Services

• Mouse and Rat Microsatellite and SNP Genotyping Supporting Marker-Assisted Backcrossing (Speed Congenics)
  
• Genetic Background Characterization of Genetically Engineered Mouse Lines
• Mouse and Rat Cell Line Characterization
• Passenger Mutation Analysis (e.g., Crb1<rd8>; Nnt deletion, etc.)
• H2 (MHC) Haplotyping and PCR Sex Determination
• PCR Testing for Rodent Infectious Agents
• Consultations in Rodent Genetics

Mouse and Rat Microsatellite and SNP Genotyping Supporting Marker-Assisted Backcrossing (Speed Congenics)
Transgenic and targeted mutants (e.g. knock-ins and knock-outs) often need to be transferred to a more suitable inbred background for phenotypic analysis orin order to mend an laready mixed background (for example, as commonly results from crossing cre-expressing lines with floxed-allele  lines). Traditional congenic strain development requires a series of backcrosses between the donor strain carrying the mutation and a recipient strain with a defined genetic background, typically an inbred strain, over many successive backcrosses, taking from three to five years. Marker-assisted (speed congenic) protocols can reduce the number of backcross generations from 10 to five and can be completed in 18 months..

Mouse and Rat Cell Line Characterization
Cross-contamination or misidentification of cell lines is a serious problem that is expected to be as widespread in rodent cell lines as it is in human cell lines (15-30% misidentified or contaminated).  LAGS offers short tandem repeat (STR), and single nucleotide polymorphism (SNP) analysis for mouse and rat cell line characterization. The core's PCR-based technique identifies the inbred strain from which the cell line was derived and rules out cross-contamination with other cell lines, but will not conclusively identify a particular cell line. For example, DNA from a pure B16 melanoma cell line will have a C57BL/6 profile reflecting its origin, but  will not be distinguished from the LLC cell line, also established from C57BL/6. For ES cell line characterization, please use our Background Characterization service.

Passenger Mutation Analysis
Passenger mutations are mutations that are hidden in the genomes of substrains and potentially affect experimental outcomes. These mutations typically arise through genetic drift that occurs when populations, derived from the same original inbred stain, are separated. Over time, this separation results in spontaneous mutations resulting in new and unique phenotypes. For example, mice of the C57BL substrain C57BL/6N  (NIH) but not C57BL/6J (JAX) are homozygous for a single nucleotide deletion of Crb1 (rd8 mutation) that renders them inadequate for behavioral studies requiring vision. In the case of mixed or unknown backgrounds , these mutations can produce unusual or unexpected results. LAGS offers specific genotypes for these mutations: Crb1 (rd8), Nnt, Skint1, Casp4, Gpr84, Patch1 and Pde6b (rd1).

Mouse H2 Haplotyping and Sex Determination
LAGS offers a PCR-based assay to determine the Major Histocompatibility Complex (H2) haplotype for your mice. This information is useful for projects involving tissue grafts between genetically modified or mutant mice with undefined H2 haplotypes, to help prevent graft rejection and graft-versus-host disease. The core also offers a PCR assay for accurate sex determination in mice. 

PCR Testing for Rodent Infectious Agents
We offer infectious diseases testing for the following agents: Syphacia obvelata and Aspiculuris tetraptera (pinworms), Myocoptes musculinus, Myobia musculi, and Radfordia affinis (fur mites) Helicobacter spp., and Campylobacter spp.  Tests for other infectious agents can also be developed and implemented according to your specific needs. 

Consultations in Rodent Genetics 
Core personnel also provide general information in mouse and rat genetics. These include: standard nomenclature for inbred strains and rodent genes and proteins, selection of the appropriate inbred background, development of genetic crosses, linkage analysis for simple genetic traits, etc.