please HELP me why this happen in transgenic mouse

[chunshu26]

i am studying genetics recently, i tried to understand how to make transgenic mouse model, but i always do not understand why when we got the transgenic mouse . we always get tandemly arranged copies in the transgenic mouse genome but not single copy ,on the contrary the sigle copy of the gene could be inserted randomly into chromosome when we use Drosophilia model.....
please help me find the answer of the questions.....thank you very much.[/i]

[b_d_41501]

I sort of do not understand the question as it is worded?? Transgenic in itself is defined as a genetically modified organism. Thus, things will not usually be orderly.

[GreenDog]

Trasgenic mice are made using homologus recombination, so you get only one copy of the gene in a specific location.

[chunshu26]

:roll: i am studying genetics recently, i tried to understand how to make transgenic mouse model, but i always do not understand why when we got the transgenic mouse . we always get tandemly arranged copies in the transgenic mouse genome but not single copy ,on the contrary the sigle copy of the gene could be inserted randomly into chromosome when we use Drosophilia model.....
please help me find the answer of the questions.....thank you very much.[/i]

i looked for the answe in some developmental books but failed..they only explain they will not be avoided only you manipulate the transgene into the mouse......so that perhaps means no answer for it......
still thanks a lot GreenDog and b_d_41501