Human hamster

What does the golden hamster have to do with human fertility tests?

Sqrt (Andreas Hein) [CC BY 3.0], via Wikimedia Commons
Six months ago I wrote about the dead rabbit pregnancy test, an early 20th century technique to determine whether someone was pregnant by injecting their pee into a rabbit. It turns out that this is not the only fertility-related diagnostic tool that involves animals.

When evaluating male infertility, one test involves hamster eggs. Specifically, the ovum of a golden / Syrian hamster. The hamster’s eggs are removed and stripped of their protective outer casing (the zona pellucida). Then human sperm are added and the interspecies mixture is left for a few hours. Then the eggs are examined to see how many human sperm have penetrated the hamster egg.

And, get this, not only do the sperm penetrate the egg, but they actually fertilise it: a single cell hybrid is created (and then immediately destroyed, because we do not want human hamsters wandering around).

Here’s the thing, though. I was hesitant about writing this post. Anti-science people take interesting phenomena like this and pretzel them around into… well, anti-science propaganda. I’m not anti-science, and I’m not anti-this-test. I just think it’s a really unusual and interesting case of cross-species fertilisation! It has never gone beyond a single cell line, been implanted, or done anything except advance our knowledge of biology. There’s no evidence that it could go further than that single cell, and no-one is trying to take it further. So it’s just a neat footnote to health and medicine.

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