(IMAGE) Nara Institute of Science and Technology Caption Changes in histone modifications of genes involved in flowering. (a) The removal of Polycomb complexes by SDG7 protein. (b) Transcription elongation and the deposition of H3K36me3 by SDG8 protein. PRE: Polycomb Response Elements. Purple: H3K27me3. Green: H3K36me3. Credit Nobutoshi Yamaguchi Usage Restrictions Credit required License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.