title: Midgut epithelium in molting silkworm: A fine balance among cell growth, differentiation, and survival.
abstract: The midgut of insects has attracted great attention as a system for studying intestinal stem cells (ISCs) as well as cell death-related processes, such as apoptosis and autophagy. Among insects, Lepidoptera represent a good model to analyze these cells and processes. In particular, larva-larva molting is an interesting developmental phase since the larva must deal with nutrient starvation and its organs are subjected to rearrangements due to proliferation and differentiation events. Several studies have analyzed ISCs in vitro and characterized key factors involved in their division and differentiation during molt. However, in vivo studies performed during larva-larva transition on these cells, and on the whole midgut epithelium, are fragmentary. In the present study, we analyzed the larval midgut epithelium of the silkworm, Bombyx mori, during larva-larva molting, focusing our attention on ISCs. Moreover, we investigated the metabolic changes that occur in the epithelium and evaluated the intervention of autophagy. Our data on ISCs proliferation and differentiation, autophagy activation, and metabolic and functional activities of the midgut cells shed light on the complexity of this organ during the molting phase.
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Franzetti
authors.affiliation: Department of Biosciences, University of Milano, 20133 Milano, Italy.
authors.forename: Morena
authors.initials: M
authors.lastname: Casartelli
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: D'Antona
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
authors.forename: Aurora
authors.initials: A
authors.lastname: Montali
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Romanelli
authors.affiliation: CREA - Honey Bee and Silkworm Research Unit, Padua Seat, 35143 Padova, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Cappellozza
authors.affiliation: Department of Biosciences, University of Milano, 20133 Milano, Italy; Department of Agricultural Sciences, University of Napoli Federico II, 80055 Portici, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Caccia
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Grimaldi
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
authors.forename: Magda
authors.initials: M
authors.lastname: de Eguileor
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy. Electronic address: gianluca.tettamanti@uninsubria.it.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Tettamanti
mesh_terms: D000818:Animals; D001343:Autophagy; D012831:Bombyx / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D002454:Cell Differentiation; D049109:Cell Proliferation; D004064:Digestive System / Q000033:anatomy & histology / Q000254:growth & development / Q000648:ultrastructure; D004848:Epithelium / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D007814:Larva / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D018978:Molting; D013234:Stem Cells / Q000502:physiology*
keywords: Autophagy; Insect midgut; Intestinal stem cells (ISCs); Lepidoptera; Molt