Mapping and tandem arrangement of DXZ4 in primates. (a) Direct-labeled fluorescence in situ hybridization (FISH) of human DXZ4 BAC clone (2272M5; red) and human PLS3 BAC clone (268A15; green) to male and female rhesus macaque metaphase chromosomes. White arrows point to the hybridizing X chromosome. Metaphase chromosomes were counterstained with DAPI, and converted to gray-scale to assist in visualizing the FISH signals. (b) Southern blot of XbaI digested primate genomic DNA separated by pulsed field gel electrophoresis, hybridized with a human digoxigenin-labeled DXZ4 probe. Primates and group are listed along the top and gender indicated by M (male) or F (female), including rhesus macaque (R. Macaque), pig-tailed macaque (P-T. Macaque), common squirrel monkey (Sq. Monkey) and black-handed spider monkey (Sp. Monkey). Size in kilobases is given to the left. (c) Ethidium bromide stained 0.9% agarose gel showing green monkey and macaque BAC DNA digested with the restriction endonuclease HindIII and separated by gel electrophoresis. The sizes of the molecular weight marker are given to the left in kilobases.