Rob Martienssen
Professor & HHMI Investigator
Ph.D., Cambridge University, 1986
martiens@cshl.edu | (516) 367-8322 (p)
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.
Big plans for a tiny plant
July 15, 2018
As temperatures around the globe continue to rise, scientists are working hard to develop solutions that deal with the consequences of climate change, focusing on ways to slow or halt the trend. One significant hurdle is our dependence on fossil fuels like gasoline, coal, and petroleum. Researchers are working with a variety of biofuels that...
A science writer’s quest to understand heredity
May 30, 2018
LabDish Blog At this very moment, there is more Neanderthal DNA on Earth than there was when Neanderthals were alive. Bits of their DNA, inherited tens of thousands of years ago, persist in many of our genomes today. This astounding legacy is one of many revelations that renowned science writer Carl Zimmer uses to burst...
Public Lecture – ENERGY FROM THIN AIR: Basic research to biofuels
March 2, 2018
Please join us for a free public lecture… ENERGY FROM THIN AIR: Basic research to biofuels Rob Martienssen, Ph.D. Professor, Cold Spring Harbor Laboratory Investigator, HHMI Frank O’Keefe CEO, Infinitree Inc. Come hear the story about plant science, entrepreneurial spirit, and pond scum.
CSHL’s Rob Martienssen honored with prestigious Barbara McClintock Prize
January 19, 2018
Cold Spring Harbor, NY — Rob Martienssen, Professor, HHMI Investigator, and Head of Genomics and Plant Genetics at Cold Spring Harbor Laboratory (CSHL) has received the 2018 Barbara McClintock Prize for Plant Genetics and Genome Studies. The award and medal will be conferred during a ceremony in Saint-Malo, France, on March 24th, as part of...
Counting chromosomes: Plant scientists solve a century-old mystery about reproduction
January 18, 2018
Cold Spring Harbor, NY — Counting is vital in nature. Counting chromosomes is something that most animals, plants and even single-celled organisms need to know how to do to assure viability and to reproduce. Today, a team of geneticists reveals a remarkable mechanism that enables plants to count their chromosomes, solving a century-old mystery. Being...
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 Cold Spring Harbor, NY — Our genomes are minefields, studded with potentially damaging DNA sequences over which hundreds of thousands of sentries stand guard. These sentries, called epigenetic marks, attach to the double helix at such spots and prevent the underlying DNA...
Focus on quiescent cells brings to light the essential role of RNA interference in transcription control
November 9, 2016
Cancer forms when quiescent cells begin dividing and proliferating. New research from the Martienssen lab demonstrates that the RNAi machinery—which is often mutated in cancers—plays a key role in this transition, holding cells in quiescence.
5th Graders spend a day as young scientists
December 16, 2015
LabDish blog …and it was “the best trip ever.” A tiny amoeba crawling across a microscope slide is much more likely to grab kids’ attention than a lecture on single-celled organisms. Any science teacher knows that a hands-on demonstration like setting up a microscope or dissecting an earthworm is the most surefire way to engage...
What’s behind million-dollar crop failures in oil palm? Would you believe bad karma?
September 9, 2015
A way to prevent damaged plantlets from being grown, to boost yield and reduce tropical land pressure Cold Spring Harbor, NY — What has spoiled tens upon tens of thousands of fledgling oil palm plants at elite corporate plantations in Malaysia and elsewhere in Southeast Asia over the last three decades? The answer to this...
How a molecular Superman protects the genome from damage
October 16, 2014
The Martienssen lab found that Dicer, a canonical RNAi protein, facilitates the release of transcription machinery from DNA during replication, thereby preventing collisions and protecting the genome from damage.
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 atCSHL Institutional Repository