Absence of satellite III DNA in the centromere and the proximal long-arm region of human chromosome 14: analysis of a 14p- variant.

Cytogenetic methods and molecular probes derived from the centromere and short arm of chromosome 14 were used to investigate the structural properties of a chromosome 14 variant. Results of GTL, CBG, Ag-NOR, and nonbanded Giemsa staining of the chromosomes suggested the complete absence of the short arm and possibly a large part of the centromere. Negative in situ hybridisation with an a satellite III probe confirmed the absence of the arm; the detection of normal amounts of alpha-satellite DNA, however, indicated retention of the centromeric domain. The natural occurrence of a human acrocentric variant lacking a short arm was thus established. Within the detection limits of the methods used, the results demonstrate that satellite III DNA is not essential for norma! centromeric activity and allow us to exclude the presence of this satellite DNA within the centromere and proximal long-arm region of human chromosome 14.