Research suggests distinctive piebald patterns on cats, horses and mice are
caused by cells dividing too slowly in the womb
Cats with black and white patches have their distinctive colouring determined in the womb, according to new research Photo: Steve Parsons
Black and white cats get their distinctive colouring because of the way their cells develop in the womb, research suggests.
Scientists said cats with a two-tone coat do not have enough pigment cells because the cells divide too slowly.
The research also found that cells move randomly rather than following
instructions, so in animals without enough pigment cells, colour is
distributed in random patches.
Scientists
hope the research could help shed light on medical conditions that also
occur because of cell development in an embryo Photo: ALAMY
The findings could aid understanding of medical conditions such as holes in the heart, which can also be caused by cells not moving to the right place as an embryo develops.
The black and white pattern, known as piebald, can also be seen in some horses. Researchers at the Universities of Bath and Edinburgh carried out their study on mice and believe they have debunked the previous assumption that the unusual colouring is caused by slow-moving cells.
Piebald patterns form because of the way pigment cells move and multipy randomly in early development Photo: Adam Gray / SWNS.COMProfessor Ian Jackson of the University of Edinburgh said: “The black and white cat has a mutation and it was assumed that because we knew those cells moved through the skin, it was because the cells didn’t move fast enough, but what we have shown is actually the cells move faster in the black and white cat or spotted mice.
“The problem is there’s not enough of them so they don’t divide enough, they divide more slowly.
“It was always imagined that there would be a signal that would tell them where to go, but they just move at random.
“It’s like diffusion - if you put a drop of milk in a cup of coffee that milk spreads through the whole cup of coffee. Eventually the cells spread through the skin.”
Some horses also have a piebald pattern Photo: ALAMY However, when there are not enough of the pigment cells, they do not reach all areas of the skin, resulting in the distinctive patchy black and white patterns.
The mathematical model used by the scientists could now be used for further research tracking different cells during early development.
“The fact that they move randomly means there can be a random element in developments processes,” Professor Jackson said.
“If you have got enough cells then that random process doesn’t really matter because there’s enough cells to go around to do the job but if you have a mutation and there aren’t enough cells sometimes they will get there and sometimes they won’t, so there’s a random element.”
The way pigment cells are distributed to make cats black and white could also help our understanding of some medical conditions
Dr Christian Yates a Mathematical Biologist from the University of Bath, said the findings were “counter intuitive”.
“Previously it was thought that the defective kit gene slowed cells down but instead we’ve shown that it actually reduces the rate at which they multiply.
“There are too few pigment cells to populate the whole of the skin and so the animal gets a white belly.
“In addition to kit, there are many other genes that can create piebald patterns, the mathematical model can explain piebald patterns regardless of the genes involved.’’
The research is published in Nature Communications.
source
