Int. J. Dev. Biol. 52: 933 - 942 (2008)

https://doi.org/10.1387/ijdb.072419yc

Vol 52, Issue 7

The serpin Spn5 is essential for wing expansion in Drosophila melanogaster

Original Article | Published: 1 September 2008

Yves Charron¹, Rime Madani¹, Chantal Combepine¹, Vincent Gajdosik², Yeukuang Hwu³, Giorgio Margaritondo² and Jean-Dominique Vassalli^1,*

¹Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Switzerland, ²School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland and ³Institute of Physics, Academica Sinica, Nankang, Taiwan, ROC.

Abstract

Serpins, a superfamily of protease inhibitors, control proteolytic cascades in many physiological processes. Genomic studies have revealed the presence of a high number of serpin-encoding genes in Drosophila melanogaster, but their functions remain largely unknown. In a biochemical screen designed to detect protease inhibitors that may be implicated in early Drosophila development, we identified in embryos a ligand that forms a 67 kDa SDS-stable complex with the broad spectrum protease trypsin. Characterization of this ligand revealed it to be the recently described serpin, Spn5. Expression analysis by in situ and Northern blot hybridization indicated maternal transmission of the transcript as well as zygotic expression in many larval, pupal and adult tissues. Targeted repression by RNA interference did not alter early embryogenesis but resulted in a complete defect in the unfolding and expansion of the wings of freshly eclosed mutant flies, without other detectable effects on development.

Keywords

Spn5, serpin, Drosophila, embryo, wing expansion