Transgene silencing:

• Expression of transgene is either very poor or absent.
• The main reasons are:

a) Lack of adequate promotor or enhancer strength.

b) Problems with the base sequence of transgene.

c) Introduction of the additional copies by transformation of genes.

d) Integration of transgenic heterochromatin region or it activates an undesirable gene.

Solutions to overcoming transgene silencing

a) Integrating a suitable and stronger promoter/enhancer sequence in an appropriate place in the DNA.

b) Modifying the base sequence without affecting the amino acids sequence of the encoded protein.

c) Placing the transgene in diverse genetic backgrounds.