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Biological Chemistry


Grumpy hamsters and clammed-up clams

by Sydney Smith
December 1, 2022 | A version of this story appeared in Volume 100, Issue 43


Hamsters lacking in holiday spirit

Two hamsters, one reaching out to the other with a boxing glove edited over its extended paw, as though the hamsters were duking it out (though neither is distressed).
Credit: Shutterstock/C&EN
A battle for truth: Hamsters would like us to know that their neural circuitry is more complex than previously thought.

What’s that under the tree, a teddy bear? Not the stuffed kind, but perhaps the third-most-exciting pet to unwrap, after the pony and the puppy: the teddy bear hamster! The teddy, technically Mesocricetus auratus, is also known as the Syrian or golden hamster and has a storied ancestry—though not quite a Christmas story.

Minding their own business in a cozy burrow 2.4 m beneath a wheat field in northeastern Syria, a family of 12 teddy bear hamsters were scooped out of their slumber back in 1930. The hamster-hunting expedition was led by Israel Aharoni and later documented in his Memoirs of a Hebrew Zoologist. He aimed to help his Hebrew University of Jerusalem colleague Saul Adler, who needed hamsters for parasite research, and to provide the first serious study of the species.

On that fateful spring afternoon, Aharoni and his tired workforce of local laborers were thus joyous—well, the latter were likely just relieved—to find the litter after having dug up most of the wheat field. The hamsters were collected, and after mishaps and mutinies, Aharoni eventually made it to the lab with the remaining two hamsters which had not mastered the art of escape.

Within 1 year, there were 150 hamsters. Adler shared them with other labs, even smuggling them into the UK in his coat pockets. How the first teddy bear hamster made it to the US in 1938 is murky, but at least some of them are thought to have originated in Adler’s colonies.

A full-blown hamster industry was founded in the US by Albert Marsh, who won one while gambling. Unemployed and recognizing the commercial potential for such small and cute creatures, he established Gulf Hamstery in 1946, which advertised the hamsters in Popular Science as “The new wonder animals[.] . . . Often called Toy Bears. Delightful pets. Everyone wants them. Laboratories need thousands.”

Labs still study the species today. In fact, in 1969, specially bred descendants of the hamstery were acquired by Charles River Laboratories, which happens to be where the critters in some recent hamster science originated.

Last year, Georgia State University researchers accidentally turned teddy bear hamsters into creatures . . . considerably less cuddly (Proc. Natl. Acad. Sci. U.S.A. 2022, DOI: 10.1073/pnas.2121037119). These were not hamsters you’d want to find under the tree.

Aiming to expand previous studies that suggest the hormone arginine vasopressin—along with its V1a receptor, Avpr1a—helps regulate social behavior, the scientists used CRISPR-Cas9 to spawn a line of teddy bear hamsters with nonfunctional Avpr1a genes.

Much to their surprise, the “teddy bears” acted more like grizzly bears, duking it out as if they were professional cage fighters (though safety was monitored in the lab). Indeed, those with inoperative Avpr1a genes—ironically dubbed Avpr1a knockout, or KO, hamsters—were twice as aggressive as their wild-type counterparts when placed in a neutral arena with a peaceful opponent. Further, when exposed to other hamsters’ odors, KO hamsters engaged in scent marking, to convey dominance or call dibs on a mate, twice as often as their counterparts did.

With these unanticipated behaviors, the study demonstrated the complexity of teddy bear hamsters’ neurocircuitry, the sum of which must be taken as greater than its nodes—or else. Admiring the intricacies of her own hamster, Squirt—and hoping to keep him happy—this Newscriptster will be giving her pet extra treats this holiday season.


Clams, a strong, silent type

The clam Cymatioa cooki as it was found living in the foreshore near Naples Point in California, after having been assumed to have been extinct for approximately the past 40,000 years.
Credit: Jeffrey H. R. Goddard
Opening up: This clandestine clam is ready to show itself.

A stealthy species of clam, Cymatioa cooki, has been discovered—alive! The clammed-up creature, thought to have been extinct for tens of thousands of years, had been encountered only in fossilized form before the sighting under a rock near Naples Point, California (ZooKeys 2022, DOI: 10.3897/zookeys.1128.95139).

What has this too-cool clam been up to in the meantime? Well, scientists can’t be certain, but this must be one tough cooki. As the late Shel Silverstein wrote, “You may leave the clam on the ocean’s floor, / It’s all the same to the clam. / For a hundred thousand years or more, / It’s all the same to the clam.”

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