MIT biology professor Yukiko Yamashita has spent much of her career exploring how asymmetrical cell divisions occur. This type of cell division allows cells to differentiate into different types of tissue, and also helps germline cells such as eggs and sperm to maintain their viability from generation to generation. Credit: M. Scott Brauer
The MIT biologist Yukiko Yamashitas research has shed light on the immortality of germline cells and the function of junk DNA.
When cells divide, they usually generate two identical daughter cells. However, there are some important exceptions to this rule: When stem cells divide, they often produce one differentiated cell along with another stem cell, to maintain the pool of stem cells.
Yukiko Yamashita has spent much of her career exploring how these asymmetrical cell divisions occur. These processes are critically important not only for cells to develop into different types of tissue, but also for germline cells such as eggs and sperm to maintain their viability from generation to generation.
We came from our parents germ cells, who used to be also single cells who came from the germ cells of their parents, who used to be single cells that came from their parents, and so on. That means our existence can be tracked through the history of multicellular life, Yamashita says. How germ cells manage to not go extinct, while our somatic cells cannot last that long, is a fascinating question.
Yamashita, who began her faculty career at the University of Michigan, joined MIT and the Whitehead Institute in 2020, as the inaugural holder of the Susan Lindquist Chair for Women in Science and a professor in the Department of Biology. She was drawn to MIT, she says, by the eagerness to explore new ideas that she found among other scientists.
When I visited MIT, I really enjoyed talking to people here, she says. They are very curious, and they are very open to unconventional ideas. I realized I would have a lot of fun if I came here.
By studying fruit flies, Yukiko Yamashita has discovered the function of DNA segments that were previously thought to be junk. Credit: MIT
Before she even knew what a scientist was, Yamashita knew that she wanted to be one.
My father was an admirer of Albert Einstein, so because of that, I grew up thinking that the pursuit of the truth is the best thing you could do with your life, she recalls. At the age of 2 or 3, I didnt know there was such a thing as a professor, or such a thing as a scientist, but I thought doing science was probably the coolest thing I could do.
Yamashita majored in biology at Kyoto University and then stayed to pursue her PhD, studying how cells make exact copies of themselves when they divide. As a postdoc at Stanford University, she became interested in the exceptions to that carefully orchestrated process, and began to study how cells undergo divisions that produce daughter cells that are not identical. This kind of asymmetric division is critical for multicellular organisms, which begin life as a single cell that eventually differentiates into many types of tissue.
Those studies led to a discovery that helped to overturn previous theories about the role of so-called junk DNA. These sequences, which make up most of the genome, were thought to be essentially useless because they dont code for any proteins. To Yamashita, it seemed paradoxical that cells would carry so much DNA that wasnt serving any purpose.
I couldnt really believe that huge amount of our DNA is junk, because every time a cell divides, it still has the burden of replicating that junk, she says. So, my lab started studying the function of that junk, and then we realized it is a really important part of the chromosome.
When I visited MIT, I really enjoyed talking to people here, Yamashita says. They are very curious, and they are very open to unconventional ideas. I realized I would have a lot of fun if I came here. Credit: M. Scott Brauer
In human cells, the genome is stored on 23 pairs of chromosomes. Keeping all of those chromosomes together is critical to cells ability to copy genes when they are needed. Over several years, Yamashita and her colleagues at the University of Michigan, and then at MIT, discovered that stretches of junk DNA act like bar codes, labeling each chromosome and helping them bind to proteins that bundle chromosomes together within the cell nucleus.
Without those barcodes, chromosomes scatter and start to leak out of the cells nucleus. Another intriguing observation regarding these stretches of junk DNA was that they have much greater variability between different species than protein-coding regions of DNA. By crossing two different species of fruit flies, Yamashita showed that in cells of the hybrid offspring flies, chromosomes leak out just as they would if they lost their barcodes, suggesting that the codes are specific to each species.
We think that might be one of the big reasons why different species become incompatible, because they dont have the right information to bundle all of their chromosomes together into one place, Yamashita says.
Yamashitas interest in stem cells also led her to study how germline cells (the cells that give rise to eggs and sperm cells) maintain their viability so much longer than regular body cells across generations. In typical animal cells, one factor that contributes to age-related decline is loss of genetic sequences that encode genes that cells use continuously, such as genes for ribosomal RNAs.
A typical human cell may have hundreds of copies of these critical genes, but as cells age, they lose some of them. For germline cells, this can be detrimental because if the numbers get too low, the cells can no longer form viable daughter cells.
Yamashita and her colleagues found that germline cells overcome this by tearing sections of DNA out of one daughter cell during cell division and transferring them to the other daughter cell. That way, one daughter cell has the full complement of those genes restored, while the other cell is sacrificed.
That wasteful strategy would likely be too extravagant to work for all cells in the body, but for the small population of germline cells, the tradeoff is worthwhile, Yamashita says.
If skin cells did that kind of thing, where every time you make one cell, you are essentially trashing the other one, you couldnt afford it. You would be wasting too many resources, she says. Germ cells are not critical for viability of an organism. You have the luxury to put many resources into them but then let only half of the cells recover.
Read more here:
Unraveling Stem Cells' Secrets: Immortality of Germline Cells and the Function of Junk DNA - SciTechDaily
- New drug candidate uses novel absorption method to target cancer cells in mice - Michigan Medicine - August 22nd, 2022
- Jianping Fu Mechanical Engineering - University of Michigan - July 11th, 2022
- Cell Culture Market Key Drives Zeroing In On The Main Merchants | Danaher Corporation, Thermo Fisher Scientific Designer Women - Designer Women - July 11th, 2022
- Erasing The Stigma Of Sickle Cell Disease Through Advocacy - Essence - June 22nd, 2022
- This One Group Of People Holds The Key To Staying Young, Study Says Eat This Not That - Eat This, Not That - May 2nd, 2022
- Primary Cells Market 2022 is set to experience a significant growth rate | PromoCell GmbH, HemaCare Corporation, Thermo Fisher Scientific ... - May 2nd, 2022
- 3D Cell Culture Market to 2030 | Industry Statistics, Emerging Demands, Forecast to 2030 | 3D Biotek, LLC Advanced Biomatrix, Inc. Becton, Dickinson... - May 2nd, 2022
- Oral Cavity | histology - University of Michigan - April 19th, 2022
- Scientists De-Aged a Woman's Skin Cells by 30 Years - The Daily Beast - April 19th, 2022
- Longboat residents recall the greatest gifts - YourObserver.com - December 24th, 2021
- Nebraska Athletics News: Recruiting Season, Living Robots and Stuck in IKEA - Corn Nation - December 10th, 2021
- Duke Faculty Promoted or Appointed to the Rank of Full Professor - Duke Today - November 8th, 2021
- Lab-Growing Everything Might Be The Only Way To Attain A Sustainable World - Intelligent Living - November 8th, 2021
- Male Infertility Could Be Treated With Monkey Cells; New Study Shows How These Animals Could Help Address the Condition - Science Times - October 28th, 2021
- Insights & Outcomes: Place cells, planarians, and 'prewet' proteins - Yale News - October 28th, 2021
- Using a mini heart model to develop new therapies - MSUToday - October 5th, 2021
- Rowan University hosts National Science Foundation research program for undergrads - Rowan Today - August 31st, 2021
- Loss of a top autism gene may alter neuron structure - Spectrum - January 17th, 2021
- Rogel team receives $11.2M to leverage the microbiome against GVHD - Newswise - October 28th, 2020
- Latest Update 2020: What Are the Key Players Evolving In the Growth of the 3D Cell Culture Market? - re:Jerusalem - October 28th, 2020
- Listings - CON, THE on ABC | TheFutonCritic.com - The Futon Critic - October 15th, 2020
- ABC News Debuts New Primetime Series THE CON Narrated by Whoopi Goldberg - Broadway World - October 8th, 2020
- HOME GROWN: Pumpkins best left on the vine for as long as possible - The Oakland Press - October 8th, 2020
- Official Missteps in Michigan's Worst Covid Prison Outbreak - The Intercept - September 29th, 2020
- Regenerative medicine and war: The next breakthrough in treating injured veterans? - Genetic Literacy Project - September 29th, 2020
- Hematopoietic Stem Cells (HSCs) Market Primary Research, Secondary Research, Product Research, Trends And Forecast By 2026- Kite Pharma Inc., Thermo... - September 29th, 2020
- New research connects the hormones we're born with to lifetime risk for immunological diseases - MSUToday - September 20th, 2020
- School of Science grows by 10 - MIT News - September 10th, 2020
- COVID-19 Drug Discovery and Development Why Diverse Strategies Are Critical - Technology Networks - September 10th, 2020
- Researchers identify environmental components that affect gene expression in cardiovascular disease - The South End - June 21st, 2020
- Hesperos Human-on-a-Chip used to model Alzheimer's and MCI - SelectScience - June 2nd, 2020
- Are immune-compromised kids at greater risk from Covid-19? - Health24 - May 3rd, 2020
- Erika Hersch-Green Wins CAREER Award for Biodiversity Research - Michigan Tech News - May 2nd, 2020
- Science Becomes A Dividing Issue In Year Of Election And Pandemic - Michigan Radio - May 2nd, 2020
- In a CRISPR first, Editas therapy used to fix genes in the body - BioPharma Dive - March 11th, 2020
- Stopping Smoking Allows Healthy Lung Cells to Proliferate - Medscape - February 8th, 2020
- After a bone injury, shape-shifting cells rush to the rescue - University of Michigan News - January 29th, 2020
- Engineer the future of human health with a PhD in biomedical engineering - Study International News - January 29th, 2020
- The Unexpected Diversity of Pain - Scientific American - January 24th, 2020
- BREAKING: A woman gives birth to the Son of God (Part II) - INQUIRER.net - January 5th, 2020
- Collaborative Robots: Rai... - Robotics Online - December 19th, 2019
- VetStem Biopharma Shares the Success Story of Jesse Who was Treated with VetStem Cell Therapy - PR Web - December 8th, 2019
- Stem Cell Therapy Michigan | Regenerative Medicine 248-216 ... - February 27th, 2019
- Stem Cell Treatments Bloomfield Hills, MI | 248-216-1008 - January 9th, 2019
- Michigan Integrative Health Dr. Roy Picard, D.C. - December 27th, 2018
- Breast Cancer Stem Cells Stopping Them In Their Tracks ... - November 23rd, 2018
- Stem Cell Treatments MI | Michigan Center for Renerative ... - November 2nd, 2018
- Michigan Stem Cell Therapy - Foot HealthCare Associates - November 2nd, 2018
- Cancer Stem Cell Research | University of Michigan Rogel ... - November 2nd, 2018
- University of Michigan Stem Cell Research | Treatment and ... - November 2nd, 2018
- Detroit Michigan Stem Cell Therapy - americanregen.com - September 28th, 2018
- Combination of traditional chemotherapy, new drug kills ... - September 4th, 2018
- Stem Cells FAQ Michigan Stem Cell Institute - August 29th, 2018
- Anti-Aging, Regeneration and Stem Cell Supplements - August 7th, 2018
- Families raise money for research into rare diseases - KARE - September 8th, 2017
- Cells that stand in the way of HIV cure: Discovery expands understanding of marrow's role - Medical Xpress - August 5th, 2017
- Turmeric and black pepper fight cancer stem cells - November 26th, 2016
- Michigan company mines stem cells in search of Fountain of ... - November 18th, 2016
- stem cell research | Michigan Radio - October 6th, 2016
- Stem Cell Therapy Treatment at Allure Medical Spa in Michigan - October 6th, 2016
- University of Michigan Stem Cell Research | Experts List - September 20th, 2016
- Five years after Michigan vote on human embryonic stem ... - August 26th, 2016
- Scientists coax stem cells to form 3-D mini lungs ... - August 11th, 2016
- Cancer stem cells - University of Michigan Comprehensive ... - July 25th, 2016
- Michigan Catholic Conference: Home - October 19th, 2015
- Michigan Stem Cell Amendment, Proposal 2 (2008 ... - July 2nd, 2015
- University of Michigan Stem Cell Research | Embryo Donation - May 12th, 2015
- University of Michigan Stem Cell Research | Stem Cell ... - April 22nd, 2015
- How to grow a human lung - March 25th, 2015
- Novogen (NVGN) Promising Data in Brain Cancer; eFuture Information Technology (EFUT) and ... - March 5th, 2015
- Stem Cell Research - Right to Life of Michigan - February 24th, 2015
- Breast Cancer Stem Cell Research - University of Michigan ... - January 17th, 2015
- What makes pancreatic cancer so aggressive? New study sheds light - January 16th, 2015
- Leukemia Stem Cell Research | University of Michigan ... - January 4th, 2015
- Seeing Is Believing - December 12th, 2014
- Swiston receives Commitment to Education Award - November 29th, 2014
- Bone marrow registration drive to be held at Saint Mary's College - November 18th, 2014
- Researchers devise a means for growing near 2-D chemical gardens (w/ Video) - November 11th, 2014
- Stem cells help doctors restore womans smile, regenerating bone to hold dental implants - November 5th, 2014
- Reason to Bree-Lieve: Greenville girl continues to beat the odds - November 5th, 2014