Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Nap1-mediated deposition of histones H2A and H2B on Xenopus sperm chromatin. This process can be modulated by karyopherin Kap114. DNA is stained with Hoechst (left column). The deposition of tetramethyl rhodamine isocyanate-labeled H2A/H2B (middle column) and RCC1-green fluorescent protein (right column) is seen only in the presence of Nap1 (compare first and second rows). Addition of recombinant Kap114 inhibits the loading of both histones and RCC1 (third row), while a control protein does not affect the reaction (bottom row). (See related article on p. 1764.)