Whether or not the story is true, the symbolism of the thistle (ahem, sorry for the pun) took root and is honored to this day. Other facts about the thistle include that it is a biennial plant, meaning it takes two years to complete its life cycle. It reseeds easily. It's a combination of beauty and ruggedness. It has a spreading, invasive root system, hence its classification as weed.
imprinted gene, a gene whose expression has been affected by genomic imprinting so that only a single allele functions, the other being turned off by epigenetic mechanisms during embryonic development.
Genomic imprinting is an epigenetic mechanism of inheritance which allows genes to be expressed differently depending on which parent they come from. This means it is modification of the genome, or changes what the genome produces, without changing the nucleotide (DNA) sequence.his is the one of the first evidences of genomic imprinting discovered. In the first part of the diagram a mutant gene trying to make the mouse offspring dwarf is passed from the mother. It can be seen that the mouse is not dwarf because the allele for size in this mouse is an imprinted.