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.
Tettamanti
Gianluca
G
Department of Structural and Functional Biology, University of Insubria, Via J.H. Dunant 3, 21100, Varese, Italy. gianluca.tettamanti@uninsubria.it
Grimaldi
Annalisa
A
Casartelli
Morena
M
Ambrosetti
Elena
E
Ponti
Benedetta
B
Congiu
Terenzio
T
Ferrarese
Roberto
R
Rivas-Pena
Maria Luisa
ML
Pennacchio
Francesco
F
Eguileor
Magda de
Md
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