Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey,
Speaker 1: brain Stuff, Lauren Volga bomb here. Three billion years ago,
Speaker 1: things on Earth were different. For one thing, there wasn't
Speaker 1: all this oxygen all over the place. The first cyanobacteria
Speaker 1: had to figure out a way to live on volcanic
Speaker 1: carbon dioxide, water, and sunlight alone. These old timey organisms
Speaker 1: lived anaerobically, that is, without oxygen. Strangely enough, what we're
Speaker 1: breathing today is the type of atmosphere that they made
Speaker 1: possible for us. Because the byproduct that they excreted oxygen,
Speaker 1: eventually overtook Earth's atmosphere. Any remaining anaerobic organisms were forced
Speaker 1: into the oxygen less nooks and crannies of the planet
Speaker 1: and kept simple and single celled. However, when there's a rule,
Speaker 1: there's usually an exception, and a group of scientists have
Speaker 1: discovered a small parasitic niderian that is a tip of
Speaker 1: a jellyfish that apparently doesn't use oxygen to breathe. They
Speaker 1: publish their findings in the February issue of the Proceedings
Speaker 1: of the National Academy of Sciences. This animal, taxonomical name
Speaker 1: Hanagaya salmon acola, is a tiny parasite with a long
Speaker 1: tail that feeds on the muscle tissue of salmon and
Speaker 1: other fish. It's a eukaryote, which just means that it's
Speaker 1: a member of a broad group of organisms that includes
Speaker 1: most of the living things that you can see with
Speaker 1: your naked eye animals, plants, fungi, et cetera. The cells
Speaker 1: of eukaryotes contain all sorts of fancy organelles that they
Speaker 1: are more primitive counterparts the prokaryotes don't have. One of
Speaker 1: those organelles is the mitochondrian, a structure that has a
Speaker 1: tiny genome all of its own, separate from the rest
Speaker 1: of the organism, and which eukaryotic cells use to produce
Speaker 1: energy with the help of oxygen. But within the larger
Speaker 1: groups that we call eukaryotes, there are a few single
Speaker 1: celled non animal species that are anaerobic. They don't have mitochondria,
Speaker 1: but rather something that scientists call mitochondrian related organelles. Annagaya
Speaker 1: salmnicola is the first animal to have this feature. It's
Speaker 1: all very strange, so how did they get this way?
Speaker 1: For the article this episode is based on how Stuff Works.
Speaker 1: Spoke with study co author Stephen Atkinson a research professor
Speaker 1: in the Department of Microbiology at Oregon State University. He said,
Speaker 1: the ancestors of Hanna Guia almost certainly had mitochondria. All
Speaker 1: its closest relatives have mitochondria, so the evolution to an
Speaker 1: anaerobic lifestyle and the loss of functional mitochondria appears to
Speaker 1: be a recent adaptation of that species alone, at least
Speaker 1: that we know of so far. In the cells of
Speaker 1: typical animals, the mitochondria use oxygen in a multi step
Speaker 1: process to create chemical energy. The research team found that
Speaker 1: this parasite has just had to adapt to an environment
Speaker 1: with very little available oxygen. Without the need for mitochondria,
Speaker 1: it lost the genetic instructions for at least several parts
Speaker 1: of the processes that use oxygen. So by losing that
Speaker 1: mitochondrial genome, the parasite saves energy by not having to
Speaker 1: copy genes for things that no longer needs. But how
Speaker 1: can it survive without oxygen in the first place, Atkinson said,
Speaker 1: we presume that it must instead absorb molecules related to
Speaker 1: energy production from the host cells, which have already done
Speaker 1: part of the processing. Stealing something from the host is
Speaker 1: fundamental to parasitism. Like many important discoveries. This finding was
Speaker 1: totally unexpected. The researchers were hoping to compare the genomes
Speaker 1: of two small parasites, but each time they tried to
Speaker 1: run that of the Hanagaya salmonicola, something was obviously very weird.
Speaker 1: Looking into it further, they found itsels contained a little
Speaker 1: empty bag where a mitochondria and might once have been.
Speaker 1: Atkinson said, this discovery has expanded our understanding of what
Speaker 1: it means to be an animal by showing that even
Speaker 1: complex life can evolve in a way to succeed in
Speaker 1: environments without oxygen. Knowing that anaerobic animals can exist alerts
Speaker 1: us to the fact that we must be on the
Speaker 1: lookout for this and other species and maybe look in
Speaker 1: anaerobic environments for animals where we never would have looked before.
Speaker 1: Specifically from mixing zoan parasite research. It means we will
Speaker 1: look for unusual or missing mitochondria in other species from
Speaker 1: now on to try and discover the connections between hosts,
Speaker 1: tissue and environment that lead to loss of mitochondrial function
Speaker 1: to take advantage of anaerobic metabolism. The discovery of anaerobic
Speaker 1: mechanisms in these parasites could also open a new avenue
Speaker 1: for treatment, as specific drugs have been used to target
Speaker 1: other anaerobic parasites. Today's episode is based on the article
Speaker 1: can you live without oxygen? This animal can on how
Speaker 1: stuffworks dot Com. Written by Jesslan Shields. Brain Stuff is
Speaker 1: a production of Our Heart Radio in partnership with how
Speaker 1: stuff works dot Com, and it's produced by Tyler Clain.
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