How House Finches Get Their Red Feathers

House finches are known for their vibrant red feathers. These feathers are a result of a specific pigment called 3-hydroxy-echinenone. This pigment is a type of carotenoid. Carotenoids are colorful compounds found in many plants and animals. They are responsible for the bright colors in many birds' feathers. Scientists have long believed that all birds with red feathers use the same process to create this pigment. This process involves two key enzymes: CYP2J19 and BDH1L. However, recent studies on house finches have challenged this belief. Researchers wanted to see if house finches use these same enzymes to produce their red feathers. They looked at the function of these enzymes in house finches and tracked their activity during feather growth. The results were surprising. It turns out that CYP2J19 and BDH1L do not play a role in creating the red pigment in house finches. Instead, these birds likely use a different set of enzymes to produce their red feathers.The study also found that these enzymes are not very active in the liver or feather follicles of house finches. These are the areas where pigment production is thought to occur. Additionally, the enzymes are found in a different part of the cell than where the red pigment is concentrated. This further suggests that house finches use an alternative pathway to create their red feathers. So, what does this mean? It means that the process of creating red feathers in birds is more complex than previously thought. Different species of birds may use different methods to achieve the same vibrant red color. This discovery opens up new avenues for research into the evolution of bird coloration. It also highlights the importance of studying multiple species to understand biological diversity.