title: Proliferation and differentiation of intestinal stem cells during metamorphosis of the red flour beetle, Tribolium castaneum.
abstract: The insect midgut epithelium is remodeled during larval-pupal metamorphosis when larval polyploid cells (LPCs) are replaced by the daughters of intestinal stem cells (ISCs). We characterized the proliferation of ISCs during midgut remodeling in the red flour beetle, Tribolium castaneum. Midgut remodeling is initiated at 96 hr after ecdysis into the final instar larval stage. Immunocytochemistry with bromodeoxyuridine and phospho-histone H3 antibodies showed that the ISCs are the progenitors of the pupal/adult midgut epithelium and they undergo proliferation and differentiation to form new midgut epithelium. In vitro midgut culture experiments revealed that 20-hydroxyecdysone (20E) in the absence of juvenile hormone induces proliferation of ISCs. RNA interference (RNAi) mediated silencing of ecdysone receptors (EcRA and EcRB) and ultraspiracle (USP) identified EcRA and USP but not EcRB as the proteins involved in 20E regulation of ISCs proliferation. These data show that the proliferation of ISCs is under both developmental and endocrine regulation.
authors.affiliation: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky 40546, USA.
authors.forename: R
authors.initials: R
authors.lastname: Parthasarathy
authors.forename: Subba R
authors.initials: SR
authors.lastname: Palli
mesh_terms: D000818:Animals; D016923:Cell Death / Q000502:physiology; D002454:Cell Differentiation; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins; D004441:Ecdysterone / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007422:Intestines / Q000166:cytology / Q000196:embryology / Q000254:growth & development; D007814:Larva / Q000033:anatomy & histology / Q000502:physiology; D008675:Metamorphosis, Biological; D011679:Pupa / Q000033:anatomy & histology / Q000502:physiology; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014231:Tribolium / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D012333:RNA, Messenger; D011987:Receptors, Steroid; D012717:Sesquiterpenes; D014157:Transcription Factors; C066030:USP protein, Drosophila; C467903:ecdysone receptor A, insect; D004441:Ecdysterone; C036585:juvenile hormone III