YouTube: https://youtube.com/watch?v=dAYvd52pInY
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Duration:23:09
Uploaded:2019-12-23
Last sync:2019-12-23 14:00
This week's journey comes to you unedited and in real-time as we explore a mysterious infection.

Timestamps:
1:13 - Into The Goop
3:53 - Is The Goop Stopping?
4:14 - The Goop Is Stopping
6:57 - A Sphere Appears
8:20 - Infection
12:03 - Secrets Revealed
15:17 - Expansion
21:00 - Pressure Mounts

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Music by Andrew Huang:
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Journey to the Microcosmos is a Complexly production.
Find out more at https://www.complexly.com

SOURCES:
https://www.ncbi.nlm.nih.gov/books/NBK2042/
https://www.apsnet.org/edcenter/disandpath/oomycete/introduction/Pages/IntroOomycetes.aspx
We recorded something very weird.

Something amazing. Something that absolutely blew our minds.

And so we’re making a video that is different for us. And the fact that it happens over the course of 20 minutes is absolutely astonishing, it is a very brief amount of time. But it also means that we have made the possibly incorrect decision of sharing it with you unedited and in real time.

It’s just so cool that we couldn’t bring ourselves to edit it. We didn’t want to speed it up. We wanted it to take its course over the amount of time that it took in the real world.

But of course, we also don’t have enough to say to fill up 20 minutes of video...so the narration will be coming in and out as the...event...progresses. If you don’t have a full 20 minutes to watch it, we have put the time codes of those narrations in the description. You can click on them and go to the moment in the video where I will be talking about what’s happening.

So, to begin... Daphnia are a type of crustacean. They’re known for the way they seem to jump while they swim.

And one day, about a year ago—coming from a cold pond in winter—a daphnia laid an egg that eventually made its way under our microscope, that large, dark oval you see there taking up the upper left corner of the screen, that is the Daphnia egg. But we’re not really going to talk about Daphnia today because, as previously mentioned...things got weird. At the bottom corner there, you can see that the egg is...leaking?

If you know nothing about the reproductive habits of water fleas, and it’s totally understandable if you don’t, there’s a sense of order to that movement that might make it seem innocuous, a slow movement from one oval to another as the leaking substance becomes enveloped in a membrane. It looks, at least, intentional. But James, our master of microscopes, has spent hours every day looking at the samples he collects.

And when he saw this, he knew something very strange was going on—he just didn’t know what. So, he did the obvious thing and hit record. So...watch with us… Ok, is it done?

Did it do the thing? There is something vaguely intestinal about what we’re watching here like the egg is evacuating a part of it- Oh...no...there’s more. It’s still coming.

Ok, this is it. That is the last bit of whatever the goop was. It has transferred itself out of the egg and into this...brown blobby thing.

Ok, over the last few minutes, our misshapen blob took on a more definite, spherical shape. Also, whatever came out of the daphnia egg appears to be well and truly alive. And as James changes focus, we can see that this larger sphere appears to contain not just goop, but smaller spheres bound together by that enclosing membrane.

They’re giggling...they’re moving...they're alive...they are cells. Now this started to seem like something we might understand...this egg, it seems, was infected with something...and that something had succeeded. It was an intruder that--having got what it needed from its host--was moving on to the next phase of its life cycle.

And while the bulk of this image might consist of the Daphnia egg, what we’re actually watching—the leaking, the cell-forming, the swimming—is the reproduction of a parasite. It took months of searching, but we later learned that this parasitic species is some type of oomycete, which, if you know your science Greek, you’ll recognize as a “egg fungus.” Now, it’s actually not a fungi, but it does behave like a fungus in many ways. And oomycetes are responsible for some of the most harmful plant pathogens, including the one responsible for much of the Irish potato famine.

They’re most closely related to algae, but they aren’t really very closely related to anything. And the cells inside the membrane are zoospores, they have flagella and the membrane is called the sporangium. But the oomycete is still not done here, and the strangest part is yet to come.

In its own creeping way, the bundle here looks like it’s expanding, as the zoospores inside swim more freely and energetically, they collide against each other, taking up more and more space like a gas heating up. Eventually, we imagine, they’re gonna take up so much space that the sporangium will rip apart, but not yet. Now, the pack of zoospores is getting bigger—their movements look almost frantic, pushing and pushing against the sporangium.

They are waving their flagella, triggered by some stimulus, bouncing off of each other, straining the membrane. The Sporangium is getting larger and larger, and then one zoospore breaks away….the membrane, though invisible, has now definitely broken, and it peels back and all of its zoospore friends begin to follow...each of them searching for a new host...each with the potential of starting this whole process all over again, to the definite detriment of the next generation of daphnia. That was wild.

Of course we wish we could have captured more of the beginning of this process...but from the completion of the evacuation from the egg to release of the sporangium was less than 20 minutes in real time. It’s hard to be on the side of these little parasites, but that doesn’t mean that they aren’t fascinating! Thank you for coming on this journey with us as we explore the unseen world that surrounds us.

Sometimes, apparently, we’re gonna do it in slightly different ways. We’re gonna let what happens on the other end of the microscope dictate what we do here on this channel, and we hope you are ok with that. If you are, you are welcome to join the community of people who helps us make these videos, including all of the names that are on this screen right now.

Thank you for joining our Patreon. If you want to see more from our Master of Microscopes James, check out Jam and Germs on Instagram. And if you want to see more of what we’re up to, there’s always a subscribe button somewhere nearby.