Helen FieldsScience Writer

For ScienceNOW this week I wrote about a giant virus that lives in the ocean. Viruses are generally thought of as teeny little things that can’t do much for themselves, but this one has 730,000 base pairs of DNA – more than some bacteria – and has genes that encode for a lot of the machinery of protein-making. That is wacky. It’s bigger than some bacteria, too. That’s significant because bacteria are alive, but viruses aren’t. The newly described virus is called Cafeteria roenbergensis virus because it infects a single-celled organism called Cafeteria roenbergensis. Here’s my very short story.

Viruses are pretty neat. Look at this picture. The big round gray thing is one individual Cafeteria roenbergensis. (The host.) See all the little hexagons inside? Those are the virus.

photo by M.G. Fischer

So, it turns out, “Thoroughbred” isn’t just something you say about horses that have a known lineage; it’s a particular breed. There are tons of horse breeds, like Clydesdale and Barb and Arabian and Kentucky Mountain Saddle Horse. Thoroughbreds are bred for speed, but they also have ideas – which is useful when they’re your partner in chasing foxes or running the Kentucky Derby, but annoying at other times.

These are some of the useful facts I might have learned at age eight, if I’d gone through that horsey phase. But I caught up on them last week while working on this story for ScienceNOW about Thoroughbreds’ ancestry.

Thoroughbred ancestry on the male side is recorded right back to the start of the breed, around 1700. But, in the beginning, nobody thought the females mattered, so they didn’t keep records. It was kind of generally known that the founding females were native Irish and English horses, but in the early 20th century some horsey people got all worked up about how their founding mothers must have been Arabians like their founding fathers. This study settles the question. (Probably. For now.)

photo: someone on Wikipedia

A new genetic study finds that Alaskan sled dogs, the mutts that pull sleds, are actually their own breed. Despite coming in all sizes, coat lengths, and ear shapes. The people who breed Alaskan sled dogs feel free to mix in any other dogs they want. They aren’t making purebreds, like a poodle breeder would. But still, the genetic signature – the doggy essence – that all those all those dogs share is Alaskan sled dog. (Not, as the researchers expected, Siberian husky or Alaskan malamute.) Read all about it in my ScienceNOW story.

Photo: Heather Huson

Some scientists at the University of Georgia are working on what sounds like a kind of goofy project: making ornamental clovers. They swear they’re very pretty plants – lush green, with red and white markings. And they fix nitrogen, so they could help fertilize your garden, too. The Georgia team has actually bred three ornamental varieties, called Patchwork Quilt, Irish Mist, and Pistachio Ice Cream, which they’ve turned over to the university to commercialize. So keep an eye out for these to plant in your garden.

In the course of all this breeding, the team has been working on mapping genes for different traits – including the four-leaf trait. This turned out to be really tricky. So, there’s a gene for four leaves. But just because a plant has a gene doesn’t mean it’s always turned on. (You have a ton of genes for making digestive enzymes. The cells that line your small intestines turn these genes on, but you should be pretty grateful that the cells that line your eyeball don’t.) The four-leaf trait comes and goes depending on the season, for example. It’s also recessive. If you want to map it, you need a grad student who’s willing to spend a few years crawling around on her hands and knees counting leaves.

I wrote about that grad student, and the four-leaf gene, for the July 9 issue of Science magazine – but you have to have a subscription to read my story. (Or if you e-mail me and ask nicely, I’ll send it to you.)

Photo: came with the press release. I can’t find a credit for it.

For this week’s issue of the Chronicle of Higher Education, I wrote a story about a molecular link between stress and death. The story is here. Ok, there’s a catch: You have to be a subscriber to read it, and I’m not 100% positive it’s worth $40. (It might be – the Chronicle’s got good stories.)

People have known for a long time that stress is bad for you. Having good social support isn’t just, you know, the reason to live, it’s also good for your health. The guy who did this study worked out a link in the biological chain between stress and death.

The molecule he was looking at is called a transcription factor. A transcription factor is a little protein that grabs onto a strand of DNA near a gene and says, “Hey, transcribe this gene!” In this case, the transcription factor is activated by a stress hormone and turns on a gene that makes a protein involved in inflammation, part of the immune response. Inflammation is fantastic for, like, healing cuts, but we modern humans tend to turn it on and leave it on, which leads to heart disease and other nasty stuff.

So that’s what the story’s about. This was my first time writing for the Chronicle – my editor there is a former colleague from U.S. News & World Report, and it was fun to be reunited for this story.

At the very least, you should look at the great portrait they took of the scientist. He works at UCLA, but he happened to be on campus at Stanford (my first grad school alma mater) the week they needed to take a picture of him, so this is a picture of him with one of the many Rodins that litter campus. Anyone recognize the sculpture? It’s reasonably famous.

Last weekend I wrote a blog post for ScienceNOW about whether “test tube” babies are healthy. Answer: Basically, yes, but the oldest one is only 31, so there’s no way to know about health effects that show up later in life. And there are definitely differences between babies conceived in vitro and babies conceived the natural way. The differences are epigenetic, which means they’re not differences in the genes themselves – they’re related to how the genes get expressed.

This is related to a shift in how people think about biology. For decades after DNA was discovered, everyone was really worked up about the genetic code, and how genes are a blueprint for everything. But the truth is, of course, much more complicated. Just because you have a gene doesn’t mean that it’s being expressed. It might be turned off entirely, or only weakly expressed, or only expressed in some cells and not others. Epigenetics is about looking at differences in how genes are expressed (turned into proteins).

You can understand the blog post even if that doesn’t make sense

Fun fact: They aren’t test tube babies, they’re actually petri dish babies.

Another fun fact: The picture with my story is of an egg being fertilized by intracytoplasmic sperm injection (ICSI) (“icksee”). While in vitro fertilization was developed to get around female infertility, ICSI is for male infertility. As long as the guy is still making some sperm, you can fish them out and inject one right into the egg.

For today’s Welt I wrote about colorblind monkeys – scientists cured them of their colorblindness with gene therapy. “Cured” is kind of a silly word in this case. The males of this species naturally don’t see red and green, so it’s not like they have something wrong with them that needs to be fixed. So, more accurately: Scientists gave monkeys a gene for a pigment they didn’t have, and now the little guys see colors like we do.

Aww, lookit the cute li’l monkey doing the test! He’s supposed to find the pink dots among the gray dots. If he gets it right he gets a drop of grape juice.

The monkeys in the study are squirrel monkeys. Isn’t that a cute name? It sounds tiny and adorable, and like it would enjoy hopping around in trees, which I think is a fairly accurate description of the species. So, guess what the German word for them is? Totenkopfaffen. Death’s-head monkey. Yipe.

Progress update: I actually wrote this story in German, rather than writing in English and translating. And it ran in TWO newspapers today. Woo. I’ve mostly written for Die Welt so far, but the science section also supplies stories for Welt am Sonntag (the Sunday edition)  and Berliner Morgenpost. 

Photo Credit: Neitz Laboratory

For today’s paper, I wrote about late blight – you may know it better as potato blight, the disease that caused the Irish Potato Famine. It’s still a huge problem for potato and tomato farmers, so a bunch of scientists sequenced its genome (their paper is in Nature today). Here’s my story.

Usually when I read about some new genome sequence, I get a big “eh” feeling. As in, “eh, big string of As, Gs, Cs, and Ts, who cares.” But this is a really cool disease, and super important economically, and it turns out the genome itself is interesting, too.

The organism that causes late blight has a ginormous genome, with a ton of repeating sequences of DNA. Those big repeaty areas include lots of copies of the nasty genes that help it attack plants, like genes that cause cell death and stuff. So maybe there’s some way that the bug is using those extra copies to overcome the plants’ defenses. Cool, huh?

Chad Nussbaum, the guy at the Broad Institute whose group did the sequencing, said this genome was really hard because of all the repeats – and it helped them figure out stuff they can use later. “Every genome teaches you something new,” he told me. “They’re all strange in their own little ways.”

Best thing I found while working on this story: PotatoPro, a news source for the potato processing industry with headlines like “Sultry Sally has re-launched its low fat potato chip with even less fat” and “Man dies after falling into potato harvester.”

Part of the deal with this fellowship is that I’m also supposed to do my regular work. So, here it is: a news story about rice genetics. I know, it sounds boring, but it’s totally not! Modifying rice is a big deal – in 2005, 20 percent of the world’s calories came from rice, and production is going to have to increase to keep up with population growth. So this piece is about one cool new study on finding a gene that helps rice survive floods.

An interesting point about this work is how old-school it is. They’re looking for genes, but not using super-newfangled proteomics or whatever techniques – instead, they look for them by doing lots of mating plants together and looking for crossovers, like I learned about in intro biology in approximately 1994. Ok, yeah, computers do all the calculations now. But if they were teaching it in intro biology in 1994, believe me, it was basic.

Then when they find the gene, they don’t put it into another plant with viruses or fancy-schmancy genetic transformations – they do it with breeding. Sure, they use molecular techniques to make sure they’re getting the right genes in the offspring (this speeds things wayyyy up). But basically it’s good, old-fashioned plant sex.

Neat, huh? Made me want to learn more about the world of rice research.