Excerpt:

A fascinating scientific discovery could finally help us solve the problem of stray cats reproducing out of control.

The custom adenovirus AAV9-fcMISv2 is designed to prevent stray cats from reproducing. The virus causes few symptoms and feels “just like a cold.”

In the new study, Pépin, Swanson, and colleagues inserted the cat version of the AMH gene into a harmless virus widely used in gene therapy to ferry replacement genes into cells.

Scientists designed “gene therapy” that makes female cats immune to their reproductive organs and eggs. They discovered that making feline bodies produce a so-called “antimüllerian hormone” would stop reproductive processes.

That changed when an unusual pair of scientists came together. David Pépin, a reproductive biologist at Massachusetts General Hospital, spent his early career researching antimüllerian hormone (AMH), which is produced by follicles in the ovary that give rise to eggs. When, in one experiment, he amped up the expression of the hormone in female mice, their ovaries stopped forming follicles, sterilizing the animals.

The adenovirus expressing this hormone (abbreviated AMH) works so well that female felines lose interest in mating. Despite putting males and females in one cage for extended periods, females displayed a reduced desire to mate, and no kittens were born even when mating took place, as the Nature article explains:

However, when estrus is defined behaviorally by the female permitting mounting and coitus, an effect of treatment can clearly be observed. All three control females mated repeatedly with both males, whereas four of the six treated females rebuffed every mating attempt by the breeder males during both mating trials (Table 1 and Supplementary Tables 1 and 2).

In contrast, no AAV9-fcMISv2-treated females gave birth during either trial and no gestational sacs or fetuses were observed at weekly ultrasound exams. Because no kittens were born from treated females, we did not assess maternal-fetal transmission of AMH.

I guess having fewer stray cats is a good thing. And yet, think about the possibilities: someone could design another virus that infects humans, which would render us infertile.

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