Wheat specific repetitive DNA sequences - construction and characterization of four different genomic clones.

The construction and molecular analysis of four recombinant clones - pTa1, pTa2, pTa7, and pTa8 - is described. The four clones contain different highly repeated sequences of genomic DNA from Triticum aestivum variety 'Chinese Spring'. The wheat specificity has been determined by colony and dot blot hybridization in comparison with total rye DNA (Secale cereale variety 'Petka'). The four clones with a variable degree of specificity were compared by sequence analysis after the recloning of wheat DNA inserts into M13 mp8. Within the sequencing data a tendency can be observed that those repeated sequences which show the highest degree of species specificity contain a significantly increased amount of GC residues.