Archives for June 20, 2018

Why is a Dam’s Sample Needed for Parentage Testing?

Why is a Dam’s Sample Needed for Parentage Testing?
Example for marker “A”: Pup is 1,3, Mother is 1,1 and Father is 2,3. The pup inherited allele 1 from the mother and allele 3 from the father.

At Paw Print Genetics, we are often asked this question: “Why do I need to send in a sample on the dam if I just want to know the father of my pups?”. The simple answer is because we need to compare the DNA of the pup to both parents in order to confidently confirm or exclude a potential sire.  Here is an example that helps explain why we need both parents for parentage testing. Keep in mind that a pup receives half of its DNA from its mom and half of its DNA from its dad, so for every marker that we examine, the pup has one allele (gene copy) from mom and one allele (gene copy) from dad.

For parentage (paternity) testing, we use a set of 99 informative markers to confirm or exclude a potential sire. For each marker, we get two results because the pup has two sets of DNA, one from the mom and one from the dad. The two alleles are each assigned a number based on their DNA sequence.  For example, for marker “A”, the pup might be 1,3; one allele has sequence 1 and the other allele has ...