Anthony De Tomaso: Finding the origins of adaptive immunity

The adaptive immune system in vertebrates seems to have come out of nowhere; B and T cells and mechanisms used to recognize and remember specific pathogens are missing in species that are only a step below vertebrates on the evolutionary ladder. Anthony De Tomaso is trying to figure out this puzzle, immunol-ogy's version of the big bang, using what he calls " the swing species between vertebrates and invertebrates " —the sea squirt. This model, also known as Botryllus schlosseri, is a translucent bag of biological tricks that De Tomaso wants to understand. Botryllus starts off looking like a tadpole, but matures into an adult that grows via asexual budding into a genetically homogenous colony. Adult stem cells within each separate bud then regenerate that bud on a weekly basis. Contact between two genetically similar colonies of buds causes the two to fuse into a chimeric colony in which stem cells from each animal compete to take over the germline of the other. Dissimilar colonies, by contrast, remain separate, owing to an inflammatory reaction that resembles the rejection of a transplanted organ. As a postdoc, De Tomaso helped identify the gene that controls the choice between fusion and rejection, which came to be known as the fusion histo-compatibility (FuHC) gene (1, 2). The same gene also seemed to protect the animal against parasitic stem cells from another sea squirt (3). Later, De Tomaso took over for his former mentor as head of the lab. His group then uncovered a potential receptor for FuHC (4). They are now trying to understand how the receptor's signals decide between a fusion or rejection reaction. In a recent interview, De Tomaso explained how his unique research model allows him to indulge his varied scientific interests. How did you get interested in scientifi c research? During the summer of my junior year at Stanford, I took a class in subtidal zoology. But then I wanted to see marine biology in action. So I got an internship at Stanford's Hopkins Marine Station, where the summer classes are very intense; there are 12–14-hour days, with labs, lectures, independent research, etc. I had never been a good book learner, so it wasn't until this research experience that my interests in science solidifi ed. As an undergrad, how did you deal with the intensity of the internship? Well, I had learned diving in high school. And this class had …