Cell division is one of the fundamental processes in all eukaryotes and plays a crucial role in growth and development of multicellular organisms. A 192-bp predicted DNA product was amplified from the genetic tumors of Nicotiana glauca-Nicotiana langsdorffii hybrid using degenerate primers specific for cyclin genes. A full-length cyclin cDNA clone was subsequently identified from the genetic tumors using a cDNA library screening strategy. In situ hybridization analysis showed that the GTcyc was detected in numerous, small spots in the whole range of genetic tumor.