Day 11 has 54 protein-coding genes, including one named after a god: BRDT (bromodomain, testis-specific.) Bromodomain proteins are special because they can recognize a chemical modification of proteins (acetylation of lysines) that is often used in gene regulation. Enzymes with bromodomains can use them to turn genes on and off by taking acetyl groups on and off of the tails of the histone proteins that the genome is wrapped and packed around.
The bromodomain is not named after the element bromine, but rather after the brahma gene of the fly Drosophila melanogaster, where it was discovered as a gene regulator in 1988. Other regulators discovered in the same genetic screen were also named after deciders of fate, such as urdur, sallimus, and moira.
Because BRDT is only expressed in sperm, it has been considered an attractive male contraceptive target.
The bromodomain is conserved in organisms as distant as yeast, meaning it is at least a billion years old.