SSS 2011-03-04

（单词翻译）

Every villain¹ has his Achilles' heel. And microscopic² scoundrels are no exception. The challenge for those who wish to ward³ off microbial bad guys is to identify that weak spot. Now, scientists studying the toxoplasmosis parasite⁴ think they've done just that. They share the secret in the Proceedings⁵ of the National Academy of Sciences.

The toxo parasite is similar to the one that causes malaria⁶. So finding a way to prevent these rogues⁷ from reproducing is high on researchers' to-do lists. The bugs⁸ are tricky⁹ to take down, in part because they're unpredictable in the way they multiply. Sometimes they get in and get busy making babies. Other times they copy their chromosomes¹⁰ but hold off parceling them out to their army of offspring until the time is right.

This flexibility¹¹ has benefits, but it also has a drawback: the parasites¹² have to keep track of their chromosomes…even as they change their minds about how and when to divvy them up. Now scientists have discovered a structure…unique to these parasites…that keeps their DNA¹³ in a tidy bundle through thick and thin. Find a drug that breaks that bundle, and we could destroy these parasites' devious¹⁴ plans.

Thanks for the minute. For Scientific American's 60-Second Science, I'm Karen Hopkin.