Learn why fragrance-free is NOT the same as unscented and how a cow named Cosmo was genetically edited so he’ll have more male offspring.
Learn why fragrance-free is NOT the same as unscented, and how a cow named Cosmo was genetically edited so he’ll have more male offspring.
There's a big difference between "unscented" and "fragrance free" by Kelsey Donk
Cow's genome was edited to make him produce more male offspring by Grant Currin
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/difference-between-unscented-fragrance-free-and-cow-gene-editing-for-more-male-offspring
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn why fragrance-free is NOT the same as unscented, and how a cow named Cosmo was genetically edited so he’ll have more male offspring.
CODY: Let’s satisfy some curiosity.
When you’re buying personal care or household products, there are lots of reasons you might go “unscented” or “fragrance-free”. Some people are sensitive to smells, others have allergies, and still more just don’t want to smell like a jumble of all the products they use! But did you know that there's actually a big difference between what it means for a product to be "unscented" and what it means to be "fragrance-free”?
If you didn’t, you’re not alone. Take it from a survey performed by the Natural Marketing Institute and Johnson and Johnson, the maker of a whole bunch of body products. They asked fragrance-free consumers to take pictures of their personal care products and indicate whether they thought the products were unscented or not. The consumers were wrong about half the time. Most of these people had fragrance sensitivities, and some had even been diagnosed with a fragrance allergy, and they still didn’t know which of their own products were scented!
The confusion is understandable. That’s because it’s all a big word game. Basically, an “unscented” product is supposed to have no smell at all. But because many ingredients have a smell, unscented products often have a “masking” scent added to give the illusion that they have no scent.
A “fragrance-free” product, however, can actually have a smell — the smell just has to be there by accident. So if you’re making a moisturizer you want to label as “fragrance-free,” it’s not a problem if the oil you want to use as an emollient also happens to have a scent. As long as you’re using it for an emollient and not for fragrance, that product can still be labeled as fragrance-free. It couldn’t, however, be labeled as unscented.
That can be tricky for people who have sensitivities or allergies. Fragrances can be made up of hundreds of different components, and they don’t all have to be indicated on ingredient labels. So what’s a fragrance-sensitive person to do? Well, in the U.S., you could look for products bearing the EPA’s “Safer Choice” fragrance-free label. That means the product has passed certain guidelines for human health, and that it doesn’t contain fragrance or masking scents.
But beyond that, it may just be a matter of trial and error. Fragrance sensitivities often have a mix of physiological and psychological causes, and it may not be possible to identify the exact compounds causing them. So if a certain product doesn’t agree with you, throw it out and look for something different. Listen to your nose, and you may start to breathe easier.
Ranchers like male cattle more than female cattle. They don’t mean anything by it; it’s just that male cattle eat less feed per pound of meat they produce. They’re more fuel-efficient, basically. It’s only a difference of about 15 percent, but that was enough to get scientists wondering how they could breed cattle that would produce more male calves than females.
That’s how Cosmo came about.
You see, Cosmo is a bull calf who was born in April of this year with some very unusual qualities. His genome was edited so that 75 percent of his offspring will be male.
How’d the researchers pull off this feat? If you follow molecular genetics, you might already have a guess: it’s CRISPR, the gene-editing tech that lets scientists use molecular scissors to cut genetic code out of a cell’s genome — or add new genetic code into it. In Cosmo’s case, the researchers chose the latter. When Cosmo was just an embryo himself, he got an extra copy of the SRY gene. That’s the string of A’s, T’s, C’s, and G’s that causes an embryo to start developing into a male.
Inserting a copy of the SRY gene into an embryo was not a simple task. After two-and-a-half years of trial and error, the researchers finally managed to insert the SRY gene into chromosome 17, in what’s called a genomic safe harbor site. That’s a place where the extra gene won’t cause problems for the naturally occurring genes that are nearby. But chromosome 17 wasn’t their first choice. What the researchers really wanted was to put it in the X chromosome. If that had happened, all of Cosmo’s offspring would have developed like males. Half would’ve inherited a Y chromosome and turned out male the old fashioned way. The other half would’ve inherited his X chromosome, which would normally make them female — but thanks to the SRY gene, they’d develop as males.
But in the end, things worked out a little differently because the researchers had to settle for chromosome 17. If everything goes to plan, half of Cosmo’s kids will inherit a Y chromosome and be normal males. And what about the offspring that inherit an X from their dad? Half of them won’t get Cosmo’s extra SRY gene, so they’ll develop as females. The other half will get the gene, so they should develop like males.
While the idea that we’re genetically editing livestock can feel a little unsettling, the researchers say this could benefit the environment in the long run. With more fuel-efficient cattle, you’d need fewer animals for the same amount of beef. Considering that livestock produce nearly 15 percent of all human-driven carbon emissions, cutting down on cattle would definitely be a good thing for the planet.
Let’s recap today’s takeaways
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CODY: Today’s stories were written by Kelsey Donk and Grant Currin, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Scriptwriting was by Cody Gough, and Natalia Reagan. Curiosity Daily is produced and edited by Cody Gough.
ASHLEY: Today’s episode was produced and edited by Cody Gough.
CODY: Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!