• Mouse Transgenics

Transgenic mice are produced by the microinjection of DNA constructs into the pronuclei of 0.5 dpc (days post coitum) one-cell fertilized eggs. The injected eggs are transferred to the oviducts of 0.5 dpc pseudopregnant foster mothers. The DNA construct will integrate randomly into the genome of the egg and the resulting founder mice will contain one or more copies of the transgene in every cell. Small tail tissue samples are isolated from each founder mouse for DNA genotype analysis. Mice determined to be transgenic for the injected DNA are shipped to the client.

• Mouse Gene Targeting

Gene targeted, "knock-out" or "knock-in", mice are produced by injecting blastocysts with embryonic stem (ES) cells that have been genetically modified. Embryonic stem cells are pluripotent stem cells that are derived from the inner cell mass of 3.5 dpc embryos called blastocysts. These undifferentiated cells have the capacity to differentiate into most tissues of the mouse. Typically, 129/SvJ strain ES cells are transfected by electroporation with an isogenic DNA construct containing homology to a region of the genome. By a process called homologous recombination, this DNA fragment will insert into the homologous gene either "knocking out" the function of the gene or "knocking in" a functional gene into the same locus. The transfected cells are placed in a selective media and the surviving clones are isolated, grown in culture, replicated and one replicate placed in frozen storage. The cells of one replicate are processed for DNA isolation and the clones testing positive for homologous recombination are thawed and expanded. These positive clones are injected into blastocysts, from a donor mouse, that are implanted into pseudopregnant foster mothers. Chimeric offspring are backcrossed to test for germline transmission of the targeted gene. Heterozygous mice are then intercrossed to derive homozygous gene targeted mice.

• Xenotransplantation

With recent advances in identifying candidate genes involved during different stages of tumor formation, there is a great need to validate the role of these genes in the etiology of tumors and their malignant progression. The most rapid means to do this in a relevant in vivo model is to use the established cell lines, typically of mouse or human origin, engineered to over- or under- express the gene(s) of interest. Upon injection into immune compromised mice (such as athymic nude or SCID mice), these cells have the potential to form tumors without host immune interference at ectopic or orthotopic sites depending upon the route of cell injection. The tumorigenic properties of these cells can be analyzed over time, and important attributes such as metastatic propensity and the degree of angiogenesis determined. Furthermore, potential therapeutics can be tested against the cell lines harboring the particular genetic aberration in an in vivo model.

• Cytogenetics 
  

The cytogenetics laboratory uses both cytogenetic and molecular genetic techniques to identify structural and numerical chromosomal aberrations associated with mammalian disease.  The services provided include advanced molecular cytogenetic techniques such as fluorescent in-situ hybridization (FISH), spectral karyotyping (SKY), and transgene localization, along with routine karyotyping (G-banding), chromosomal breakage studies, and mouse embryonic stem (ES) cell trisomy 8 screening.

• Embryo Cryopreservation

Mouse embryo cryopreservation is a method for archiving and reconstituting valuable strains. This cost effective method decreases the need to continuously breed valuable mouse models. It provides added insurance against genetic drift, loss of the custom mouse lines due to disease outbreak, or a catastrophic event. The frozen strains can be reconstituted at any time by implantation into the oviducts of recipient mice.

• Other Services
  Necropsy
  Imaging and Microscopy
  Veterinary Pathology
  Robotic DNA isolation
  Mouse Rederivation
  Animal Housing Services
  Animal Technical Services
  Contract Breeding Services
  Cancer Model Repository
  
  

CONTACT:

Mr. Tom DeKoning, Marketing Manager, CTA Corp CTACorp@vai.org

Pamela Swiatek, Ph.D., M.B.A., Director, Senior Scientific Investigator, (VARI) pam.swiatek@vai.org