Principal Investigator


Dorothy Shippen
Phone:(979) 862-2342

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B.S. Auburn University (1982)

Ph.D. University of Alabama, Birmingham (1987)

Postdoc. University of California, Berkeley and University of California, San Francisco (1987-91)

Joined Texas A&M in 1991

Current Lab Members

 Post Doctoral Associates

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Behailu Aklilu

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Ph.D. (Genetics), 2015, University of New Hampshire, USA

M.Sc. (Agriculture and Biotechnology), 2008, Ben-Gurion University, Israel

B.Sc. (Plant Sciences), 2002, Haromaya University, Ethiopia

Research Assistant (2008-2009), Ben-Gurion University of the Negev Research Assistant (2003-2006), Ethiopian Institute of Agricultural Research

Research Interest:

The ends of eukaryotic linear chromosomes are capped by nucleoprotein structures called telomeres, which protect the termini from progressive chromosome shortening and the DNA damage response pathway. In the flowering plant, Arabidopsis thaliana, telomeres are bound by telomere specific ssDNA-binding protein complex, CST (CTC1/STN1/TEN1). The CST complex functions in both end protection and telomere replication through interactions with various proteins. In A. thaliana, it is proposed that CST engages both telomerase and DNA polymerase α (Polα) to promote G- and C-strand synthesis, respectively. My research is to investigate the dynamic in vivo interactions of CST with end protection and replication complexes. Other research interests of mine are investigating the role of A. thaliana Replication Protein A (RPA) in telomere maintenance; and Telomerase RNA Subunit 2 (TER2) in meiotic progression.

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Claudia Marcela Castillo-Gonzalez

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B.Sc. Microbiology - Minor in Chemistry, Universidad de Los Andes, Bogota D.C., Colombia (2005)

M.Sc. Microbiology, Universidad de Los Andes, Bogotá D.C., Colombia (2007)

Research Assistant, Universidad de São Paulo, São Paulo, Brazil (2009)

Ph.D. Biochemistry, Texas A&M University, College Station, Texas, USA (2017)

Post Doctoral Research Associate, Texas A&M University, College Station, Texas, USA (present) )

Research Interests:

Of the features that define a living organism, resilience is perhaps my favorite. I am deeply interested in the crosstalk of regulatory networks and chromatin modification, as means to inherit adaptive environmental information. Telomeres are the terminal structures of eukaryotic linear chromosomes, essential for maintaining genetic stability and widely regarded as the key to cell immortality. Protection of Telomeres 1(POT1) is a fundamental component of the telomere sheltering complex in mammals, whose role is to prevent the targeting of chromosome ends by the DNA repair pathway, and to modulate telomerase activity. Arabidopsis thaliana encodes three paralogs of the POT1 gene. While POT1a functions as mammalian POT1, the roles of POT1b and POT1c remain elusive. Previous work from our lab showed that POT1b acts as a negative regulator of telomerase activity, but its effect on telomere length is negligible in vivo. Loss-of-function pot1b mutants display a worsening phenotype after multiple generations, consisting of delayed development, decreased fitness, and hypersensitivity to DNA damage. We hypothesize that duplication of the POT1 gene in Arabidopsis has enabled the acquisition of specialized, non-canonical functions in POT1b. My research goal is to understand the roles of POT1b through the identification and characterization of its macromolecular complexes upon environmental stimuli.


Pierce Young

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Ph.D. Biochemistry and Cell Biology - Rice University (2018)

B.S. Plant and Environmental Soil Science - Texas A&M University (2012)

Research Interest:

Telomere length varies considerably among different wild-type accession of Arabidopsis thaliana. I am interested in understanding the molecular basis for the observed differences in telomere length. I am currently investigating the function of the rRNA methyltransferase NOP2a, which was identified as a candidate gene involved in establishing long telomeres in a particular accession of Arabidopsis thaliana. I am also utilizing natural variation in telomere lengths to identify additional novel genes responsible for telomere length establishment.

Graduate Students

Sreyashree Bose

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B.Tech (Major : Biotechnology) from West Bengal University of Technology, India (2010 - 2014)

Pursuing Ph.D. at Dept. of Biochemistry and Biophysics Texas A & M University, College Station, Texas (2014-present)

Research Interests:

Research from this lab has led to identification of three different types of RNA molecules which are involved in Telomere Biology and they are TER1, TER2 and TER2s. Among these TER2 has been seen to negatively regulate the activity of Telomerase Enzyme. Further research has shown that TER2 levels may be tuned under conditions of DNA damage indicating at the possible role of TER2 in regulating Telomerase under conditions of DNA damage. I am currently investigating the regulation of TER2 using biochemical and genetic approaches. I am also interested in studying about the pathway involved biogenesis of TER2 and involvement of TER2 in the growth and development of Arabidopsis thaliana.

Borja Barbero

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B.S in biochemistry - University of Delaware (2015)

Pursuing Ph.D at Dept. of Biochemistry and Biophysics, Texas A&M University, College Station, Texas (2015- present)

Research Interest:

Identification of function of POT1b in Arabidopsis thaliana. In humans, POT1 contributes to capping and recruitment of telomerase. Arabidopsis thaliana has evolved different POT1 genes, with different functions. As well I am interested in studying a possible collaboration between TEN1 and TER2 in the negative regulation of telomerase of Arabidopsis thaliana. A question that has intrigued me since I started working in the Shippen lab has been what recruits telomerase in arabidopsis

Jiarui Song (Gerry)

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B.S in Shandong University, China (2015)

Pursuing Ph.D. at Dept. of Biochemistry and Biophysics, Texas A and M University, College Station, Texas (2015-present)

Research Interest:

My research focus is to identify a RNA binding protein AtLa1 as a potential component involved in the Arabidopsis TER2 (Telomerase RNA 2) processing. Based on pervious study from this lab, there are three different telomerase RNAs in A. thaliana, and the non-canonical telomerase RNA- TER2 performs as negative regulator of telomerase activity. Further research has shown that AtLa1 can recognize and interact with the specific region of TER2, which suggests the hypothesis that AtLa1 is one missing component of TER2 processing or even TERs regulation. Biochemical and genetic approaches are used for identifying the telomere-related function of AtLa1. The second project is to determine whether another bona fide La protein- AtLa2 involves in the TERs maturation.

Undergraduate students

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Erica Branham

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Pursuing a B.S. in Genetics at Texas A&M University, College Station, TX (Graduation in May 2020)

Research Interest:






Tyler Higbee

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Pursuing a B.S. in Biochemistry and a B.S. in Genetics at Texas A&M University in College Station, TX (Graduating in December of 2019)

Research Interests:

I am currently working on a project to determine the subcellular localization of telomerase during periods of increased oxidative stress in the plant model, Arabidopsis thaliana. These findings may prove useful in determining potential functions of telomerase away from the telomere.






Jennifer Del Bosque

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Pursuing a B.S in Biomedical Sciences at Texas A&M University (Graduation in 2021)

Research Interests:

We are currently working on a project to understand the functions of the AtPOT1b protein. This is done so by performing mutagenesis on these plants to understand the pathway and effects of POT1b.

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Ryan Lynch

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Pursuing a B.S. degree in Biochemistry and Genetics at Texas A&M University (Graduation in May 2020)

Research Interests:

My interest is understanding the function of Replication Protein A (RPA) and its involvement in telomere maintenance. Function of RPA can be determined through genetic and phenotype measures in our model organism, Arabidopsis Thaliana.







Lauren Sampson

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Pursuing a B.S in Biochemistry at Texas A&M University (Graduation in 2020)

Research Interest:

Howdy! My research goal is to understand the function of Replication Protein A (RPA) in telomere maintenance in the research model organism, Arabidopsis thaliana. We know that RPA plays roles in DNA repair and replication, but its impact on telomere biology of higher eukaryotes is currently not clearly defined. Using reverse genetics, molecular biology, and biochemical studies, we hope to better understand the role RPA plays in telomere maintenance.






Sefanit Rezene

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B.S. Biochemistry, B.S. Genetics (Graduation in May 2021)

Research Interest:

My current research focus is to identify the function of a telomere associated protein, POT1b, in Arabidopsis thaliana. Preliminary data suggest that POT1b may have a function outside telomere biology. Genetic approaches are being used in order to better understand POT1b function.

understand the role RPA plays in telomere maintenance.