CHARACTERIZATION OF X-CHROMOSOME SPECIFIC SATELLITE DNA OF MUNTIACUS-MUNTJAK-VAGINALIS

A highly repeated DNA (designated satellite IA) was isolated from cultured cells of M. muntjak vaginalis and its organization analyzed by the use of restriction nucleases and hybridization experiments with cloned DNA-fragments. Several restriction nucleases cleave the satellite IA DNA into a series of fragments, which are multiples of a basic repeat unit of 800 bp [base pair]. Sequences homologous to the satellite IA DNA were aslo found in a 2nd highly repetitive DNA component of M. muntjak vaginalis (satellite IB). Its organization is more complex than the one of satellite IA and does not conform to a simple periodicity of a basic repeat unit. Hybridization in situ revealed, that both satellites are confined in their entirety to the X-chromosome, where they are located at both arms close to the centromere. No satellite DNA was found at the Y1-chromosome, which is considered to be homologous to the long arm of the X-chromosome. These results have interesting implications for the evolution of the X-chromosome.