Expert: Dana Krempels, Ph.D. - 12/7/2007

Question
What was the reasoning behind naming heterochromatin heterochromatin?

Answer
Dear Maurice,

I can't find this in any of my dozen or so Genetics textbooks, either.  So how about an educated guess?

As you know, there are two known forms of chromatin, euchromatin and heterochromatin. The former is believed to contain DNA that's actively transcribed and translated, whereas heterochromatin, tightly supercoiled, is transcribed and translated to a lesser degree, or not at all.

The Greek prefix "eu" means "true."  The Greek prefix "hetero" means, literally, "other" or "different."  The folks who coined the terms may just have not been feeling very creative that day, and named the two "true chromatin" and "other/different chromatin" simply to indicate that the two were physically different.

But that's just a guess.  :)

Hope that helps.

Dana