MCDB Seminar: “Somatic mutations reveal individual histories of development, aging, and inheritance” by Alexej Abyzov (Mayo Clinic)
June 28, 2024
11:00 AM - 12:00 PM
Alexej Abyzov, Ph.D.
Mayo Clinic
https://www.mayo.edu/research/faculty/abyzov-alexej-ph-d/bio-20089449
Host: Yury Polikanov
ABSTRACT:
An adult human body consists of approximately 37 trillion cells—a staggering number, especially considering that everyone develops from a single cell, the zygote. It is now well established that cells accumulate mutations beginning with the first zygotic cleavage. Each cell of a newborn has hundreds of mutations, and this number increases to thousands by old age.
In addition to potentially altering cell function, these mutations serve as developmental and aging fossils recorded in the cells’ DNA. By leveraging these mutations, we discovered up to 90:10 asymmetries in cell lineage contribution to the soma of developing organisms. We further demonstrated that the human brain exhibits a lineage expansion effect similar to that observed in other tissues. Additionally, we found that the human germline is polyclonal and is founded by at least two cells likely descending from the two blastomeres formed during the first zygotic cleavage.
Further analyses revealed that the significant imbalances of up to 90:10 in early lineage allocation in somatic tissues are not reflected in transmission to offspring, establishing a fundamental difference in lineage allocation between the soma and the germline. Finally, analyses of various datasets consistently suggest that the germline
maintains a balanced 50:50 lineage allocation from the first two blastomeres.
Date posted
Jun 24, 2024
Date updated
Jun 24, 2024