this is from a friend of mine who works at the Bronx Zoo hospital
Skin from an Oustalet's Chameleon
Beneath the epidermis, there are three layers of pigmented cells. The uppermost (outer) layer is composed of the xanthophores which are responsible for yellow and red colors. This is the palest staining layer on H&E. The middle layer is composed of the iridophores (sometimes referred to as guanophores). These cells contain tiny particles that scatter light and result in the blue color perceived by our eyes. Lastly, there is the melanophore layer, which is the deepest layer. These cells have prominent dendritic branches that contain black pigment granules. The melanin granules can be redistributed within the cell, thus affecting how much we can see of the pigment from the xanthophores and the scattered light of the iridophores. The result = the perception of color change (although the color was always there - just masked by the melanin).
Skin from an Oustalet's Chameleon Beneath the epidermis, there are three layers of pigmented cells. The uppermost (outer) layer is composed of the xanthophores which are responsible for yellow and red colors. This is the palest staining layer on H&E. The middle layer is composed of the iridophores (sometimes referred to as guanophores). These cells contain tiny particles that scatter light and result in the blue color perceived by our eyes. Lastly, there is the melanophore layer, which is the deepest layer. These cells have prominent dendritic branches that contain black pigment granules. The melanin granules can be redistributed within the cell, thus affecting how much we can see of the pigment from the xanthophores and the scattered light of the iridophores. The result = the perception of color change (although the color was always there - just masked by the melanin)
Skin from an Oustalet's Chameleon
Beneath the epidermis, there are three layers of pigmented cells. The uppermost (outer) layer is composed of the xanthophores which are responsible for yellow and red colors. This is the palest staining layer on H&E. The middle layer is composed of the iridophores (sometimes referred to as guanophores). These cells contain tiny particles that scatter light and result in the blue color perceived by our eyes. Lastly, there is the melanophore layer, which is the deepest layer. These cells have prominent dendritic branches that contain black pigment granules. The melanin granules can be redistributed within the cell, thus affecting how much we can see of the pigment from the xanthophores and the scattered light of the iridophores. The result = the perception of color change (although the color was always there - just masked by the melanin).
Skin from an Oustalet's Chameleon Beneath the epidermis, there are three layers of pigmented cells. The uppermost (outer) layer is composed of the xanthophores which are responsible for yellow and red colors. This is the palest staining layer on H&E. The middle layer is composed of the iridophores (sometimes referred to as guanophores). These cells contain tiny particles that scatter light and result in the blue color perceived by our eyes. Lastly, there is the melanophore layer, which is the deepest layer. These cells have prominent dendritic branches that contain black pigment granules. The melanin granules can be redistributed within the cell, thus affecting how much we can see of the pigment from the xanthophores and the scattered light of the iridophores. The result = the perception of color change (although the color was always there - just masked by the melanin)
