In “This strange marine creature has an immune system remarkably similar to ours: Golden star tunicate could help scientists uncover new approaches for preventing organ rejection, treating cancer” (Science, 5Dec2018, doi: 10.1126/science.aaw2860), Mitch Leslie writes:
“The golden star tunicate may look like a flower, but this marine invertebrate is a brawler, attacking its tunicate neighbors in melees that feature ferocious cell-to-cell combat. Now, scientists have discovered that the immune system of this pugnacious animal shows some unexpected similarities to our own. The finding could help uncover new approaches for preventing rejection of transplanted organs or treating cancer.
” ‘It’s pretty exciting,’ says comparative immunologist Larry Dishaw of the University of South Florida College of Medicine in St. Petersburg, who wasn’t connected to the research. ”They’ve laid out a nice, convincing story here.’
“Tunicates are the closest living relatives of vertebrates—the group that includes humans, sharks, mice, and turtles—but the two evolutionary lines separated about 500 million years ago. The 3-millimeter-long, tube-shaped animals cluster in colonies on rocks and other hard underwater surfaces, fanning out like petals. When one growing colony contacts another, they have to decide ‘are they going to fight or are they going to fuse,’ says study co-author Benyamin Rosental, a cellular immunologist now at Ben-Gurion University of the Negev in Beersheba, Israel.
“To probe how the golden star tunicate’s immune system works, a team led by Rosental and bioinformatician Mark Kowarsky of Stanford University in Palo Alto, California, isolated 34 types of cells from the animal. They found some cells switched on the same genes that are active in our hematopoietic stem cells, the blood-forming cells that spawn all the cells of our immune system. Like vertebrate hematopoietic stem cells, the tunicate versions can divide and specialize into different cell types, the scientists determined.
“The researchers identified other parallels between the tunicate and vertebrate immune systems. Cells such as macrophages that devour invaders are a key part of vertebrate defenses. The animals harbored three kinds of these protectors. One type had never been detected before in the tunicates, and it shared a similar gene activity pattern with macrophages.”
And that is just an excerpt.
Recommendation for students: read the original article and identify how its structure is similar to other SAT science readings.