Imagine my surprise when several readers sent me a longish article from the New York Times about the Bloomington Drosophila Stock Center at Indiana University (click on the screenshot below). For, when I worked with flies for over four decades, I used their services—and their fly stocks—constantly. Much of my work would have been impossible without the strains they provided, which involve various kinds of mutations, chromosomal aberrations, genetically engineered strains, and so on. Moreover, as the article notes, Drosophila is the best animal model we have for genetics. It’s been useful not just in pure research, but in applied work. As the NYT notes:
Studying these slight mutants can reveal how those genes function — including in humans, because we share over half of our genes with Drosophila. For instance, researchers discovered what is now called the hippo gene — which helps regulate organ size in both fruit flies and vertebrates — after flies with a defect in it grew up to be unusually large and wrinkly. Further work with the gene has indicated that such defects may contribute to the unchecked cell growth that leads to cancer in people.
Other work with the flies has shed light on diseases from Alzheimer’s to Zika, taught scientists about decision-making and circadian rhythms and helped researchers using them to win six Nobel Prizes. Over a century of tweaking fruit flies and cataloging the results has made Drosophila the most well-characterized animal model we have.
And so I’m glad the Center finally got some recognition, which is well deserved. These people have labored diligently—not just accumulating strains of flies, which now number 77,000 (!), but sending them out to workers throughout the world and—the most labor—making the food that fills the fly vials to keep the strains alive, and changing each stock (kept in replicates to preserve them) every couple of weeks. You can’t freeze Drosophila to preserve them alive like you can bacteria, and so keeping the cultures going requires constant attention. I had hundreds of strains in my own lab, and spent many hours a week just changing exhausted vials into fresh vials. (The article calls this “flipping flies”; we called it “changing flies.)
So my kudos to the center, which kept going—as it had to, if Drosophila genetics were to survive—during the pandemic. The Center’s work during the pandemic is a large part of the NYT story.
Now though there are several thousand of Drosophila species in the wild, only one—Drosophila melanogaster—is kept in Bloomington, for that’s the species that fortuitously was developed by Thomas Hunt Morgan, my academic great grandfather, when he began Drosophila work at the beginning of the 20th century. And that’s the species used as the animal model today. Here are all the various kinds of stocks you can order:
That’s a lot bigger list than existed when I got into the game: we had no genome editing stocks, fluorescent proteins, or binary expression systems. We had mostly chromosomal aberrations, deficiencies and duplications of genes or chromosome segments, and, of course, the classical single-gene mutations. Here are some single-gene mutants (from Wikipedia). “Normal” or “wild-type” flies, as you catch them in the wild, look like the one in the middle at the top, but with brick-red eyes (see second photo below).
A “wild type” fly from the NYT article (photo by Bob Gibbons):
I’ve used all of these mutations at different times, often to see if they were identical to similar-appearing mutations that I found in close relatives that could cross with D. melanogaster and produce offspring. (For example, if I found a “sepia”-like eye color in the sister species D. simulans, I’d cross it to known D. melanogaster sepia; if the offspring all had brown eyes, it was the same mutation. This is known as a “complementation test.”)
Here are a few more photos from the article (captions from the NYT). Some of the 77,000 stocks, kept immaculately:
Changing flies! Every experimental drosophilist spends much of their life doing this:
Here’s a historic stock: white-one, a white-eye mutant discovered by Thomas Hunt Morgan in 1910. Morgan found that when you crossed white-eyed females to “wild type” males, all the male offspring were white and all the female offspring had normal red eyes. In contrast, if you crossed white-eyed males to wild-type females, you found that all the offspring were red-eyed, but the female offspring from that cross produced half white-eyed males and half-red-eyed males. This weird pattern comes because white is a recessive gene on the X chromosome: it’s “sex-linked”—like red-green color blindness or hemophilia in humans.
You can read about Morgan’s study of white here, and see his 1910 paper here. (He won the Nobel Prize in 1933 for his work on classical genetics, but split the money with his “boys”—his extremely talented group of researchers who occupied the “fly room” at Columbia University.)
The white-one stock below has just been put into fresh vials of medium, which is made with water, soy meal, cornmeal, yeast, and a usually a preservative. Within 10-12 days at 25°C, you will get a new generation of adults, as the eggs are laid on the food, the larvae (“maggots”) hatch and burrow into the food (also eating it), and then crawl onto the sides of the vials to spend 4-5 days as pupae (the fly equivalent of a cocoon) before hatching (“eclosing”) into new adults. After about two generations the food is used up and you have to “flip” the vial.
The vial on the right doesn’t seem to have been cleaned very well, as there are old, empty pupal cases still adhering to the walls, which would be washed off during a proper cleaning.
Here are old, grotty, spent vials (the header of the NYT article).
Here’s the original “fly room” at Columbia where the Nobel-Prize-winning work was done. Six or seven researchers crammed into this space, and food (at that time made with bananas) was also prepared here. Only Morgan himself, as the boss, was allowed to eat one of the bananas. You can see a microscope for examining flies in the foreground, and the milk bottles full of fly food on the table:
Here’s Calvin Bridges in the Columbia Fly Room. Bridges, a wickedly handsome man with a colorful and rogue-ish life, was a fantastic researcher and made many contributions to modern genetics:
This book will give you more information about the early history of Drosophila genetics and how it influenced today’s “Drosophila culture”:
Now a lot of my fly work was done with species other than D. melanogaster, though they were close relatives. That’s because I worked on speciation, and to do the genetics of speciation (i.e., finding out which genes and how many of them change during the split of an ancestor into two or more descendant species), you need several species, ideally ones that can be crossed. Since the Bloomington Center contained only D. melanogaster, I got my other species by collecting them myself, getting them from colleagues who collected them, or ordering them from the National Drosophila Species Stock Center, then at Bowling Green State University in Ohio but now at Cornell University.
I see that the NDSSC still keeps some of the mutant cultures I found in the relatives of D. melanogaster, but, sadly, most of them have been lost, since they used to concentrate only on wild-type flies of different species and didn’t want to take the mutations I had laboriously found and identified. But, like the Bloomington Center, they were a huge help to me when I worked on speciation, and I want to thank them as well.
I could go on and on and on about the Centers and their value and their stocks, but I’d best stop here because it’s lunchtime. I’ll just add that I once combined a mutant called groucho (which had extra bristles over its eyes) with proboscipedia (a fly whose mouthparts transform into leglike structures) to get a Groucho Marx fly with bushy eyebrows that looked as if it were smoking a cigar.
Some readers here might be interested in this book published by Harvard Univ Press in 2018:
Stephanie Elizabeth Mohr: First in Fly: Drosophila Research and Biological Discovery
https://www.hup.harvard.edu/catalog.php?isbn=9780674971011
Seems like there’s a missed opportunity for “Lord of the Flies” in this. I worked years ago with Ward’s Natural Science Establishment, who provide everything from rock samples to fetal pigs for dissection. Places like that are fascinating.
When I started my Ph. D. work at IU in 1974, the main stock center (at least for melanogaster) was a Bowling Green. A couple of years later, the Biology Department had the wisdom to hire Thom Kaufman as an assistant professor (he remains active there today), and it was his vision and energy that led to the creation of the Bloomington stock center. The late Kathy Mathews ran the center smoothly and efficiently for years, and many others have contributed as well. I got to visit it a little over a year ago, and I was completely amazed by what it has become. One other note – at the time, they were working on moving backup stocks to a different building, to protect against some disaster occurring in Jordan Hall (location of the center). I’ve been out of fly work for about 20 years, but once a fly guy always a fly guy. Thanks for sharing this.
I remember Kathy Mathews! At least we corresponded a couple times over email when I was doing fly research.
Sub
Is anyone else with gmail having trouble getting the posts?
Google recently has been having system troubles that have affected gmail. My wife’s gmail account wasn’t working for a while yesterday. And then it just started working again.
🤞🤞thanks, Greg
Same here.
Maybe the Ruskies?.
Calls to mind an interesting artifact, the Coli Genetic Stock Center. This was the repository for all of the Escherichia coli K-12 cultures used in basic genetic research. (Maybe you recall learning about E. coli “mating” in a biology class.) It looks like a late 20th century website because E. coli as a basic model organism has kind of fallen out of favor. The collection continues because there still are some uses and because it’s just a couple of minus 80 freezers at Yale.
How nice to see an article about the stock center! I ‘ve wondered what it looked like in there.
There is also FlyBase, which is a web site for all things Drosophila. The data on the genes, mutants, stocks, etc. is mind-blowing.
It worries me to see vials being reused that are not fully clean, b/c of mites. But if they autoclave them then I suppose it could be ok.
Years ago in the midst of my fly research, I got mites in my stocks after years of never seeing a sign of them and I grew complacent. Big mistake. They are tough to purge.
I still have my old ‘fly pushing’ tool, and I shall never part with it. A heavy syringe needle with the tip flattened and bent, mounted onto the end of a small oval spatula. The perfect tool.
I always used a small watercolor brush with most of the bristles removed.
I certainly flipped a lot of flies in my time. It was particularly interesting when I worked with some of the “picture-winged” species that are indigenous to Hawaii. They require a strip of filter paper dipped in a particular plant extract placed in the culture vial to stimulate egg laying. Then, when the third instar larvae start “wandering” up out of the food, the vials are unplugged and placed in a large jar with coral sand in the bottom. The larvae pupate down in the sand. When adults emerge, you “vacuum” then up with a glass tube controlled by suction on a mouthpiece. It is handy to use a stopper penetrated by two glass tubes and that fits into the food vials. One tube connects to the glass probe that can capture flies and the other connects to a mouthpiece where you can apply suction. A vial acts as a trap in your suction line that retains the flies.
An ‘aspirator’. Used it to Hoover up small insects from a sweep net.
You appear to be describing the ‘pooter’, a key piece of apparatus for the entomologist:
https://simonleather.wordpress.com/2014/06/26/entomological-classics-the-pooter-or-insect-aspirator/
Now THAT is funny. 🙂
And I’d love to see a picture if possible
Yup, me too!
I can’t help but wonder how often the old Groucho joke was shared in these labs: “Time flies like an arrow; fruit flies like a banana.”
I’m sorry, I can’t tell the difference between cinnabar and vermillion. It’s a good thing I’m not a scientist in the field of genetics.
Just thinking about all those flies makes me itchy. Glad to have made a career in software and not fly-wrangling.
Fascinating. I had no idea that this type of lab/facility existed. Like others, I’d love to see a photo of the Groucho Marx fly.
Sadly, I didn’t take a photo. But I think you can find photos of the two mutations separately on the Internet.
Great stuff, thanks!
Who says people don’t read the science sections here? – that was excellent and I’ll read the Times article later. On that subject… I’ll never forget the bang my head on the table moment when that intellectual tower known as Sarah Palin trashed fruit fly research as “being a waste of your government’s money.”
It was classic Palin. And I’m not even a scientist, just well read.
It was at that moment I became terrified: “Damnit she’s stupid enough to WIN this election.”
Little did I know how downhill things would tumble 8 years later.
So my question to you is: Reagan, GWB, Palin, Trump: how much stupider can the stupid party get?
D.A.
NYC
https://whyevolutionistrue.com/2020/06/10/photos-of-readers-93/
A great example of how science is a huge collaborative effort with many different people and organisations contributing in various ways. We correctly honour those whose insights and years of research have advanced our understanding of the way nature works but it is good to see recognition also given to those whose contribution may be less glamorous but is nevertheless essential to the whole enterprise.
With regards to the collaborative nature of science it is sad to see how the UK’s (in my view) self-destructive departure from the European Union is putting British scientific collaboration with European scientists at risk.
Fascinating stuff.
It’s always been a worry in the back of my mind, what if D melanogaster and E coli are in fact completely atypical?
What if we just happen to have picked two very unusual species for so much genetic research?
I’m hoping that if this were true then it would have become obvious in recent years.
I guess there has been plenty of research on the genetics and developmental biology of a wide range of other species from various taxa. This has not shown either Drosophila or E coli to be misleading research models to use.