title: Dpp-expressing and non-expressing cells: two different populations of growing cells in Drosophila.
abstract: There are different models that explain growth during development. One model is based on insect and amphibian regeneration studies. This model proposes that growth is directed by pattern, and growth takes place by intercalation at a growth discontinuity; therefore, proliferation should surround the discontinuity. Currently, this model, apart from regenerative studies on mostly adult patterning, has not found supporting evidence in Drosophila that shows proliferation surrounding a discontinuity. Despite this lack of evidence, the importance of discontinuities has been shown in different experiments, even under wt conditions, more specifically in the formation of the leg joints because of the occurrence of cell death at their boundaries. Here, we show the existence of a sharp discontinuity in Decapentaplegic (Dpp) in the genital discs at the third larvae stage (L3), which determines the upregulation in the Jun-NH2-Terminal-Kinase (JNK) pathway, reaper (rpr), head involution defective (hid) and active caspases from its boundaries. The proliferation and cell death surrounding the discontinuity suggest that growth can proceed by intercalation and competitive death takes place in this area. Finally, we show that the Rpr, Grim and Hid (RGH) products are a few of the factors that define the growth discontinuity because they are negative regulators of growth, a new function that is unique from their known functions in apoptosis.
authors: Departamento de Fisiología, Cátedra de "Genética" Facultad de Ciencias Exactas Físicas y Naturales de la Universidad Nacional de Córdoba, Córdoba, Argentina.
authors: Carolina
authors: C
authors: Arias
authors: Departamento de Fisiología, Cátedra de "Genética" Facultad de Ciencias Exactas Físicas y Naturales de la Universidad Nacional de Córdoba, Córdoba, Argentina.
authors: Gimena
authors: G
authors: Fussero
authors: Departamento de Fisiología, Cátedra de "Genética" Facultad de Ciencias Exactas Físicas y Naturales de la Universidad Nacional de Córdoba, Córdoba, Argentina.
authors: Marcelo
authors: M
authors: Zacharonok
authors: Departamento de Fisiología, Cátedra de "Genética" Facultad de Ciencias Exactas Físicas y Naturales de la Universidad Nacional de Córdoba, Córdoba, Argentina.
authors: Ana
authors: A
authors: Macías
mesh_terms: D000818:Animals; D017209:Apoptosis; D004330:Drosophila / Q000166:cytology / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D020935:MAP Kinase Signaling System; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C108880:HID protein, Drosophila; D009479:Neuropeptides; C064196:dpp protein, Drosophila; C108881:grim protein, Drosophila; C086973:rpr protein, Drosophila