What is a Parentage Test?

A parentage test is a DNA-based test that will help confirm the potential parents of an individual cat.  Generally, DNA samples are provided from an individual as well as the cats that are the potential sires and queens.  Since an offspring must have 50% of its genes in common with its sire and its queen, genetic markers can be used to exclude which sire or queen is NOT the true parent.  A sire or queen can be shown to be consistent as being a parent with a very high probabilty.  Several genetic markers, generally 10 - 15, constitute a parentage test and this group of markers is referred to as a "Parentage Panel". 

These markers also generate a unique DNA fingerprint for a cat, hence, the data can also can be used for individual identification.  Cats can then be properly identified if lost, stolen, found dead or confiscated.

If laboratories use the same parentage / identification panels, then the information can be used internationally and any cat can be proven to be the cat of interest, even if it has been shipped anywhere in the world.  Horse registeries have been using DNA testing for many years to confirm the accuracy of the pedigrees and the stud books. 

Parentage and ID tests can be performed with DNA from buccal swabs, hence can be collected by the owner and shipped to any laboratory in the world.  With permission from the owner, the extra DNA remaining after the test can be stored in a "DNA Bank".  These banked samples could later be used upon the owners' request to retest a cat, perform another parentage test, or do a different test at a later time, such as coat colors or disease tests.  The banked samples could also be used in research to help develop new tests if the owner provides permission and additional information, such as color and health information. Parentage tests and ID tests will not identify unknown or known health concerns in the cats!

Many laboratories throughout the world may offer the cat parentage / ID testing.  This test has no patent and has been freely distributed.  Please review information on how to select a good testing laboratory.

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Acknowledgements

Years of preliminary research has led to the development of a worldwide standardized parentage / identification panel for the domestic cat.  Work initiated with genetic testing in the Havana Brown cat breed in order to determine the genetic diversity of the breed.  Hence, we greatly appreciate the assistance of the Havana Brown breeders for getting the ball rolling with genetic testing.  The Havana Brown research was supported by the Winn Feline Foundation.  The Havana Brown project expanded to examine a variety of breeds for genetic diversity.  We appreciate all the breeders who have provided samples over the many years, cat show managers, supporting clubs, and all the individuals who have promoted the work. 

Genetics

Breeds

tThe markers selected for the panel have been tested in a variety of breeds and should be powerful for parentage testing and identification within all breeds and for cats worldwide.

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Background

A standardized genetic marker panel has not been previously developed and implemented for the domestic cat for parentage and identification applications.  The genetics laboratory of Leslie Lyons at the School of Veterinary Medicine, University of California, Davis has a strong research interest in domestic cats, particularly identification of genes for inherited diseases.  As all research pedigrees need to be parentage verified prior to analyses, the Lyons' laboratory has routinely used a panel of publicly available feline derived microsatellites to verify pedigrees and to verify the recently cloned cats.  In addition, the laboratory has estimated the genetic diversity of approximately 50 markers in foundation cat breeds and random bred populations.  This information was used to select 19 markers that would be tested in a preliminary comparison test for the cat.  Since no official forum for the domestic cat exists under the auspice of the International Society of Animal Genetics (ISAG), the comparison test was conducted as an “unofficial” trial.  As a result of a request to ISAG and acceptance by the membership, future cat comparison tests can be performed in an official context as part of the renamed standing committee, Applied Genetics for companion Animals, formally the Applied Genetics for Dog standing committee.

The Lyons' laboratory acted as both the Duty Lab and the Computer/Data Analysis laboratory for the cat comparison test.  A list of laboratories participating in the dog comparison test was obtained from the UC Davis Veterinary Genetics laboratory in anticipation that laboratories offering dog testing services would have interests in providing the same services for the cat. 

Twenty laboratories agreed to participation and had a worldwide distribution including; Australia, Belgium, Canada, Finland (2), France (2), Germany, Hungary, Ireland, Italy (2), Japan, Korea, The Netherlands, Switzerland, South Africa, USA (3).  Markers for the cat comparison test are presented in Table 1 below.  The markers were selected by the usual standards of high variation (PIC) in all breeds, genomic distribution, easy of scoring, previous use and database availability. 

Comparison Test

Aliquots of primers, protocols and DNA samples were sent to all requesting laboratories in May , 2004.   The cat samples included 3 controls, two of which were supplied as DNA isolated from tissue and additionally 2 buccal swabs. These samples were provided to make direct comparisons of the markers on both types of DNA.  Two buccal swabs each of nine cats that formed an inbred pedigree were provided as a parentage and gender identification test.   Two buccal swabs each were provided on eleven random bred cats to compare allele sizes across laboratories.  Allele sizes were provided to the laboratories prior to the submission of results.  Cat microsatellite markers and trait markers are published, see all references below.

Eleven laboratories reported for the cat comparison test.  One laboratory supplied information on the markers in other cat species, including, cheetah, lion and Black-footed cat.  Results were reviewed at the ISAG meeting in Spetember, 2004, Tokyo, Japan.

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Parentage / ID Core Panel Markers

Ten markers with the lowest error rate were selected as a “core” panel for cat parentage and identification and is presented in Table 1 below.  Exclusions were also sufficiently determined with these markers.  An additional marker still needs to be considered for the X chromosome and AMEL was suggested as the best gender marker as it should have different sizes between the X and Y alleles, as known for other species.  Several of the “core” markers are also useful for testing in lions, cheetahs and Black-footed cats.

Table 1. Genetic markers for a “core” cat parentage / ID panel.

M = tetranucleotide repeat
* = one of the originally ten published microsatellites
_ = X-linked marker that needs to be replaced.

Marker F124 was not distributed for the comparison test or tested in the Lyons’ laboratory.

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Points to consider for future comparison tests.

Multiplexing of the core markers should be established and will likely be accomplished by the UC Davis VGL.  Laboratories may want to consider the use of the allele sizing and genotyping software developed at the UC Davis VGL, termed STRand, which is free for distribution.  Nomenclature was suggested as a conversion to “letter” values.  Nomenclature based on repeat size, use of standard cell lines as controls, and sequencing of mid-range and frequent alleles is suggested. 

Many coat color and disease traits are being established for the cat including, PKD, Siamese, Burmese, albino, brown, agouti.  All of these traits are of interest to Persian cats, that generally constitute over 80% of fancy cats worldwide. Agouti is a 3 bp size variation, thus can be easily incorporated into a panel.  

Other markers, such as those used in forensic applications, should be considered for incorporation into future tests and an open invitation exists to suggest potential markers. 

Specific References:

Menotti-Raymond et al., J Forensic Sci. 1997; 6:1039-51.
Menotti-Raymond et al., Genomics. 1999; 1:9-23.
Menotti-Raymond et al., Cytogenet Genome Res. 2003;102: 272-6.
Eizirik et al., Curr Biol. 2003; 13:448-53. (Agouti)
Lyons et al., J Amer Soc Nephrol 2004; 15: 2548-2555. (PKD)
Lyons et al., submitted (Brown)
Lyons et al., submitted (Siamese, Burmese)
Toonen &Hughes. BioTechniques 2001; 31: 1320-1324. (STRand)

 Cat References

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Other useful links:

Veterinary Genetics Laboratory (VGL)

Center for Companion Animal Health (CCAH)

California National Primate Research Center (CNPRC)

Center for Equine Health (CEH)

Department of Population Health & Reproduction (VM:PHR)

Last update: November 30, 2004 This site is under continual development. Please visit again soon! Many of the current pages are the place holders for future information. Please provide suggestions to the webmaster: felinegenome@ucdavis.edu