Scientists have determined how the leopard gets its spots

From leopard spots to tiger stripes, cat fur is one of the most recognizable in the animal kingdom. Now researchers at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama, USA, have identified the gene behind these patterns. Their findings were published in the journal Nature Communications.

Cats of all sizes are born with the same coat pattern and color for life. And, the scientists found, a signaling molecule encoded by the Dkk4 gene is responsible for this embellishment. Differences in the expression of the molecule while the embryo is still developing lead to a variety of patterns that emerge during later coat growth.

The evolution and beauty process of wild and domestic cats has long interested scientists and now scientists, determined to find out when these patterns first begin to develop, have found that it occurs while the embryo is still developing. Previous studies have shown that color patterns in domestic cats appear when groups of neighboring hair follicles produce different types of pigments. However, the developmental process that determines whether a hair follicle produces black or yellow melanin remains unclear.

Scientists explain that the biology of the development of self-organizing color patterns in mammals remains an unsolved mystery. Complex color patterns are a defining aspect of morphological diversity in cats, but they are difficult to study because there is no real counterpart in model organisms.

A new study has shown that early in development, banding changes appeared in the thickness of the skin, preceded by a preliminary pattern of gene expression. The secreted Wnt inhibitor encoded by Dickkopf 4 plays a central role in this process. According to scientists, the genes that control simple color variations, such as albinism or melanism, are mostly the same in all mammals, and now the biology underlying mammalian color pattern, which had long been a mystery, has also become clear.