Biopolymers and cell. 2000; 16 (3): 220 - 224

Methylation variability of external cytosine of CCGG-sequences in DNA of sunflower shoots and meristem callus

E. N. Tishchenko, L P. Korzh

External cytosine of CCGG-sequences in DNA of undifferentiated cells of meristems primary calluses in sunflower (Helianthus annuus L.) snoots and roots is highly methylated. During the growth and differentiation of shoots of etiolated seedlings the extensive undermethylation of this palindromic site in DNA, correlating with the transcription of tissue-specific genes, has been observed. The variability of methylation of CCGG-sequences of DNA assumes that enzymatic modification of cytosine takes part in cell differentiation, perhaps, on the level of gene expression.