The Eickbush laboratory studies the mechanism of integration, cellular control, and population genetics of mobile elements that insert specifically into the 28S rRNA genes of their hosts. Most of our work focuses on the R2 retrotransposon; elements found in animals as diverse as vertebrates, arthropods, and hydra. Our early biochemical studies of the proteins encoded by R2 revealed a new mechanism of insertion (retrotransposition) in which the element's RNA transcript is directly reverse transcribed using the chromosomal target site as primer. A large family of mobile elements, the non-LTR retrotransposons, is now thought to use this Target Primed Reverse Transcription (TPRT) mechanism. Non-LTR retrotransposon insertions have had dramatic effects on the evolution and current functioning of eukaryotic genomes. For example, the TPRT mechanism has been estimated to account for 40% of the DNA in the human genome.
Eickbush, T.H. and D.G. Eickbush, D.G.2007. Finely orchestrated movements: evolution of the ribosomal RNA genes.Genetics175: 477-485.
Ye, J. and T.H. Eickbush.2006. Chromatin structure and transcription of the R1- and R2-inserted rRNA genes of Drosophila melanogaster.Mol Cell Biol 23: 8781-8790.
Averbeck, K.T. and T.H. Eickbush. 2005. Monitoring the mode and tempo of concerted evolution in the Drosophila melanogaster rDNA locus. Genetics171: 1837-1846.
Zhang, X. and Eickbush, T.H.. 2005. Characterization of active R2 retrotransposition in the rDNA locus of Drosophila simulans. Genetics170: 195-205.
Christensen, S.M. and T.H. Eickbush. 2005. R2 target primed reverse transcription: ordered cleavage and polymerization steps by protein subunits asymmetrically bound to the target DNA. Mol. Cell. Biol25: 6617-6628.
Ye, J., C.E. Perez-Gonzalez, D.G. Eickbush and T.H. Eickbush. 2005. Competition between R1 and R2 retrotransposable elements in the 28S rRNA genes of insects. Cytogenetic Genome Res110: 299-306.