SATELLITE DNA-SEQUENCES IN THE HUMAN ACROCENTRIC CHROMOSOMES - INFORMATION FROM TRANSLOCATIONS AND HETEROMORPHISMS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 33  (2) , 243-251
Abstract
Satellite III DNA was located by in situ hybridization in chromosomes 1, 3-5, 7, 9, 10, 13-18, 20-22 and Y and ribosomal(r)DNA in the acrocentric chromosomes 13-15, 21 and 22. In the acrocentric chromosomes, the satellite DNA is located in the short arm. The amount of satellite DNA in Robertsonian translocation and normal variant chromosomes was compared with that in their homologs by in situ hybridization. In almost all dicentric Robertsonian translocations, the amount of satellite DNA is less than that in the normal homologs, but it is rarely completely absent; satellite DNA is located between the centromere and the nucleolus organizer region (NOR) and the breakpoints are within the satellite DNA. The amount of satellite DNA shows a range of variation in normal chromosomes, and this is still more extreme in normal variant chromosomes, those with large short arms (p+ or ph+) generally having more satellite DNA than those with small short arms (p- or ph-). The cytological satellites are heterogeneous in DNA content; some contain satellite DNA, others apparently do not, and the satellite DNA content is not related to the size or intensity of fluorescence of the satellites. The significance of these variations for the putative functions of satellite DNA is discussed.