DNA Methylation
Transcriptional repression is an essential mechanism in the precise control of gene expression. Transcriptional repressor proteins associate with their target genes either directly through a DNA-binding domain or indirectly by interacting with other DNA-bound proteins.
http://www.imgenex.com/DNAMethylation.php

Lichens and Me by Katalin Molnar
This website is about lichens (symbiotic organisms). It contains brief description, publication, photos about them and also refers to other sites with lichenological interests.
http://katalinmolnar.com/