Professor & HHMI Investigator
Ph.D., Cambridge University, 1986
firstname.lastname@example.org | (516) 367-8322
Chromosomes are covered with chemical modifications that help control gene expression. I study this secondary genetic code - the epigenome - and how it is guided by small mobile RNAs in plants and fission yeast. Our discoveries impact plant breeding and human health, and we use this and other genomic information to improve aquatic plants as a source of bioenergy.
Epigenetic mechanisms of gene regulation—chemical and conformational changes to DNA and the chromatin that bundles it—have had an important impact on genome organization and inheritance and on cell fate. These mechanisms are conserved in eukaryotes and provide an additional layer of information superimposed on the genetic code. Robert Martienssen, a pioneer in the study of epigenetics, investigates mechanisms involved in gene regulation and stem cell fate in yeast and model plants including Arabidopsis and maize. He and his colleagues have shed light on a phenomenon called position-effect variegation, caused by inactivation of a gene positioned near densely packed chromosomal material called heterochromatin. They have discovered that small RNA molecules arising from repeating genetic sequences program that heterochromatin. Martienssen and colleagues have described a remarkable process by which “companion cells” to sperm in plant pollen grains provide them with instructions that protect sperm DNA from transposon damage. They found that some of these instructions, or epigenetic marks, could be inherited in the next generation. These marks, and the small RNA responsible that guide them, can sense the number of chromosomes inherited from pollen and may allow Arabidopsis, a flowering plant, to produce egg cells without meiosis, an important step toward a long-time goal of plant breeding: generating clonal offspring to perpetuate hybrid vigor. The lab has also shown that when RNA polymerase II has transcribed a stretch of DNA, the RNA interference mechanism causes the enzyme to release its hold on the DNA and fall away. This allows the replication fork to progress smoothly and the DNA strands to be copied; histone-modifying proteins, which follow right along, establish heterochromatin. Martienssen’s group also continues to work on problems related to the creation of plant-based biofuels. As part of a collaborative project to generate a high-quality full genome map of the oil palm plant, Martienssen and his colleagues identified a transposon whose modification controls the yield of oil palm trees. This discovery will increase yields and should lessen the environmental burden of oil palm production, which often threatens already endangered rainforest lands.
An essay from the President: Biology for the planet
May 16, 2019
CSHL plant scientists are looking for solutions to the biggest questions in agriculture as environments are reshaped by climate change.
Andrea Schorn zooms in on small RNAs in the cell
April 29, 2019
Dr. Andrea Schorn joins CSHL faculty as research assistant professor. Her focus is exploring transposable elements in the genome of mammalian cells.
Rob Martienssen wins Martin Gibbs Medal for plant research
April 15, 2019
CSHL Professor Rob Martienssen wins the 2019 Martin Gibbs Medal for his contributions to plant biology.
Big plans for a tiny plant
July 15, 2018
On this episode of Base Pairs, Rob Martienssen discusses how duckweed could be the next biofuel and help combat climate change
A science writer’s quest to understand heredity
May 30, 2018
LabDish spoke with science writer Carl Zimmer about what he learned about heredity as he zig-zagged through CSHL while writing his new book.
CSHL’s Rob Martienssen honored with prestigious Barbara McClintock Prize
January 19, 2018
Plant geneticist Rob Martienssen awarded prestigious McClintock Prize.
Counting chromosomes: Plant scientists solve a century-old mystery about reproduction
January 18, 2018
Geneticists have solved a century-old mystery by discovering a remarkable mechanism that enables plants to count their chromosomes
Newly identified small RNA fragments defend the genome when it’s ‘naked’
June 29, 2017
Fragments snipped from tRNAs protect embryonic stem cells while they’re being epigenetically reprogrammed.
Focus on quiescent cells brings to light the essential role of RNA interference in transcription control
November 9, 2016
RNAi and other epigenetic processes induce changes in where and when specific genes are expressed without altering their genetic code.
5th Graders spend a day as young scientists
December 16, 2015
Students from the West Side Elementary School learn about the history and workings of Cold Spring Harbor Laboratory.
Zaratiegui, B. M. and Vaughn, M. W. and Irvine, D. V. and Goto, D. and Watt, S. and Bahler, J. and Arcangioli, B. and Martienssen, R. A. (2011) CENP-B preserves genome integrity at replication forks paused by retrotransposon LTR. Nature, 469(7328) pp. 112-5.
Slotkin, R. K. and Vaughn, M. and Borges, F. and Tanurdzic, M. and Becker, J. D. and Feijo, J. A. and Martienssen, R. A. (2009) Epigenetic reprogramming and small RNA silencing of transposable elements in pollen. Cell, 136(3) pp. 461-72.
Irvine, D. V. and Zaratiegui, Mi. and Tolia, N. H. and Goto, D. B. and Chitwood, D. H. and Vaughn, M. W. and Joshua-Tor, L. and Martienssen, R. A. (2006) Argonaute slicing is required for heterochromatic silencing and spreading. Science, 313(5790) pp. 1134-7.
Lippman, Z. and Gendrel, A. V. and Black, M. and Vaughn, M. W. and Dedhia, N. and McCombie, W. R. and Lavine, K. and Mittal, V. and May, B. and Kasschau, K. D. and Carrington, J. C. and Doerge, R. W. and Colot, V. and Martienssen, R. (2004) Role of transposable elements in heterochromatin and epigenetic control. Nature, 430(6998) pp. 471-6.
Kidner, C. A. and Martienssen, R. A. (2004) Spatially restricted microRNA directs leaf polarity through ARGONAUTE1. Nature, 428(6978) pp. 81-4.Additional materials of the author at
CSHL Institutional Repository