11 June 1999
Vol 284, Issue 5421

About The Cover

Cover image expansion

COVER In mammals, flies, and nematodes, a specialized dosage compensation complex equalizes the expression of genes on the X chromosome between 1X males and 2X females (or hermaphrodites) by modulating transcript levels. In Caenorhabditis elegans, SDC-2 protein (red) targets the complex along the X chromosomes of hermaphrodite embryos (~50 mm long) (DNA in blue) at about the 40-cell stage. A mating pair (~1 mm long) is on the left. See page 1800 [Images: H. Dawes and A. Villeneuve]