Day 8 has 40 protein-coding genes, including LEPR (the leptin receptor.) This gene encodes the protein in the brain that senses leptin, a hormone released by fat cells. Although in general leptin is referred to as the “satiety hormone,” the relationship between leptin and satiety is more complex.
Mutations in the LEPR gene are associated with obesity, in both mice (above) and humans.
The LEPR gene is found in species as distant as fish, meaning it originated at least 440 million years ago.
Click here to see your LEPR gene.