Comparing Transgene vs. Gene: Mechanisms & Effects

[Pythagorean]

Is transgene only a statement of the history of a gene (that it did not develop through selection in the organism)

OR

is a transgene mechanistically different (i.e, does the transgene embed itself into the genome of the host organism and from then on act as if it were any other gene in the DNA strand or does it have a different way of being picked up and used in translation?)

I'm thinking of vectors now, specifically. Do vectors incorporate into the host organisms's DNA before being used? Are they then there forever (I understand that they're likely not in the sex cells, so the phenotype will not get passed on to progeny) in the organism?

Or do vectors float around in the cell and get used by Ribosomes for translation independent of the host organism's main DNA processes?

 

[atyy]

It can happen that foreign DNA gets incorporated into the host chromosome, as in yeast transformation.

However, there are also plasmids that are translated using the host translational machinery without integration.

Somatic DNA can also be naturally rearranged in VDJ recombination.

In transgenic mice, the transgene is incorporated into a "random" locus in the host chromosome.

In knock-in mice (which most consider not "transgenic mice", but terminology is not completely universal), the transgene is incorporated into a specific locus in the host chromosome.