The Genetic Oddity that gives Cephalopods their Smarts (All Hail Cthulhu!)

It’s no secret on this blog that I’m fascinated by the intelligence, and recent increase in population size of cephalopods (and by extension their potential to take over our world…).

Octopuses can open jars, squid communicate with their own Morse code and cuttlefish start learning to identify prey when they’re just embryos.

And it turns out that their intellect might be related to the way that they edit their genes. Read about it here.

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The explanation and importance of N50 (or lack there of)

It’s pretty hard to quantify how “good” a genome or transcriptome assembly is. How do you tell you got it right? How complete is it?

One way to determine if it’s a good is N50, which is kind of a confusing concept. It’s not quite the mean, or the median length, but it is well explained in a new post over at the Molecular Ecologist!

And they promise that the importance/misinterpretation of this well used standard for genome/transcriptome assembly will be explained in future posts.

I’m looking forward to the rest of the series!

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Ambitious plans to sequence every organism on earth, seeks funding

“When it comes to genome sequencing, visionaries like to throw around big numbers: There’s the UK Biobank, for example, which promises to decipher the genomes of 500,000 individuals, or Iceland’s effort to study the genomes of its entire human population. Yesterday, at a meeting here organized by the Smithsonian Initiative on Biodiversity Genomics and the Shenzhen, China–based sequencing powerhouse BGI, a small group of researchers upped the ante even more, announcing their intent to, eventually, sequence “all life on Earth.””

Interested? Read more over at Science. 

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Rewriting the book on Lichens

As I mentioned on Friday, science communication is all about stories. And this one is a doozy.

After a not so traditional education, Toby Spribille has found that lichens are not what we thought they were. We have long known that lichens are 1 part algae and 1 part fungi.

But it turns out that’s not true. Turns out, it’s 2 parts fungi (two different types of fungi to boot), and 1 part algae. We’ve been getting it wrong for decades.

Read the story of this discovery over at the Atlantic!

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Notes from the Field: The Maelstrom of Bee Viruses

I recently completed my PhD (yay!) and started my postdoc (eep!). I’m working at Martin-Luther University in Halle-Wittenburg. It’s no secret that I’m obsessed with the genetics of coevolution, I studied it in snails and trematodes in New Zealand for the last 6 years. So this postdoc is a change of pace in a very similar subject.

#pollinatorselfie

#pollinatorselfie

I’m studying the genetics of host-parasite coevolution in bees and their viruses. Specifically, I’m looking at host shifts, the genetics of increased virulence and the effect of recombination and migration on local adaptation. WHO’S EXCITED JUST BY READING THAT LAST SENTENCE? Me.

Honey bees with their varroa mites (the red dots near their wings)

Honey bees with their varroa mites (the red dots near their wings)

Let’s start with a little background. Bees have been declining across Europe and the US for the last few decades and the reason why isn’t quite clear. One hypothesis is that it is due to infestation with varroa mites, tiny mites that feed on the hemolymph of honey bees and increased in prevalence across Europe over the past few decades (similar pattern around the world except for Australia). However, the extent to which the varroa kills/harms/reduces the fitness of honey bees is unclear.

 

Enter the virus (and me, really). There are a series of viruses that are found in bees everywhere, including in honey bees, bumble bees and wild bees, Deformed Wing Virus (DWV). But it’s been at relatively low levels, and doesn’t seem to cause serious mortality within hives. Unless, that is, DWV occurs with varroa mites. Then the virus sweeps through the population, annihilating the hive. So, is this increase in virulence of DWV associated with an ecological shift, such that the varroa mites are injecting the virus when they feed, rather than the bees simply eating the virus when it’s found on flowers? Or is it a genetic change that has caused the virus to sweep through populations where it previously was fairly benign. And does this effect honey bees, or is it spilling over into the bumble bee and wild bee populations?

Honey bees with DWV.

Honey bees with DWV.

Which brings me to the field. The first step of my postdoctoral position has been to collect honey bees and bumble bees from islands off the coast of Scotland. Why islands? Because everything on the mainland is saturated with varroa mites. To compare the effect of the virus on bumble bee populations with and without varroa we’re looking at three types of islands: islands without honey bees (varroa can only infect honey bees), islands with honey bees and that don’t have varroa, and islands with honey bees and varroa. The list of things I want to do with this data is long, and will involve another post (stay tuned), but for starters we’re looking for transcriptional difference between the virus in these three types of islands.

And maybe looking at local adaptation. Or trying to understand how long it takes negative frequency dependent selection to act within an haplodiploid population. Or using spatial covariance to find the genomic regions involved in coevolution. Stay tuned kids, this is going to get exciting.

In the meantime, I’ve got to go collect some more bees.

Where the bees are. In this case, Colonsay Scotland.

Where the bees are. In this case, Colonsay Scotland.

 

Crowd-funding a Joshua tree reference genome

(Flickr: jbyoder)

(Flickr: jbyoder)

Remember Joshua trees? If you read this blog, you probably do. They’re an ecological keystone species — and a cultural icon — in the Mojave desert, and they have a fascinating, co-evolving relationship with yucca moths. Some contributors to this very blog, have been studying that pollination relationship and its evolutionary consequences for a decade, building on natural history research that goes back to the time of Charles Darwin.

Up to now, though, modern genetic tools have been of limited use for Joshua trees, because no one has assembled the complete DNA sequence of a Joshua tree. Having a “reference genome” would let those of us who study the trees identify specific genes involved in coevolution with yucca moths, compare the evolutionary effects of that pollination mutualism to natural selection exerted by the harsh environments in which the trees grow, and even use genome-scale data to inform Joshua tree conservation planning.

Well, we’ve decided it’s time to do all of that, and we’re asking for help. A team of folks with expertise in Joshua trees’ natural history, Mojave Desert ecology, and genomic data analysis launched the Joshua Tree Genome Project a couple weeks ago, with a crowd-funding campaign on Experiment.com to pay for part of the DNA sequencing we’d need to assemble a reference genome.

We’re approaching 50% of our funding goal, and leading a competition among projects based at undergraduate universities to recruit the most donors, which could win us $2,000 in matching funds — so even if you give as little as $1, you’re providing a big boost to the project. Go check out the Joshua Tree Genome Project website, and then head on over and pledge your support.