We are taking biochemical, molecular genetic and cytological approaches to study the structure, function and maintenance of telomeres. Telomeres are higher order nucleoprotein complexes that cap the ends of eukaryotic chromosomes and play essential roles in conferring genome stability and cell proliferation capacity. The protective cap of the telomere is comprised of specific telomere binding proteins that regulate the length of telomeric DNA tract and allow the cell distinguish the chromosome terminus from a double-strand break. Telomeric DNA is synthesized by the action of telomerase, an unusual reverse transcriptase that replenishes telomeric DNA lost as a consequence of replication by conventional DNA polymerases. We have developed the genetically tractable flowering plant Arabidopsis thaliana as a model system for studying telomeres in higher eukaryotes. With its sequenced genome, abundant genetic and transgenic tools, and extraordinarily high tolerance to genome instability, Arabidopsis has proven to be an excellent model for investigating fundamental processes in telomere biology. Current studies focus on defining the function and molecular evolution of telomere capping proteins and components of the telomerase ribonucleoprotein complex.

selected publications
Academic Articles87
  • Song, J., Castillo-González, C., Ma, Z., & Shippen, D. E. (2021). Arabidopsis retains vertebrate-type telomerase accessory proteins via a plant-specific assembly. 49(16), gkab699--9507.
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  • Choi, J. Y., Abdulkina, L. R., Yin, J., Chastukhina, I. B., Lovell, J. T., Agabekian, I. A., ... Purugganan, M. D. (2021). Natural variation in plant telomere length is associated with flowering time. 33(4), koab022--1134.
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  • Campitelli, B. E., Razzaque, S., Barbero, B., Abdulkina, L. R., Hall, M. H., Shippen, D. E., Juenger, T. E., & Shakirov, E. V. (2021). Plasticity, pleiotropy and fitness tradeoffs in Arabidopsis genotypes with different telomere lengths. (4), 1939-1952.
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  • Castillo-González, C., & Shippen, D. E. (2020). Change and HOAP for the best. 9, e64945.
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  • Bose, S., Suescún, A. V., Song, J., Castillo-González, C., Aklilu, B. B., Branham, E., Lynch, R., & Shippen, D. E. (2020). tRNA ADENOSINE DEAMINASE 3 is required for telomere maintenance in Arabidopsis thaliana. 39(12), 1669-1685.
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  • Nelson, A., Beilstein, M. A., & Shippen, D. E. (2014). Plant Telomeres and Telomerase. Molecular Biology. 25-49. Springer New York.
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  • Nelson, A., Beilstein, M. A., & Shippen, D. E. (2013). Nucleus and Genome: Telomeres. Molecular Biology. 1-21. Springer New York.
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  • Lamb, J. C., Shakirov, E. V., & Shippen, D. E. (2012). Plant Telomeres. Plant Cytogenetics. 143-191. Springer New York.
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Conference Papers3
  • Song, X., Surovtseva, Y. V., Leehy, K., Boltz, K., & Shippen, D. E. (2009). A CST-like complex protects chromosome ends in Arabidopsis. 17(4), 546-546.
  • Melek, M., Greene, E. C., Bednenko, J., & Shippen, D. E. (1996). Telomerase interactions with DNA: Chromosome healing and telomere maintenance.. 7, 983-983.
chaired theses and dissertations
First Name
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mailing address
Texas A&M University; Biochemistry & Biophysics; 2128 TAMU
College Station, TX 77843-2128