ORGANIZATION OF THE VARIANT DOMAINS OF ALPHA-SATELLITE DNA ON HUMAN CHROMOSOME-21

The de novo creation of long, homogeneous, satellite DNA domains was p ostulated previously to occur by saltatory amplification. In this pape r, pulsed field gel electrophoresis analysis of the alpha satellite DN A block organization of the human chromosome 21 supports this hypothes is. Double-dimension electrophoresis indicated that the variant copies of the basic alpha satellite repeat of chromosome 21 are organized in a single 3,150 Kb-long domain. It was also established that the other satellite DNAs found in man (beta, II, and III) are organized indepen dently of the alpha satellite DNA block of the same chromosome.