The Study of Human-Animal Interactions The CAIRC Scholarship Program Summary of the Past Researches
Summary of the Past Scholarship Research
From "Letter from CAIRC" July 2003
Research Theme: "Expression of Fur Color Patterns in Cats: Understanding the Formation of Individual Characteristics in Companion Animals"
By Yuko Kubo
doctoral student majoring in the Department of the Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University

Presented by the joint researcher, Hiroaki Yamamoto
Assistant Professor, Graduate School of Life Sciences, Tohoku University
For many years, Ms. Kubo, Yamamoto and their research partner Urara Fukuzaki, have been studying how genetic characteristics manifest themselves in the fur color of common mice. The extension of that research to fur color in cats was a fresh departure for them:

“The purpose of our research is to shed light on the mechanisms by which pigment cells are generated, and how that mechanism has evolved. It is a well established fact that pigment cells help protect against ultraviolet rays, but this is not their only function. We know that their other functions include nuptial coloration, camouflage and that they play a role in the senses of sight and hearing. Melanin pigment is also known to absorb a wide range of chemical agents, and it also functions as a radical scavenger. The genetic products related to these functions have an influence on the metabolism of energy as well as the immune system. We are also focusing attention from a biological perspective on how factors such as stress can bring about changes in the crucial pigment cell system. The fact that any sudden or major changes in pigment cells due to mutation show up immediately in an animal’s coat and can be distinguished at a glance is one of the great advantages of this line of research. Even if these changes occur, the research does not lead the subject to death in most cases.”

The ability to conduct research that does not kill the subject enables us to obtain long-term data that accompanies the aging of the subject. Small animals that are easy to handle, such as mice, therefore have long been used as subjects for research all over the world on fur color and pigment cells.

“Thus far, we have learned from our research that there are only two types of cells that produce pigment cells in mammals. One of these is a neural crest cell that is particular to vertebrates. This is a cell that spreads throughout the body from the dorsal region and then differentiates to determine characteristics such as hair, fur and skin color. More than 100 genes related to this process have been detected, and several dozen among them have been analyzed to the extent that their base sequences are known. Two of these genes have been firmly established as being related to the color yellow. Since it can be expected that a common component of the basic mechanism for hair color formation in mammals is encoded and preserved in this gene, this research experiment was an attempt to find this gene in cats. Hair color is a major expression of individuality in mammals, and we therefore also hoped to produce clues to the relationship between humans and the cats that have coexisted with them as companion animals for such a long time.”