Is There a Genetic Basis for the Unique Behaviors of Siamese Cats?

siamese-cats

Guest post by Ingrid R. Niesman, MS PhD

The dark horse wins the race”. “Our hero strides forth on a shiny white steed”. Humans have long been mystified over animal behaviors and coloration. Albinos have been alternatively feared or revered. Black cats summon up dark arts imagery. But is there really a connection between a cat’s fur and their behavior or is this just superstition? My research is aimed at unraveling at least a small part of this enduring mystery.

Is there a connection between coat color and behavior?

Previous research published in 2015* seems to suggest that owners report more aggressive behaviors from orange female (tortoiseshells, calicos, and “torbies”), black-and-white, and gray-and-white cats cats at home and during vet visits. But statistical analysis and included data from vet visits finds no differences in aggressive behavior due to coat color. In rodents, however, scientists have found that agouti mice display increased stress-induced weight loss and exhibit symptoms of acute fearfulness following stress caused by physical restraints compared to normal mice.** My personal interest in the connection between looks and behavior stems from my long co-habitation with generations of Siamese cats.

My love of Siamese cats

I love Siamese cats. My family had two as we grew up. I adopted my first female right out of college and she became my constant companion and source of joy. She did have a strange habit of eating wool hiking socks and sweaters. It wasn’t until I adopted one of my two current boys that this behavior rose to more than an amusement. Eating non-foods is a syndrome called pica. Within the Siamese breed, there has been considerable documentation and some scientific reports on this unusual habit.

My kitten ate two pipe-cleaners, then a large elastic bow that required emergency surgery. He can destroy the toughest dog chewies in a matter of hours. As a scientist, this piqued my curiosity. Why Siamese and Siamese-derived breeds? Could there be a genetic link, like the overexpressed agouti gene in mice, altering normal behavior?

x-ray-cat-foreign-body

The science behind skin coloration

Skin coloration is a highly conserved mechanism throughout the animal kingdom. Humans tan in response to UV light. The darkening is caused by production of melanin. Lack of an ability to generate skin melanin results in albinos- all light or all white animals. One key protein that is required to create melanin is called tyrosinase. When the genetic code for a normal protein is changed, something scientists term mutated, the way a protein folds into its unique shape is disrupted. This can cause the protein to malfunction. For Siamese cats, the tyrosinase gene has a single altered amino acid about half way into the protein. This small change has a profound effect on the action of this protein. Siamese tyrosinase only functions below normal feline temperatures, which creates the beautiful color-pointed appearance we associate with our lovely furbabies.

Skin color and behavior

Now, let’s tie this all together. What does a mutated tyrosinase gene have to do with Siamese behavior? Besides the well-described role in melanin production, tyrosinase is very good at multi-tasking. In certain brain cells, tyrosinase is also a key protein in the generation of the neurotransmitter, dopamine. Areas of either human or feline brains that use dopamine are associated with anxiety and obsessive compulsive disorders when this neurotransmitter’s levels are imbalanced.

In a Siamese cat, dopamine-requiring neurons will have to rely on an alternative backup pathway. Under ideal feline conditions, a Siamese can maintain a balanced amount of dopamine using the backup pathway. However, when these cats are stressed, either chronically, as in a shelter environment, or acutely, as in a vet visit, their neurons may be incapable of increasing dopamine to compensate for the added stress.

My current research is revolving around modeling the Siamese-specific tyrosinase mutation in cells to figure out three important findings. The first, what is the actual molecular basis for tyrosinase to work at lower temperatures, but not at normal cat temperatures. Two, does the mutated tyrosinase protein fold into a normal shape. And three, do Siamese cat neurons have normal or reduced levels of dopamine in neurons following stress.

Goals of my research

My long-term goal is to find either potential drug interventions to keep Siamese cats calmer and more social in shelters to increase their adoptability, or work with feline behaviorists to use my information to devise modifications to keep dopamine levels high in Siamese when stress is likely. The bonus for me personally is saving money on expensive chew toys.

I am currently self-funding my studies since the idea of Feline Cell Biology is outside of the mainstream scientific community’s thinking. Look for future posts on my progress.

If you’d like to help me and ultimately help all of us further understand all feline behavior at a molecular level, please like and share this post across your social networks.

Ingrid R. Niesman MS PhD is the Director of the SDSU Electron Microscope Imaging Facility at San Diego State University.

* Elizabeth A. Stelow, Melissa J. Bain & Philip H. Kass (2016) The Relationship Between Coat Color and Aggressive Behaviors in the Domestic Cat, Journal of Applied Animal Welfare Science, 19:1, 1-15, DOI: 10.1080/10888705.2015.1081820

** Ruth B.S. Harris, Jun Zhou, Mingxia Shi, Steven Redmann, Jr., Randall L. Mynatt, Donna H. Ryan (2001) Overexpression of agouti protein and stress responsiveness in mice, Physiol & Behavior, 73;4, 599-608, DOI: doi.org/10.1016/S0031-9384(01)00508-X

9 Comments on Is There a Genetic Basis for the Unique Behaviors of Siamese Cats?

  1. Steve Mann
    May 26, 2019 at 1:58 pm (3 weeks ago)

    We currently have a siamese cat awaiting adoption at APS of Durham (this was as of 5/24/19. Questions or help adopting? You may contact me at 720-838-6117, Steve Mann, cat leadership team member.

    Reply
  2. Eleanor Skibo
    May 22, 2019 at 8:39 pm (4 weeks ago)

    Many moons ago I owned a Siamese female cat. Samantha was gorgeous in her coloring and her blue eyes were so piercing they appeared to stare right through you. Samantha’s personality was unique beyond belief; she would talk with bugs and if they were high up they’d fall to the ground and she’d digest them. Samantha would chatter on an on to whoever or whatever she thought was listening. And she just loved to jump through the center of my upper floor railings right into my lap, unexpectedly of course scaring the wits out of me. She also was absolutely in love with my male Maltese and she would prod him to chase, leading him to a bedroom underneath the bed. She slid underneath, but Max always got stuck yipping and yelping for help. Siamese cats are very unique.

    Reply
  3. Kim
    May 22, 2019 at 4:38 pm (4 weeks ago)

    This is really interesting. I wonder what her findings will be…

    Reply
    • Ramona
      May 22, 2019 at 6:20 pm (4 weeks ago)

      Fascinating! Since the Siamese is a foundation breed does this mean the particular genes may be inherited?

      Reply
  4. Suzanne
    May 22, 2019 at 9:50 am (4 weeks ago)

    Has a wonderful female siamese named Bon Noel that I got as kitten and had for 18 years; my son, who was in nursery school at the time named her after he learned to say Bon Noel in a Christmas pageant at his school. She was a wonderful companion to my son throughout the years, have great photos of her sitting at the table with group of his young friends celebrating his birthday, riding on his shoulder, always very much his best friend.
    However, she too was very fond of eating wool; ate the collar point of a wool shirt, took bite out of the hemline of a wool coat. I learned to be very creative in redesign of clothing and also to hang up clothing and shut closet doors tightly! She also ate the corner off of my sons birthday cake that was going to his class to help celebrate, that too required a quick patch-up before I left for work and delivering my son and his cake to school.

    She was the only kitten in the litter that didn’t have a bobbed tail but had a tail with a hook on the end that frequently became caught on lamp cords pulling lamps off the table among other things. She loved to climb drapes, jumped on the back of a repairman scaring him half to death, managed to fall into a coal bin in our cellar; many funny and memorable situations over the years that continue to bring a smile to my face.

    Reply
  5. Janine
    May 22, 2019 at 7:37 am (4 weeks ago)

    I found this very interesting. I have never been owned by a Siamese cat, but I have heard of their unique personalities and traits.

    Reply
  6. Stoney Truett
    May 22, 2019 at 7:10 am (4 weeks ago)

    We have two Siamese in our home group, a brother and sister who were abandoned at our feral colony. The male is more social and able to integrate into mail group but the female stays in my office because she seems to be a pariah and is chased to the point of hiding under our couch unless I rescue her and take her to her sanctum. Her brother will spend time with her from time to time if he gets stressed. We have observed characteristics related to different cats based on coat color and have been fascinated that cats of similar color characteristics behave in similar fashions. I would love to discuss this with you or someone involved with your project and participate if we may.
    You may contact me at 803-603-1140 or stoneytruett54@gl.com

    Reply
    • Ingrid Niesman
      May 23, 2019 at 2:42 pm (4 weeks ago)

      Dear Ramona
      The mutated tyrosinase gene is the signature piece of DNA that defines the Siamese phenotype. To be a “color-pointed” Siamese, a cat must have the mutation on both sets of chromosomes – termed homozygous. This gene is also recessive, which means if a cat has a normal gene and a mutated one, the normal gene function masks the mutated one.
      So, short answer, yes to be a Siamese the cat must have inherited the temperature sensitive mutant from both parents.
      Thank you for this insightful question.
      Ingrid Niesman PhD

      Reply
    • Ingrid
      May 23, 2019 at 2:58 pm (4 weeks ago)

      Dear Stoney
      Thank you for providing this story for me. I am looking for these kinds of details from “citizen scientists” to help me refine my basic theory. I am particularly interested in learning from owners of aging Siamese about their experiences with aged behaviours. However, I would appreciate data, even observational data, on specific behaviors and coat colorations. If you can track each feline’s weekly activities, the amount of perceived stress during the week and provide breed or coat color information that would be helpful. By activities, I generally mean sleep patterns, eating rituals, social interactions with your household pets, litter use and human interactions. This is not a scientific survey, but can be the basis for scientific proposals in the future. Good and interesting science is a result of human observations, followed by sound and solid scientific experimentation. I could be very wrong about my hypothesis, but until we test it; we will never know.
      Ingrid Niesman PhD

      Reply

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