The male fruit fly makes a song of love with the beat of its wings and a music that is written in its genes.

Now researchers at Brandeis University in Waltham, Mass., say they have found the gene that gives the small insect a love song that is different for each species. Their report was published Friday in the journal Science.Michael Rosbash of Brandeis said Thursday that the mating music gene was proven by experimentally transferring a gene, called the period gene, from two species of singing fruit flies to a mutant fruit fly that is unable to sing properly.

"You can restore its ability to sing in tune by putting this DNA (genetic material) back in," Rosbash said.

The researchers identified the mating song of two fruit fly species, Drosophila melanogaster and Drosophila simulans, by recording the song and then breaking it down into a series of numbers.

They then removed the period gene from each of the singing flies and put them separately into the embryo of the non-singing fruit fly, which is a mutant of the melanogaster.

When the genetically altered fly hatched and matured, it had a rhythm portion of the mating song of donor flies.

"If you use the gene from the other species, then the mutant sings the other species' song," said Rosbash. He said this proves "it is this gene that contains the information for the species-specific song."

The male fruit fly's song is actually a thrumming noise made by its wings."