No, one gene cannot actually control another gene, but one gene can mask the effect of another gene, which is a process called epistasis. For example, a gene in Labrador dogs controls the amount of melanin—in particular the dominant allele B results in large amounts of melanin; a recessive allele b causes less amounts. When bred, a BB or Bb dog is black, while a bb dog is brown. Yet another gene controls whether or not melanin is there at all—the gene E allows for more amounts of melanin while the recessive form e does not. When bred, an ee dog is yellow, while an Ee or EE dog is not yellow and has melanin. Thus, interaction of two genes, the B and E genes, controls coloration in Labrador dogs.