Christopher Hernandez

Christopher Hernandez
Year: 2013

Epigenetic Regulation of Sadhu Transposable Elements in Arabidopsis thaliana

Studies exploring natural variation of the Arabidopsis transcriptome uncovered a family of retrotransponsons, dubbed Sadhu elements, which show genetic and epigenetic variation among different accessions. Several of these elements have been further characterized and appear to be meiotically stable “epialleles,” epigenetic alleles that differ only in cytosine methylation state and thus expression state. In this study, the knowledge of epigenetic variation in Sadhu elements was further explored by investigating potential developmental regulation of epigenetic silencing. Both endpoint and quantitative RT-PCR were used to determine whether the epigenetic state of Sadhu elements vary between tissue types in two standard wild-type strains: the Col and Ler accessions. In addition, public datasets in the Sequence Read Archive (, a depository for next-generation sequencing data, were mined to determine whether various abiotic stresses affected the expression of Sadhu elements and to confirm tissue expression findings. Many retrotransposons are reputedly under epigenetic regulation and have been implicated in playing important roles in stress adaptation and evolution. Our study contributes to knowledge of both retrotransposon regulation and epiallele stability by investigating the expression of Sadhu elements in different tissues and under stress.

My Experience

As part of the PGRP program, I was provided with the opportunity to work on cutting edge plant biology research in an unintimidating, welcoming environment. Weekly seminars provided by the program were both interesting and informative. In addition to lab related activities, plenty of opportunities were available to explore the Ithaca community. Overall, my summer at BTI has cemented my interest in research and has instilled me with confidence as I move forward towards graduate school.