Skip to main content

Event Detail (Archived)

RNA-programmed Genome Rearrangement and Editing in the Ciliate Oxytricha

The Joshua Lederberg Distinguished Lectureship in Molecular Genetics

Event Details

Friday Lecture Series
Laura Landweber, Ph.D., professor of biochemistry & molecular biophysics and of biological sciences, Columbia University

The ciliate Oxytricha trifallax possesses a dynamic pair of genomes, and massive DNA rearrangements produce a highly fragmented but functional somatic macronucleus from a complex germline micronucleus. This process eliminates nearly all noncoding DNA, including transposons, and rearranges over 225,000 short DNA segments to produce a second genome containing thousands of gene-sized “nanochromosomes.” In the precursor, germline genome, the shattered segments of different genes often interweave with each other, frequently overlap and sometimes combinatorially assemble. The mature, somatic genome contains over 16,000 nanochromosomes. Noncoding RNAs regulate the entire process of genome rearrangement. Millions of 27nt piRNAs provide the critical information to mark and protect the retained DNA segments of the genome and a distinct set of piRNAs mark a subset of deleted regions to assist with their elimination. Maternally-inherited, long, non-coding (lnc) RNAs provide three additional layers of continuity across generations, including serving as templates for genome remodeling and RNA-guided DNA repair while also regulating gene dosage and chromosome copy number. This illustrates the ability of noncoding RNAs to transmit heritable changes to the next generation. Together, Oxytricha's elaborate epigenome, assembled through complex interacting networks of both long and small non-coding RNAs, encapsulates an RNA-driven world, packaged in a modern cell.

Dr. Landweber received her undergraduate degree in molecular biology from Princeton University and both her M.A. and Ph.D. in biology from Harvard University. She was on the faculty of Princeton from 1994–2016 before moving her lab to Columbia University Medical Center, where she is a professor in the department of systems biology and a professor of biochemistry & molecular biophysics and of biological sciences in the Colleges of Physicians and Surgeons and Arts and Sciences. Dr. Landweber has received a Blavatnik Award for Young Scientists, a Tulip Prize for DNA Computing, and a Guggenheim Fellowship. She was elected to the American Academy of Arts and Sciences in 2005 and is the president of the Society for Molecular Biology and Evolution.

Justin Sloboda
(212) 327-7785
Open to
Luciano Marraffini, Ph.D.
Refreshments, 3:15 p.m. - 3:45 p.m., Abby Lounge
Justin Sloboda
(212) 327-7785

Calendar of Events & Lectures

Browse upcoming and past Events and Lectures by keyword, program, date and type