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grasses

Two classical maize genes, synteny, and the mystery of the missing gene

Colored aleurone1 and Purple plant1 are both genes with long histories in maize research and are involved in the regulation of anthocyanin biosynthesis.The mutant version of purple plant1 does exactly what it sounds like. (In the proper genetic background) it has plants producing anthocyanin (a purple plant pigment) everywhere, resulting in purple plants. The mutant form of colored aleurone1 was identified from a mutant that changed the color of individual corn kernels. Guess which of these two classic maize mutants made it into the top 15 most published on genes in maize, and which fell barely short.

Ears segregating for the colored aleurone mutant phenotype. Image courtesy of MG Neuffer via MaizeGDB.

Purple plant1's phenotype is highly variable depending on the genetic background the mutant is in. Images courtesy of MG Neuffer via MaizeGDB.

The two genes are also duplicates (homeologs) resulting from the maize whole genome duplication. From the picture below you can also see both the two genes and the regions they are in match up to single regions in rice and sorghum, two grasses that haven’t gone though a whole genome duplication since the great radiation of grass species that took place an estimated 50 million years ago (well after dinosaurs stopped walking the earth). (more…)

Oliva Judson’s Salute to Grasses

People who can actually get the general public interested in science are almost as rare as hen’s teeth.* One of those gifted scientist-communicators is Olivia Judson, an english evolutionary biologist who sometimes writes a column for the nytimes and published an interesting/hilarious pop-science book titled: Dr. Tatiana’s Sex Advice to All Creation: The Definitive Guide to the Evolutionary Biology of Sex.**

I mention all this to explain why I was so excited to learn that her post this week sings the praises of a group of species near and dear to my heart, the grasses. The whole post is definitely worth a read. Even if you don’t learn something you didn’t already know, read it as a source of inspiration for telling OTHER people how cool grasses are. And the closing is truly excellent:

We usually talk of our domestication of grasses, and the ways in which we have evolved them: we have made plants with bigger, more nutritious seeds that don’t fall to the ground, for example.But their effect on us has been far more profound. Our domestication of grasses, 10,000 years ago or so, allowed the building of the first cities, and marks the start of civilization as we know it. Grasses thus enabled the flowering of a new kind of evolution, a kind not seen before in the history of life: the evolution of human culture.

Some of the comments are heart warming to read as well, although a bunch of people have fallen prey to the maize/corn confusion. (Explained in detail here)

*Speaking of cool science that most of the general public doesn’t know about: We’ve known for more than four years that mutations of the gene talpid2 in chickens cause chicken embyros to develop teeth, something we thought birds had lost the ability to do 60-80 million years ago (around the same time grass was bursting onto the world stage.) Don’t worry too much about getting bitten by a sabertoothed turkey, the toothed embryos have other problems that mean they don’t survive.

**There’s also a three-part video series based on the book that I can best describe as … odd.

Why to Celebrate the Publication of the Brachypodium Genome

Brachypodium distachyon (photo courtesy of Devin O'Conner)

Sorry this is late going up. -James

This morning Nature officially published the paper* describing the sequence of the Brachypodium distachyon genome. This publication brings the number of grass genomes available for comparative analysis to four. In celebration I’m going to list four reasons to be excited about the publication of this genome.

The location of Brachypodium within the grass family tree.

Brachy (as I will refer to the species from here on) is a member of the Pooideae a sub-family of grasses from which no sequenced grasses have come. For the work we do in my lab this is exciting because it adds more depth to our analysis of changes in the grass genomes. The more distantly related grasses we can compare at the whole genome level, the better we can infer what the ancestral species that gave rise to all the grasses might have been like at a genome level. The most we know, or can make educated guesses about that species, the better position we are in to say what changed along the evolutionary paths leading to grasses like maize, rice, and sorghum. The choice of the Pooideae wasn’t at random, or even because of the sub-family’s distant relationship to other sequenced grasses. (more…)

Why I’m so Excited About the Banana Genome

The single most consumed fruit in America, yet in the tropics this bananas starchy relatives play an even more vital role in feeding whole nations.

At the Plant and Animal Genome Conference next month (which I really wish I was going to), there will be a workshop on banana genomics, but from the abstract submitted by Carine Charron (h/t to Jeremy at the Agricultural Biodiversity Weblog) I learned that:

The sequencing phase will be completed in early 2010 and automatic annotation will take place during the first semester of 2010.

Why is sequencing the banana genome important? Three reasons: (more…)

Figure from my Research Proposal

“My budget…triples the number of National Science Foundation graduate research fellowships.  This program was created as part of the space race five decades ago. In the decades since, it’s remained largely the same size –- even as the numbers of students who seek these fellowships has skyrocketed.  We ought to be supporting these young people who are pursuing scientific careers, not putting obstacles in their path.” – President Obama

I’m still feeling brain dead after the final push for submitting.

Speaking of NSF, here’s the one figure I managed to shoehorn into my research proposal.

Blast hits between an orthologous quartet of gene spaces, one in rice, one in sorghum and the two copies created by the maize tetraploidy.

Blast hits between an orthologous quartet of gene spaces, one in rice, one in sorghum and the two copies created by the maize tetraploidy. As usual click the picture to see it fullsized

If you’d like you can even click here to be able to play around with the figure yourself using the CoGe interface. Now I’ve got to try to explain what this figure is about. (more…)