Uptake and binding of cytoplasmic DNA by wheat embryo cell nuclei.

Cytoplasmic non-mitochondrial DNA was selectively labelled and isolated In a linear single-stranded form from early wheat embryos. The isolated preparation was readily taken up by wheat embryo cell nuclei and firmly bound to large, chromosome-like structures. Similarly prepared nuclear DNA fragments, although taken up, remained unbound and underwent a rapid degradation within the cell nuclei. The selective binding of the cytoplasmic DNA indicates that it might be integrated into the nuclear genome.