Off the Press
May 17, 2011
By Laura Geggel
High school science prepares students
I had an excellent biology teacher in high school who taught me all things science.
In her class, I learned about genetics and we even participated in the human genome project, mapping a gene that affected how quickly the body could rid itself of tobacco.
I took science in college, but I’ll always credit my high school teacher for arming me with the fundamentals of biology.
I recently put some of my science prowess to the test. Every month, the Pacific Science Center, in conjunction with KCTS 9 and Science on Tap, organizes three Science Cafés. Each Science Café has researchers present their work while people eat dinner and ask questions following the lecture.
After work May 10, I drove to Kirkland to hear a lecture called “The Modern Legacy of Ancient Viruses,” given by Dr. Harmit Malik, from the Fred Hutchinson Cancer Research Center.
His talk blew me away, and thanks to my high school science education, I understood the fundamentals of his research.
Malik began by telling us about retroviruses, a sneaky family of viruses that can incorporate themselves into our DNA. HIV, for instance, is a retrovirus.
Some retroviruses (but not HIV) can infiltrate and leave their imprints on our reproductive cells, meaning we could pass the virus on to our children.
Malik’s lab, along with other labs, began studying ancient viruses that incorporated themselves into our DNA. Some of these viruses are about 30 million to 35 million years old, and, just like other living things, have mutated over time and are no longer functional.
But, interestingly, in one of them, the viral envelope is in pristine working condition.
Intrigued, scientists studied this viral envelope, called syncytin. They found that it is expressed in the placenta of pregnant women. Further research showed that syncytin allows the placenta to form a layer of cells that get nutrients from the mother’s bloodstream and then carry it back to the fetus.
Scientists also found the viral envelope in sheep and goats, primates, rodents, and rabbits and hares. Each group got the viral envelope from a different retrovirus, and all use it when pregnant.
For an experiment, scientists deleted both copies of the gene in mice. When the mice got pregnant, they had miscarriages because they needed the viral envelope to give nutrients to their fetuses.
So yes, our survival is dependent on a viral envelope from an ancient virus.
Malik then showed us an evolutionary tree. The birds split off early, and of course birds lay eggs, and don’t have the viral envelope. Further down the tree, the platypus split off on its own branch. Platypuses are mammals, but they lay eggs and don’t have the viral envelope.
About 180 million years ago, the common ancestor of primates may have become infected with the retrovirus. In the following millions of years, there was an explosion of mammalian evolution, and the viral envelope played an important role. Every so often, another more efficient viral envelope came along, replacing the old one.
Issaquah School District’s students are learning the fundamentals of biology now so that, like Malik, they can understand, and maybe undertake, tomorrow’s research.
Since students only need two credits of science, the sophomore biology class is the last science course some students take, Skyline High School teacher Joelle Nelson said.
In her class, students learn about DNA and genetics. They even use micropipettes and gel electrophoresis to determine whether a fake patient has the gene that makes breast cancer more likely to develop.
“Getting that big picture of how does life work and how do their bodies work is important not only for their own health, but also for political issues when they go out to vote and understand things like climate change,” Nelson said.