Abstract
Meiotic pairing has now been shown to require heterochromatic homology and to be sensitive to repeat number in both male and female Drosophila. The increased pairing ability of repetitive sequences could be one reason that most eukaryotes allow the accumulation of tandem repeated elements. This may well be a reflection of a general role for heterochromatin, and at least a partial explanation of the ubiquity of heterochromatin through the eukaryotes.
