CHARACTERIZATION OF A CHROMOSOME-SPECIFIC CHIMPANZEE ALPHA-SATELLITE SUBSET - EVOLUTIONARY RELATIONSHIP TO SUBSETS ON HUMAN-CHROMOSOMES

Alpha satellite DNA is a tandemly repeated DNA family found at the cen tromeres of all primate chromosomes examined. The fundamental repeat u nits of alpha satellite DNA are diverged 169- to 172-bp monomers, ofte n found to be organized in chromosome-specific higher-order repeat uni ts. The chromosomes of human (Homo sapiens (HSA)), chimpanzee (Pan tro glodytes (PTR) and Pan paniscus), and gorilla (Gorilla gorilla) share a remarkable similarity and synteny. It is of interest to ask if alpha satellite arrays at centromeres of homologous chromosomes between the se species are closely related (evolving in an orthologous manner) or if the evolutionary processes that homogenize and spread these arrays within and between chromosomes result in nonorthologous evolution of a rrays. By using PCR primers specific for human chromosome 17-specific alpha satellite DNA, we have amplified, cloned, and characterized a ch romosome-specific subset from the PTR chimpanzee genome. Hybridization both on Southern blots and in situ as well as sequence analysis show that this subset is most closely related, as expected, to sequences on HSA 17. However, in situ hybridization reveals that this subset is no t found on the homologous chromosome in chimpanzee (PTR 19), but inste ad on PTR 12, which is homologous to HSA 2p. (C) 1996 Academic Press, Inc.