Strain Prefixes (Pedigree Prefix)
When registering genetically modified and other animals, the prefix must provide clear information about the strain and the affected genes:
- Genetically modified animals: The prefix must contain information about the affected gene.
- Important: Avoid using generic terms such as tg, ko, or fl in the prefix itself.
- Other animals: The prefix should contain the relevant part of the strain name.
- Commercial wild types: Wild types purchased from commercial suppliers must be listed with their full strain name.
The strain name must either be a correct representation in accordance with nomenclature rules, or a correct name for the background of the genetic modification. This is particularly important for research groups using the same modification on more than one background.
Note: Tasks or orders that cannot be executed in accordance with these specifications will be marked in black by the KM staff.
Guidelines for Genotypes
The genotype field is intended to describe a single locus.
Standard Abbreviations
Use the following abbreviations in the genotype field:
- tg: Presence of the transgene specified in the prefix
- ko: Knockout allele
- fl: Floxed allele
- ki: Knock-in allele
- wt: Unmodified loci (wild type)
- x / y: Can be used instead of wt to clarify inheritance patterns for X- and Y-linked modifications
- ?: Used where the genotyping protocol cannot distinguish homozygous from hemi-/heterozygous
Avoid plus and minus: You must never use + or -, as these are easily misunderstood.
Examples of Simple Genotypes
ko/ko
tg/?
fl/wt
Multiple Genetic Modifications
If the animal has two genetic modifications, the following applies:
- Both modifications must appear in the strain name.
- The genotypes must be separated by a semicolon ; between the allele pairs.
Example: ko/ko;tg/x
Special Rules for the Barrier Unit
The Barrier Unit protects and secures unique strain lines. To allow staff to operate the unit efficiently, the following routines apply:
- Cage setup: Staff will maintain up to two breeding cages for each genetic modification, as well as two reserve cages with animals of defined genotypes.
- Transfer of animals: As soon as at least one of the breeding cages produces offspring, all remaining cages are transferred to the MDU.
- Hold request: If you wish to keep a litter for future breeding, you must request that the specific litter remain in the barrier pending genotyping.
Do you require deviations from these conventions? Contact the KM staff to arrange a meeting.
Contact and Tools
Responsible unit: Comparative Medicine
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