Programmed cell death and stem cell differentiation are responsible for midgut replacement in Heliothis virescens during prepupal instar.
We have analyzed midgut development during the fifth larval instar in the tobacco budworm Heliothis virescens. In prepupae, the midgut formed during larval instars undergoes a complete renewal process. This drastic remodeling of the alimentary canal involves the destruction of the old cells by programmed cell-death mechanisms (autophagy and apoptosis). Massive proliferation and differentiation of regenerative stem cells take place at the end of the fifth instar and give rise to a new fully functioning epithelium that is capable of digesting and absorbing nutrients and that is maintained throughout the subsequent pupal stage. Midgut replacement in H. virescens is achieved by a balance between this active proliferation process and cell-death mechanisms and is different from similar processes characterized in other insects.
Department of Structural and Functional Biology, University of Insubria, Via J.H. Dunant 3, 21100, Varese, Italy. gianluca.tettamanti@uninsubria.it
Gianluca
G
Tettamanti
Annalisa
A
Grimaldi
Morena
M
Casartelli
Elena
E
Ambrosetti
Benedetta
B
Ponti
Terenzio
T
Congiu
Roberto
R
Ferrarese
Maria Luisa
ML
Rivas-Pena
Francesco
F
Pennacchio
Magda de
Md
Eguileor
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001343:Autophagy / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology*; D004847:Epithelial Cells / Q000502:physiology / Q000648:ultrastructure; D041981:Gastrointestinal Tract / Q000254:growth & development* / Q000648:ultrastructure; D007814:Larva / Q000254:growth & development* / Q000648:ultrastructure; D007915:Lepidoptera / Q000254:growth & development* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D012038:Regeneration / Q000502:physiology; D013234:Stem Cells / Q000502:physiology* / Q000648:ultrastructure