Both JNK and apoptosis pathways regulate growth and terminalia rotation during Drosophila genital disc development

BENITEZ, SERGIO; SOSA, CLAUDIA; TOMASINI, NICOLÁS; MACÍAS, ANA

INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY

U B C PRESS

Año: 2010 vol. 54 p. 643 - 653

0214-6282

Apoptosis is necessary for the regulation of growth during development, but theprecise details of this regulation have not been completely characterized. In this study, we usedthe Drosophila genital disc as a model to analyze the contribution of apoptosis to growthregulation. We studied the expression or activity of several elements of the apoptotic deathpathway such as Drosophila inhibitor of apoptosis1, caspases, the apoptotic genes reaper (rpr)and head involution defective, as well as elements of the Jun-NH2-terminal kinase (JNK) pathway.We found that the JNK pathway is active in a dynamic, asymmetric and genitalia-specific manner.Apoptosis, as measured in terms of the expression of a variety of apoptotic molecules, occurs ina JNK-dependent and -independent manner and was detected among engrailed (en) expressingcells. JNK regulation of apoptotic genes is necessary to control growth in both sexes and rotationin males; this regulatory role is necessary to execute en+ cell death and to activate expression ofrpr in these cells. rpr is up-regulated at antero-posterior borders, and this expression appears tobe of particular importance in the control of growth, since the balance between cell proliferationand death in those regions appears to depend on the equilibrium between pro- and anti-apoptoticfactors at a cellular level.