#nasonia

[mikeoillustrations]

Nasonia wasp comparison, University of Rochester

Pen, watercolor

[a-dinosaur-a-day]

What do you do with Nasonia? What's a cool Nasonia-fact?

I look to see how their dorsal-ventral patterning in early development differs from other insects 

Cool Nasonia fact: They lay their eggs on blowfly pupae and as the Nasonia larvae develop, they eat the blowfly pupae by liquefying them within the casing.

They do a service for all of humanity and are very cute.  

[sickpapes]

Yen, J.H., Barr, A.R., 1973. The etiological agent of cytoplasmic incompatibility in Culex pipiens. J. Invertebr. Pathol. 22, 242–250.

Since our last post, two months ago, we here at Sick Papes have been riding the highs and lows of an almost indescribable emotional voyage from which we have only recently emerged, bursting with joy and self-knowledge.

It all began, like most of our emotional experiences, while we were blasting the Chances With Wolves radio show (which, in case you don't know, plays the best music on the planet) at full volume while dissecting crickets under a microscope. All of a sudden, a song by Jonathan Richman called "Fly Into the Mystery" came on. This song, like many others by Jonathan Richman, is about the beauty and longing of summer nights in Boston. And it began to haunt me.

Driven by an unknown urge, I embarked on a literature search of other beautiful things that have happened on Boston summer evenings. This obviously led me to this 1924 pape, where two dudes took a break from their Great Gatsy-era shennanigans to look through a microscope for one GodDamn second an observe a strange bacteria living inside the ovary cells of the mosquitoes living around Boston and Brookline. These bacteria, subsequently named Wolbachia, remained mostly a curiosity for the next 60 years, thought to only exist in a handful of insect species. It wasn't until the 1990s, when dudes figured out how to use molecular methods to identity cryptic bacterial species, that the trippy truth emerged: Wolbachia infect ~1 million species of insects (and other arthropods and nematodes), and are probably the most abundant endosymbiotic bacteria on the planet. And more importantly, their insane evolutionary success is largely because they can directly manipulate the reproductive behavior of their hosts. 

Somes jokes, like the one about re-captioning every single New Yorker cartoon with "Christ, what an asshole!" stay hilarious no matter how many times you hear them. And it's the same for some research topics: as far as I can tell, every pape that has ever dropped about Wolbachia is fucking amazing. It was in the vortex of insanely hot papes about Wolbachia that we have been trapped for the past two months, unable to stop clinking through to other hot references. It's pointless to try to pick the best of the bunch, but this 1972 pape right here is straight up astounding. (OK, Wolbachia weren't totally ignored until the 1990s, but they were definitely a left-field kinda thing.)

The background is that different populations of mosquitoes from around the world often can't successfully mate with each other. This isn't really a mind-blower - it's the early stages of speciation, where the different populations still look like the same species, but their genomes have independently evolved to the point that they can no longer fit together quite right when they mate.

What IS a mind-blower is that, in this case, the reason these different populations can't reproduce is because of the specific strains of Wolbachia that live in the ovaries of the different populations. If you simply feed the mosquitoes antibiotics, all of a sudden they can reproduce with the other populations. In other words, the Wolbachia bacteria is causing the formation of new insect species. This is also the case in Nasonia wasps, where three totally different species instantly become interfertile if you give them antibiotics. 

The bigger, and more insane, picture is that Wolbachia are passed from mother to offspring directly through the egg cell, and so to ensure their continued reproduction, the bacteria basically take control of the host insect's reproduction. These examples of Wolbachia-driven sterility are one result of this evolutionary pressure: Wolbachia prevent any mosquitoes which don't carry the same strain of Wolbachia from mating, thereby promoting the reproduction exclusively of those hosts which harbor the self-same bacteria. And if this wasn't wild enough, Wolbachia can also kill all male embryos (which they don't like because only the female insects transmit Wolbachia), can directly increase the egg-laying of infected insects, and apparently live in specific cells of the insect brain, doing God-knows-what.

We are relieved that we finally escaped this two month-long, late-night pape-reading vision-quest, but DAMN if it wasn't sweet.