| Functional |
"These two genes (ABCG5 and ABCG8) encode the half transporters sterolin-1 and sterolin-2. Sterolins have a dual role in sterol excretion, and are expressed at the brush border membrane of enterocytes and the canalicularmembrane of hepatocytes (76,77)." |
10.1093/nargab/lqz012 |
| Timing of Loss |
"Several gene-inactivating mutations are shared between the African and Asian elephant, indicating that ABCG5 and ABCG8 were already lost in the ancestor of both elephant species." |
10.1093/nargab/lqz012 |
| Phenotypic |
"Similarly, a double knockout of ABCG5 and ABCG8 in mouse results in substantially increased plasma phytosterol levels (79). Given that loss of ABCG5 and ABCG8 reduces cholesterol synthesis in both human and mouse (79,80), it is possible that the loss of these genes could be beneficial for
strictly herbivorous elephants and manatees by saving energy necessary to synthesize cholesterol, which occurs only in small amounts in an herbivorous diet." |
10.1093/nargab/lqz012 |