Try to imagine the following situation: a cheetah in the savannah is chasing a prey and it finally catches it after a while. Exciting, right? (well, at least for the cat). The cheetah exercised so hard, ran so fast to catch that elusive antelope that it now needs to rest and catch its breath again, right? Now, let’s picture the same situation, except the prey is a fish and the predator a seal. There is one big difference: the seal is not breathing while chasing and catching its prey, but it is doing so at depth and needs to come back to the surface to take a new breath of fresh, precious air…
Can you imagine exercising very intensely, running for example, without being able to breath? How is that even possible, if when you run you actually breath more and faster? You need that oxygen to circulate and reach every possible corner of those muscles? How are seals, then, and other air-breathing marine predators, capable of doing just the opposite?
Weddell seals in a sunny Antarctic day (Mount Erebus in the background)
That is the general framework to understand what this project is trying to investigate. The seals and other marine predators that breath air (whales and dolphins, sea turtle, sea birds, among others) have a series of mechanisms to cope with this particular situation. There are several adaptations that allow these predators to be very successful at that, but there is one in particular that is of relevance for this project: Seals shut down the circulation to everything that is not needed while diving, and these tissues and organs can then go through periods of time with very low (hypoxia) or no oxygen supply (anoxia), and still be functional again when the oxygen comes back. The goal, is then, to document what genes control this mechanism, and once they are identified compared with humans to see if we could potentially have something similar. This, of course, could have very clear medical implications, as it could potentially help treat conditions under which our organs or tissues are exposed to low oxygen (e.g. pneumonia, heart attack, etc.).
Waiting for the right moment to get our sample
How are these people ever going do that? Well, it turns out that the answer is: by collecting samples from live animals so that they can grow cells in the lab and later on investigate these mechanisms. In particular, we are looking at growing cells from the arteries of these animals and, as it turns out, there is an easy way to collect arteries without even touching the animals: collect their placentas after birth. Gross, yes, but it is for science! The placentas are rich in blood vessels and expelled after the birth, so we can get our hands in fresh placentas with live cells, collect the samples and all without even disturbing the new moms and their baby seals. The one thing: This is Antarctica, and things freeze pretty fast, so we are keeping ourselves busy scoping the colonies where Weddell seals are giving birth these days, and once we find a fresh placenta that is not frozen, we sneakily take it making sure the mom and her pup are not bothered by this, and then take samples. Fascinating, and fun, but it is not very common to find fresh samples, so in the meantime, we can take advantage and make fun of the seals that cannot get out of the water 😉