Encyclopedia of Cat Chromosomes, Diseases and Traits

When you receive your cat’s DNA report, you will see a Chromosome Map, which shows your cat’s chromosome pairs with regions of genomic similarity to different breed groups shown in different colors. Many pet parents in the Basepaws community expressed an interest in learning more about what genes reside on each cat chromosome. Here, we share all that is currently known about feline chromosomes and genes associated with hereditary conditions and traits.

DNA and chromosomes

The DNA in cell nuclei is tightly packaged for its storage and protection. This packaging is done with the help of proteins (histones), forming a structure called chromatin. Chromatin is the reason why meters-long DNA can fit inside tiny cells only a few micrometers in diameter. It is a dynamic structure and it is very important for regulating which genes get switched on and off in different cells at different times. A great metaphor for chromatin gene regulation is that genes are like important files stored in a file cabinet. The cabinet’s drawers are always opening and closing and the different files are constantly being pulled out and copied, then returned to their original location.

Inside the cell, chromatin folds into structures called chromosomes. Each chromosome contains a single string of DNA. However, it is important to note that chromosomes should not be thought of as standalone functional units. Genes responsible for similar cellular processes and organismal traits are scattered across different chromosomes. Therefore, it would be inaccurate to say that a particular chromosome is (solely) responsible for eye color, for example.

Cats have 1 pair of sex chromosomes and 18 pairs of autosomal (non-sex) chromosomes (Figure 1). In each chromosome pair, there is one chromosome that comes from the mother and one chromosome that comes from the father. Interestingly, cats and humans share greater chromosomal organization similarity than humans and rodents and cats and rodents. This means that, in a lot of cases, genes found next to each other in human chromosomes are also found next to each other in feline chromosomes.

Figure 1. Graphical representations of each chromosome and trypsin Giemsa-banded staining of the chromosome pairs in domestic cats (Felis catus). Chromosome names follow the convention of Wurster-Hill and Gray (image taken from O’Brien and Nash, 1982).

Feline genes and chromosomes

Although feline genetics is in a much less advanced state than human genetics, years of research have given us some idea of what feline genes are located on each chromosome. Below is a summary of what we know so far.



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