ABSTRACT
A substantial fraction of DNA in W chromosomes of chickens, turkeys, and pheasants consists of repetitive families that are unique to this female-specific sex chromosome. Repeating units of these families share common sequence organization, and they all behave as strongly bent DNA in solution. These units are useful probes in sexing of early embryos by DNA/DNA hybridization. Application of this technique to the study of gene expression concerning sex steroid hormone synthesis during sex differentiation of the chicken is described. In addition, a cDNA clone derived from a gene on the Z chromosome and expressed in the chicken ovary is described. Finally, future research involving these sex chromosome-specific DNA sequences is discussed.
