Interaction of Telomeric Retroelement HeT-A Transcripts and Their Protein Product Gag in Early Embryogenesis of Drosophila.

The telomere is a nucleoprotein complex at the ends of linear chromosomes that protects them from fusion and degradation. The telomere consists of telomeric DNA, a protective protein complex and telomeric RNA. Biogenesis of telomeric transcripts in development is still far from being understood. Drosophila telomeres are elongated by a transposition of specialized telomeric retrotransposons that encode proteins. Using transgenic constructs encoding tagged telomeric protein, we found that transcripts of Drosophila telomeric element HeT-A bind Gag-HeT-A protein encoded by these transcripts. Maternal HeT-A transcripts and Gag-HeT-A form ribonucleoprotein granules around centrosomes, centers of microtubule organization, during blastoderm formation, upon disruption of telomere silencing during oogenesis. The specific localization of HeT-A RNA is dependent on microtubules since disruption of microtubules caused delocalization of HeT-A transcripts. This transgenic system is a valuable model for the study of telomeric RNA biogenesis.