Identification of an Indian muntjac DNA fragment preferentially hybridizing to the X-chromosome

Upon digestion of DNA from male and female Indian muntjac (Muntiacus muntjak) fibroblasts with the restriction enzyme Hae III or Alu I, a prominent fragment of DNA (greater than 20 kb in length) was observed. This excluded DNA (ex-DNA) appeared not to contain sequences recognized by a variety of restriction enzymes and constituted about 0.6% of the total DNA in the female genome. For equal amounts of DNA digested, female DNA contained more of this material. In situ hybridization indeed revealed strong hybridization of the ex-DNA to the entire X chromosome with a few less intense sites of hybridization on other chromosomes. Hybridization studies against total muntjac DNA indicated the presence of repetitive sequences in the ex-DNA. These repetitive sequences did not cross-hybridize with human or mouse DNA.