Gene Silencing Triggered by Non-LTR Retrotransposons in the Female Germline of Drosophila melanogaster

Corresponding author: Isabelle Busseau, CNRS, 141 rue de la Cardonille, 34396 Montpellier Cedex 5, France., busseau{at}igh.cnrs.fr (E-mail)

Communicating editor: M. J. SIMMONS

Several studies have recently shown that the activity of some eukaryotic transposable elements is sensitive to the presence of homologous transgenes, suggesting the involvement of homology-dependent gene-silencing mechanisms in their regulation. Here we provide data indicating that two non-LTR retrotransposons of Drosophila melanogaster are themselves natural triggers of homology-dependent gene silencing. We show that, in the female germline of D. melanogaster, fragments from the R1 or from the I retrotransposons can mediate silencing of chimeric transcription units into which they are inserted. This silencing is probably mediated by sequence identity with endogenous copies of the retrotransposons because it does not occur with a fragment from the divergent R1 elements of Bombyx mori, and, when a fragment of I is used, it occurs only in females containing functional copies of the I element. This silencing is not accompanied by cosuppression of the endogenous gene homologous to the chimeric transcription unit, which contrasts to some other silencing mechanisms in Drosophila. These observations suggest that in the female germline of D. melanogaster the R1 and I retrotransposons may self-regulate their own activity and their copy number by triggering homology-dependent gene silencing.

This article has been cited by other articles:

				M. Anbar, R. Bracha, Y. Nuchamowitz, Y. Li, A. Florentin, and D. Mirelman Involvement of a Short Interspersed Element in Epigenetic Transcriptional Silencing of the Amoebapore Gene in Entamoeba histolytica Eukaryot. Cell, November 1, 2005; 4(11): 1775 - 1784. [Abstract] [Full Text] [PDF]

				E. Sarot, G. Payen-Groschene, A. Bucheton, and A. Pelisson Evidence for a piwi-Dependent RNA Silencing of the gypsy Endogenous Retrovirus by the Drosophila melanogaster flamenco Gene Genetics, March 1, 2004; 166(3): 1313 - 1321. [Abstract] [Full Text] [PDF]