Assistant Professor Marcus Roper's goal is to apply mathematics to make new discoveries about how cells solve physical challenges. Those challenges and the solutions organisms have found for them have left deep imprints on how life has evolved. For instance, how and why did multicellular life arise?
"It's complex, beautiful and so dynamic," said Roper, in describing the dynamic movement of nuclei in the cells of a fungus. Having genetically different nuclei within a single cell benefits a fungus by making it more infectious, Roper said. However, this advantage only works if each part of the fungus contains a mixture of each type of genetically different nuclei. This is where the traffic-like flow comes in. As the cell's tubular filaments containing the nuclei grow, the flow process continuously distributes the different nuclei throughout the fungus cell, keeping them well mixed for maximum advantage.
The research, conducted with a group led by UC Berkeley life scientist Louise Glass and published July 16 in the early online edition of the journal Proceedings of the National Academy of Sciences, focused on the fungus Neurospora crassa. Fungus cells, unlike animal and plant cells, can contain more than one nucleus, and in N. crassa cells, multiple, genetically different nuclei coexist in the same cell space.
Roper has also been studying an organism in a family known as the choanoflagellates - the closest single-celled cousins of multicellular animals. Scientists believe that something remarkable must have happened following the divergence of choanoflagellates from the multicellular animals to create conditions favoring complex multicellular life. Roper's recently published research uses fluid dynamics to shed light on the benefits for the choanoflagellate Salpingocea rosette to form multicellular colonies.