What is DNA sequencing?
DNA sequencing is the process of determining the sequence, or order, of the four bases adenine (A), thymine (T), cytosine (C), and guanine (G). The order of bases tells us the kind of genetic instructions that live within a particular segment of DNA. There are many DNA segments in the feline genome, and the specific sequence/order of bases within each segment determines what instructions are given for building and maintaining a cat’s body over time.
DNA sequencing lets us compare the order of bases in different segments of your cat’s DNA to the order of bases of the many segments of DNA that we have in the Basepaws reference genome database (which holds samples of the genomes of cats across 21 pedigree breeds, as well as mixed-breed cats). This allows us to identify your cat’s genomic similarity to other cats in our databases.
Changes can occur in a DNA sequence when it gets copied during the process of DNA replication. These changes are called “mutations” or “variants”. During DNA sequencing, we look for any genetic variants and mark their specific positions in a segment of DNA.
Every cat has a certain set of genetic variants at different locations of the long chains of repeating nucleotides in its DNA. These variants are what differentiate one cat from another cat on the genomic level. For example, in one cat, a segment in a particular location may have a cytosine (C), and in that same location another cat may have guanine (G). The sequencing of your cat’s DNA includes the process of discovering these variants so that we can build your cat’s unique genotype, or collection of genes and genetic variants. The way in which your cat’s genotype is expressed contributes to their expressed observable traits, called the phenotype, such as eye color or coat pattern.
In sequencing the DNA of tens of thousands of cats and comparing them to each other, we’ve been able to see patterns across the genotypes of many cats.
This is what allows us to provide you with your cat’s breed relativity report, which gives you a detailed breakdown of the percentage of the genomic similarity that your cat shares with the 21 pedigree breeds in our reference panel and the four main breed groups to which these breeds belong.
As we sequence more and more DNA samples, these patterns of similarity may change as we identify new variants and their locations across the feline genome, allowing us to refine our data and periodically update Basepaws digital reports.
The field of feline genetics is still quite new, and Basepaws is working to uncover the mysteries of the feline genome by sequencing even the parts of your cat’s DNA that we know nothing about. Our flagship Basepaws Breed + Health DNA test sequences only a small part of the feline genome. That is why we also offer our high-depth Whole Genome Sequencing test as the most comprehensive way to obtain all of the genetic information that lives within your cat’s genome.
If you are interested, you can go into more detail about the Illumina method of DNA sequencing that Basepaws uses. This link provides a step-by-step guide to the process.