title: Cell death and tissue reorganization in Rhynchosciara americana (Sciaridae: Diptera) metamorphosis and their relation to molting hormone titers.
abstract: Programmed cell death (PCD) is a focal topic for understanding processes underlying metamorphosis in insects, especially so in holometabolous orders. During adult morphogenesis it allows for the elimination of larva-specific tissues and the reorganization of others for their functionalities in adult life. In Rhynchosciara, this PCD process could be classified as autophagic cell death, yet the expression of apoptosis-related genes and certain morphological aspects suggest that processes, autophagy and apoptosis may be involved. Aiming to reveal the morphological changes that salivary gland and fat body cells undergo during metamorphosis we conducted microscopy analyses to detect chromatin condensation and fragmentation, as well as alterations in the cytoplasm of late pupal tissues of Rhynchosciara americana. Transmission electron microscopy and confocal microscopy revealed cells in variable stages of death. By analyzing the morphological structure of the salivary gland we observed the presence of cells with autophagic vacuoles and apoptotic bodies and DNA fragmentation was confirmed with the TUNEL assay in salivary gland. The reorganization of fat body occurs with discrete detection of cell death by TUNEL assay. However, both salivary gland histolysis and fat body reorganization occur under control of the hormone ecdysone.
authors.affiliation: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, Ed Biomédicas 1, CEP 05508-000 São Paulo, SP, Brazil; Post-Graduate Interunits Program in Biotechnology, Av. Prof. Lineu Prestes, 2415 Edifício ICB - III - Cidade Universitária, CEP 05508-900 São Paulo, SP, Brazil. Electronic address: amsbrandao@gmail.com.
authors.forename: Amanda Dos Santos
authors.initials: Ados S
authors.lastname: Brandão
authors.affiliation: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, Ed Biomédicas 1, CEP 05508-000 São Paulo, SP, Brazil. Electronic address: amaraljb@gmail.com.
authors.forename: Jônatas Bussador
authors.initials: JB
authors.lastname: do Amaral
authors.affiliation: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, Ed Biomédicas 1, CEP 05508-000 São Paulo, SP, Brazil. Electronic address: paularez@gmail.com.
authors.forename: Paula
authors.initials: P
authors.lastname: Rezende-Teixeira
authors.affiliation: Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes 3900, CEP 14049-900 Ribeirão Preto, SP, Brazil. Electronic address: klaus@fmrp.usp.br.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hartfelder
authors.affiliation: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, Ed Biomédicas 1, CEP 05508-000 São Paulo, SP, Brazil. Electronic address: fsiviero@usp.br.
authors.forename: Fábio
authors.initials: F
authors.lastname: Siviero
authors.affiliation: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, Ed Biomédicas 1, CEP 05508-000 São Paulo, SP, Brazil. Electronic address: gmmsante@usp.br.
authors.forename: Gláucia Maria
authors.initials: GM
authors.lastname: Machado-Santelli
mesh_terms: D000818:Animals; D017209:Apoptosis; D001343:Autophagy; D004175:Diptera / Q000254:growth & development* / Q000648:ultrastructure; D005216:Fat Body / Q000254:growth & development / Q000648:ultrastructure; D020287:In Situ Nick-End Labeling; D007301:Insect Hormones / Q000378:metabolism; D007814:Larva / Q000254:growth & development / Q000648:ultrastructure; D008675:Metamorphosis, Biological; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D011679:Pupa / Q000254:growth & development / Q000648:ultrastructure; D012469:Salivary Glands / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D007301:Insect Hormones
keywords: Apoptosis; Autophagy; Fat body; Postembryonic development; Salivary gland