Hi. My name is Ina Na, and I'm a PhD student in the Keeling lab.I study apicomplexans, which are a group of parasites that share ancestry with free living photosynthetic algae, and are closely related to the parasites that cause malaria. Apicomplexans can be found in animals all around the world. They can be found even in marine animals, like corals or fish. But they can also be found in animals that are terrestrial,like a variety of insects, you know, your pet dog or even us. Apicomplexans are parasites and sometimes they infect the host cell that make up the tissue itself, and sometimes they'll just attach to the host cell tissue from the outside.

Where apicomplexans are on the tree of life is in an interesting spot because it's closely related and actually shares ancestry with a group that is free-living, photosynthetic algae. Apicomplexans are clearly not photosynthetic and are clearly not free-living with them having more of a parasitic lifestyle. So learning more about the evolution of apicomplexans helps us understand this transition from a free-living, photosynthetic organism to that of a non-photosynthetic parasitic lifestyle. There are a lot of species of apicomplexans that have been described, but not all of them have been put on the tree of life, so we don't know how they relate to other members.

This is a type of apicomplexan that can be found in barnacles. These are actually two cells that are joined together in one of their sexual lifestyle stages. And you can actually see the nucleus here from each of the cells. We use a combination of microscopy and molecular, slash, bioinformatics approaches to study these organisms with the microscopy techniques, we can get a visualization of what they look like on the outside as well as what they look like on the inside with techniques like TEM and with molecular and slash the bioinformatics approach, we can get an idea of their evolutionary history.

Working with these cells, when we're isolating them for TEM, they need to be live, so their structure is together. And then we treat the cells with a series of dilution steps that dehydrates them and then also embeds them into resin. The resin is baked for a bit to make sure that it hardens. And then that hardened resin with the cell inside is sliced through with the slices being put onto a grid where the grid is then put into a microscope, the electron microscope, so that we can visualize it.

Some apicomplexans are pretty well-studied. So you might know about malaria, which is caused by plasmodium, or toxoplasma. However, there's a whole bunch of different apicomplexan lineages that haven't been studied very much. we actually don't know how much they impact their host, We don't know how much their impact is on the environment. And we also aren't quite sure about their biology, on a cellular level. So it really is a really open frontier and it creates a lot of opportunity to explore and form these base lines where we can start to learn more about these organisms.