Production of somatic mosaicism in mammals using a recombinatorial substrate

A method of producing a transgenic mammal whose somatic and germ cells contain a recombinatorial substrate, comprising:

• providing a recombinatorial substrate, comprising:
• a promoter element capable of promoting transcription of genes in the recombinatorial substrate;
• a gene whose expression is to be controlled, said gene being positioned 3′ to the promoter element to facilitate its transcription;
• a terminator positioned 3′ and 5′ to said gene whose expression is to be controlled to said promoter to prevent transcription of genes 3′ to said terminator;
• and
• a first recombination site located 3′ to said terminator and a second recombination site located 5′ to said terminator, whereby treatment of said DNA molecule with a recombinase specific to said recombination sites removes said terminator from said DNA molecule, thereby permitting transcription of said gene whose expression is to be controlled;
• introducing the recombinatorial substrate into an embryo;
• transplanting the embryo into a pseudopregnant mammal and allowing the transplanted embryo to develop to term;
• and
• identifying a mammal which carries the recombinatorial substrate.

A method of activating a gene to be expressed in a recombinatorial substrate, comprising:

• providing a transgenic mammal carrying a recombinatorial substrate, comprising:
• a promoter element capable of promoting transcription of genes in the recombinatorial substrate;
• a gene whose expression is to be controlled, said gene being positioned 3′ to the terminator element to facilitate its transcription;
• a terminator positioned 3′ to said promoter and 5′ to said gene whose expression is to be controlled to prevent transcription of genes 3′ to said terminator;
• and
• a first recombination site located 3′ to said terminator and a second recombination site located 5′ to said terminator, whereby treatment of said DNA molecule with a recombinase specific to said recombination sites removes said terminator from said DNA molecule, thereby activating the recombinatorial substrate and permitting transcription of said gene whose expression is to be controlled;
• introducing into the transgenic mammal a recombinase which will promote the excision of DNA from said first recombination site to said second recombination site within the recombinatorial substrate;
• and
• identifying a mammal which contains an activated recombinatorial substrate.

A DNA molecule encoding a recombinatorial substrate comprising:

• a promoter element capable of promoting transcription of genes in the recombinatorial substrate;
• a gene whose expression is to be controlled, said gene being positioned 3′ to the promoter element to facilitate its transcription;
• and
• a first recombination site located 3′ to the gene whose expression is to be controlled and a second recombination site located 5′ to the gene whose expression is to be controlled, whereby treatment of said DNA molecule with a recombinase specific to said recombination sites removes said gene whose expression is to be controlled from said DNA molecule, thereby activating the recombinatorial substrate and resulting in a loss of function of said gene whose expression is to be controlled.

A method of producing a transgenic mammal whose somatic and germ cells contain a recombinatorial substrate, comprising:

• providing a recombinatorial substrate, comprising:
• a promoter element capable of promoting transcription of genes in the recombinatorial substrate;
• a gene whose expression is to be controlled, said gene being positioned 3′ to the promoter element to facilitate its transcription;
• and
• a first recombination site located 3′ to the gene whose expression is to be controlled and a second recombination site located 5′ to the gene whose expression is to be controlled, whereby treatment of said DNA molecule with a recombinase specific to said recombination sites removes said gene whose expression is to be controlled from said DNA molecule, thereby resulting in the loss of function of said gene whose expression is to be controlled;
• introducing the recombinatorial substrate into an embryo;
• transplanting the embryo into a pseudopregnant mammal and allowing the transplanted embryo to develop to term;
• and
• identifying a mammal which carries the recombinatorial substrate.

A method of activating a gene to be expressed in a recombinatorial substrate, comprising:

• providing a transgenic mammal carrying a recombinatorial substrate, comprising:
• a promoter element capable of promoting transcription of genes in the recombinatorial substrate;
• a gene whose expression is to be controlled, said gene being positioned 3′ to the promoter element to facilitate its transcription;
• and
• a first recombination site located 3′ to the gene whose expression is to be controlled and a second recombination site located 5′ to the gene whose expression is to be controlled, whereby treatment of said DNA molecule with a recombinase specific to said recombination sites removes said gene whose expression is to be controlled from said DNA molecule, thereby activating the recombinatorial substrate and resulting in a loss of function of said gene whose expression is to be controlled;
• introducing into the transgenic mammal a recombinase which will promote the excision of the DNA from said first recombination site to said second recombination site within the recombinatorial substrate;
• and
• identifying a mammal which contains an activated recombinatorial substrate.