metamorphosis. Comparative evidence implies that this biphasic mode of visual system development evolved from the continuously developing eye of directly developing insects. We investigated the developmental basis of this evolutionary transformation in a directly developing insect taking advantage of the time-limited nature of systemic RNAi in the grasshopper Schistocerca americana. Transient knockdown of the homologs of the early retinal genes eyes absent (eya) or sine oculis (so) both induced long-term arrest of eye development in grasshopper nymphs. Eye development, however, resumed after knockdown expiry. This finding sheds first light on the molecular regulation of postembryonic eye development in directly developing insects and unravels an inherent capacity of the underlying gene regulatory network to accommodate for partitioning visual system development into discrete phases, as in indirectly developing insects.
authors.affiliation: Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.forename: Markus
authors.initials: M
authors.lastname: Friedrich
mesh_terms: D000818:Animals; D054910:Compound Eye, Arthropod / Q000254:growth & development*; D005123:Eye; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D020868:Gene Silencing / Q000502:physiology*; D006110:Grasshoppers / Q000235:genetics / Q000254:growth & development*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007313:Insecta; D009758:Nymph / Q000235:genetics / Q000254:growth & development; D034741:RNA, Small Interfering / Q000235:genetics; D034743:RNA-Induced Silencing Complex / Q000235:genetics
chemical_list: D005136:Eye Proteins; D018398:Homeodomain Proteins; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex