What would you do with another lifetime?
While doubling the human lifetime may not currently be feasible, it has been done with microscopic worms. The Ellison Medical Foundation has recognized Susan Strome, a professor of molecular, cell and developmental biology at UC Santa Cruz, as a Senior Scholar in Aging for her work in extending the lifetime of the nematode worm, C. elegans.
According to their website, the Ellison Medical Foundation is an organization that “supports basic biomedical research, with a current focus on understanding how humans and other organisms age and on defining the fundamental biological mechanisms that prevent age-related diseases and disabilities.”
The Ellison Medical Foundation will give Strome’s lab an award of $600,000 over the next four years. As one of 27 scientists across the nation who received the Senior Scholar distinction and award, she will have the grant go toward the continuation of her project involving the longevity of microscopic worms.
Strome’s research starts with looking at individual cells of the worms, specifically the germ cells. Present in these germ cells are small particles called P-granules, which are of particular interest to Strome’s research.
“The term germ cell encompasses the cells that proliferate and undergo meiosis and make sperm and eggs,” Strome said. “As a postdoc, I identified some granules that are present in the one-cell embryo, and as the embryo divides into multiple cells, the little granules are sent into the primordial germ cells. The egg contains about 100 granules, then they coalesce into bigger and bigger granules.”
Strome said that she has seen through her research how the P-granules and other mechanisms help germ cells maintain two properties vital to their development.
“One is the ability to divide indefinitely, which we call immortality and two, the ability to give rise to all tissue types, which we call total potency or totipotency,” Strome said. “So I said … ‘these granules are really important for germs’ cells, what happens if these granules end up in somatic cells?’”
Strome said somatic cells are muscle cells, nerve cells, gut cells, skin cells — everything non-germ. Somatic cells do not naturally have P-granules. But early evidence suggests that when somatic cells acquire the P-granules and perhaps other germline traits, it causes the somatic cells to take on some of the immortality that defines germ cells, and live a little longer.
“We’re not making immortal worms. We’re not there,” Strome said. “But there is an extension of lifespan. That’s what my Ellison [Award] is awarded to study.”
The Ellison Medical Foundation promotes research that can lead to improved methods of fighting degenerative diseases that occur due to aging, which is why Strome was awarded the grant for her research.
“[The Ellison Medical Foundation’s] philanthropy extends to model organisms and basic questions that don’t have immediate applications to human health,” Strome said. “It’s not like we’re going to go into humans and start driving germ granules in somatic cells. But the lessons that come through, I think will impact human health in the long term.”
Andrew Knutson, a third-year graduate student, is in charge of the worm life-extension project at Strome Lab. He explained a method that he and Strome use to mutate the worms and their somatic cells with the P-granules.
“The chromosomes come together from mom and dad, and this chromosomal array … is just an extra piece of DNA that can either be transferred into the egg or not transferred, so it’s really random as to how it segregates,” Knutson said. “Some of them have it and some of them don’t.”
Strome said the money awarded from the Ellison Medical foundation will get the job done. She put forth a budget that accounted for two graduate students, one undergraduate technician and supplies. The $600,000 grant is enough to fund this project for the next four years. Strome is currently using her larger National Institutes of Health grant to fund other projects she is working on.
“My big grant is to really try to understand germline and germ-soma distinction,” Strome said. “What keeps germ cells on the correct pathway, what keeps them from deviating to a somatic pathway? We’re really trying to understand the germ-soma decision. The decision has to be made and then it has to be maintained for the life of the animal.”
Geoff Slaughter, a second-year transfer human biology major from Oakes College and assistant at the lab, is also working on the life extension project. He said he has been studying some worm mutations that have not been looked at in a long time, while Knutson is onto newer experiments.
“I’ve been able to do the same kind of experiments but with kind of offshoot things,” Slaughter said. “So there’s a certain set of proteins that this lab has been focused on that Susan discovered way long ago and so I’ve been doing aging studies with mutants of those kind of worms, whereas Andrew is onto newer stuff.”
Regardless of the experiment, Slaughter acknowledged the complexity of the research at Strome Lab.
“The whole idea is to limit the amount of variables … it’s not just like being tall or short, green eyes or blue eyes, there’s all kinds of stuff that’s going on,” Slaughter said. “I’m an undergrad so I get to learn all kinds of fun science-y things that I didn’t know how to do before. [This type of research] is just kind of hot right now.”