Event date:
Feb 24 2021 9:00 am

Understanding the Strategies Evolved by a Very Successful Transposable Element

Speaker(s)
Prof. Dr. Susan Wessler
Venue
Zoom/Online
Abstract
Transposable elements (TEs) achieve high copy numbers through waves of amplification called bursts. For a TE to successfully burst it must be able to significantly increase its copy number without killing its host or being silenced by genome surveillance (epigenetic) mechanisms. However, because the vast majority of TE bursts have been inferred after the fact – via computational analysis of whole genome sequence – the stealth features they require for success have remained largely undiscovered. Some features have recently been discovered by analyzing active bursts of the miniature inverted repeat transposable element (MITE) mPing and its autonomous partner Ping in four strains of domesticated rice (Oryza sativa, temperate japonica). First, mPing targets genic regions but avoids exon sequences, thus minimizing harm to the host. Second, because mPing does not share coding sequences with Ping, increases in its copy number and host recognition of its sequences do not silence Ping genes, thus allowing the continuous production of the proteins necessary to sustain the burst for decades. Additional insights into the mPing burst comes from analyses of an extensive collection of rice genomes including 3000 domesticated strains and a recombinant inbred population. While the survey of 3000 strains revealed that the burst is very recent and is restricted to a few closely related accessions, analysis of the sequences of 272 recombinant inbred lines demonstrated the potential of mPing to rapidly spread unimpeded through a large population and increase the frequency of structural variations.

Join us LIVE with Prof. Dr. Susan Wessler from University of California Riverside. Prof. Wessler talks about how transposons evade host defense in rice and increase their copy number without causing death of their hosts. Transposable elements, also known as jumping genes, are special class of genes that naturally exist in a silent state within genomes of every living organisms. They are a major threat to genome stability of a living organism and literally play a havoc with genome when they start jumping and lead to large scale mutations. Prof. Wessler shares about special class of transposons and how they amplify in rice. She is a highly accomplished plant biologist who is the recipient of several awards including the Stephen Hales Prize (2011) from the American Society of Plant Biologists, the Excellence in Science Award from FASEB (2012) and the McClintock Prize for Plant Genetics and Genome Studies (2015). She is a member of the National Academy of Sciences (1998), the American Academy of Arts and Sciences (2007), the American Philosophical Society (2013), and a Foreign Member of the Royal Society (2017).

 

Biography:

Susan Wessler is Distinguished Professor of Genetics and the Neil and Rochelle Campbell Chair for innovation in Science Education at the University of California Riverside. In 2011 she was elected Home Secretary of the U.S. National Academy of Sciences (NAS), the first women to hold this position in its 150-year history. She is a plant molecular geneticist known for her contributions to the field of transposon biology and plant genome evolution. A native of New York City, she received a Ph.D. in biochemistry from Cornell University (1980) and was a postdoctoral fellow at the Carnegie Institution of Washington (1980-1982). She began her career at the University of Georgia in 1983 where she remained until moving to UC Riverside in 2010. 

Prof. Wessler has contributed extensively to educational and diversity initiatives.  As a Howard Hughes Medical Institute Professor (2006), she adapted her research program for the classroom by developing the Dynamic Genome (DG) Course where incoming freshman can experience the excitement of scientific discovery. The DG course is currently taken by over 500 students / year.  As NAS Home Secretary, she has spearheaded initiatives that have led to a 40% increase in the number of women elected to membership in the NAS.

She is the recipient of several awards including the Stephen Hales Prize (2011) from the American Society of Plant Biologists, the Excellence in Science Award from FASEB (2012) and the McClintock Prize for Plant Genetics and Genome Studies (2015). She is a member of the National Academy of Sciences (1998), the American Academy of Arts and Sciences (2007), the American Philosophical Society (2013), and a Foreign Member of the Royal Society (2017).