At first glance, humans and cats are incredibly different. No one would ever get the two confused. However, it may not surprise too many cat lovers to learn that cats and humans are more alike than they appear. As the cat genome has been mapped out and studied, there is more and more evidence that we are more like our kitties than we ever knew.

Title Photo Credit: OneSharp via Flickr

What is a genome?

Figure 1

Human chromosomes
Photo Credit: Libertas Academica via Flickr

Simply put, a genome is all of the genetic information contained within a cell. This is the information that controls all of the physical characteristics that a living organism will have; it is what makes a cat have cat characteristics and a human have human characteristics.  The genome is made up of several thread-like structures called chromosomes. Chromosomes are tightly packaged bundles of genetic information; Each bundle contains a different piece of the creature’s physical make up.

The genetic information within the chromosomes is broken further into genes and DNA. DNA is a long strand of bonded amino acids in a very specific order. It is famously shaped like a double-helix. Genes are segments of DNA that give the directions for creating specific proteins. We inherit genes from our parents that come together to create our physical traits. Segments of DNA that are between genes can turn the genes on or off.

Cats Versus Humans

Cinco and Robin Selfie

Me (human) + Cinco (cat) = Love!

Scientists have long been working on mapping out the genomes of living creatures. Mapping out the human genome was not complete until April of 2003. It has been found that cats and  humans are 90% genetically similar. That is a higher percentage of similarity than humans with dogs (82%), cows, mice, or rats. It seems that the only animal more similar to humans is the chimpanzee at 98% similarity.

To take a look at just one piece of the cat genome, a study done in 1999 compared the X and Y chromosomes of cats to those of humans. These chromosomes are known for creating the male and female characteristics in mammals. All mammals have these chromosomes and they all contain the same genes. However, in most mammals, these genes are in a different order than they are in humans. In cats, the X chromosome is an exact match to humans and there is only 1 gene out of order on the Y chromosome. At the time the study was completed, there had never been another mammal tested that had more similar X and Y chromosomes to humans than cats.

How the Cat Genome Can Help Humans

There is a method to the madness of putting the cat genome in order. Scientists believe that the cat genome could change the medical world for the better. There are more than 250 hereditary illnesses in cats that have a human equivalent. Figuring out how these diseases work in cats could hold the keys to solving them for humans as well. Some of the illnesses scientists believe cats could help to solve include:

  • Cancer (several types)
  • Male infertility
  • Heart disease
  • AIDS
  • Hemophilia
  • Polycystic Kidney Disease
  • Diabetes
  • Liver disease

For those that love a good mystery – the cat genome also provides an interesting addition to forensic science. Now that they know how to sequence cat DNA, it is possible to do DNA testing on cats reliably. Should cat hair be found at the scene of a murder, it can be matched to the murder’s cat. This evidence is solid enough to be used in court too.

Do you think that  your cat looks or acts like you?

Sources & Digging Deeper 

Initial sequence and comparative analysis of the cat genome -Genome Research

Why does your cat love you…sort of? DNA unravels feline mysteries – Genetic Literacy Project

Cats and humans share similiar X and Y chromosomes – Genome News Network

Feline Genome Research Advances – The Scientist