Pigment

Pigment

Since all sheep are either black or brown there has to be 2 mechanisms for coloring sheep.

  • The black mechanism is through the production of the pigment eumelanin. This occurs when the melanocyte’s (pigment producing cell) receptor for the alpha melanocyte stimulating hormone are open and available for the cell and hormone to connect.
  • The brown/ tan mechanism is through the production of pheomelanin. This occurs when the melanocyte’s (pigment producing cell) receptor for the alpha melanocyte stimulating hormone are blocked.

This still doesn’t explain the ranges of tan. The amount of pheomelanin can explain this. A lot of pheomelanin is dark brown a small amount of pheomelanin is pale tan. Red falls in this spectrum more toward the darker side but can reach up to upper end.

One thought on “Pigment

  1. The amount of tan can be explained by rufus modifiers. For example, say red is + and not red is -. A sheep that is ——–++ is not very red, but one that is —-++++++ is much more red. This is quite universal in many mammals. Rabbits are a good example.

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