Pronuclear Microinjection

Every cell of a specific transgenic animal contains identical exogenous genetic material. A transgenic mouse or rat is a very useful system for studying mammalian gene function and regulation because analysis is carried out on the whole organism. Transgenic mice/rats are also used to model human diseases that involve the overexpression of a particular wildtype or mutated protein.

Taconic's Custom Transgenics Program employs pronuclear microinjection technology to create genetically-modified mice or rats transgenic founders. With pronuclear microinjection, a pre-designed gene (or genes) are injected, or co-injected, and then randomly integrated into the mouse or rat genome, with either single or multiple transgene copies at the site of insertion (i.e., gene dosage effect).

More Facts about Taconic's Custom Transgenic Program:

• Taconic has created more than 10,000 founder mice (and/or rats) from over 3,500 transgene constructs
• Taconic has an enviable, overall success rate of 98% in generating transgenic mice/rats.
• Taconic's transgenic mice/rats have been used within the scientific community around the world to study the biology of gene function(s) and establish numerous animal models of human disease.

Generating a transgenic mouse or rat is a multi-step process that involves:

1. Project design
2. Construction and purification of specific transgene constructs
3. Microinjection of fertilized eggs followed by embryo transfer

After embryo transfer, pups are born followed by genotype screening for the presence of the transgene. The entire process takes 12-18 weeks (see diagram below).

Depending upon our client's needs, Taconic's transgenic mouse program can employ a variety of mouse strains for transgenic production. These include:

For our clients wishing to develop transgenic rats, we are able to offer the following rat strains:

Taconic scientists are highly skilled at transgenic mice/rat production employing a variety of constitutive and tissue-specific transgene constructs. These include standard transgene constructs which are generally less than 40Kb in size, as well as much larger BAC and YAC (which may be supplied by the client or acquired/recombineered by Taconic) constructs. In addition, we can provide our clients with a number of key ancillary transgenic services such as the breeding of founder lines to germline transmission, gene copy number determination and/or integration site analysis, mRNA expression analysis by qRT-PCR/Northern blotting, protein expression analysis via Western Blot analysis, and various applications of FACS analysis. In addition, Taconic can also provide phenotypic analysis employing its PhenoTac™ technology which will enable our clients to obtain quicker and more cost-effective physiological data sets.