Biology 1001A Lecture Notes - Lecture 12: Melanosome, Melanin, Melanocyte
16 Nov 2012
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The allele for black colour must be dominant to the allele for brown colour. Answer: some would be black and some would be brown in mendel"s 3:1 ratio. Skin and hair pigments are created in specialized cells called melanocytes. Two kinds of melanin can be made, one in each colour. To melanin is shipped in melanosomes to the skin cells, resulting in the pigmentation of the skin and hair. When mc1r is on , cyclic amp (camp) levels in the cell are high and the melanocyte produces. The black allele is insensitive to hormone control and camp is always high. When both of these alleles are together, Pig cell has both receptors functioning at the same time. It doesn"t matter what the brow allele is doing because the black allele keeps the black melanin level high at all times. The black allele never interferes with the brown allele in any way.
