`Perfect husband' gene discovered

SCIENTISTS HAVE discovered a genetic basis for monogamy and believe the findings could shed light on the brain chemistry of love and attachment.

By transferring a single gene, the researchers have been able to convert naturally polygamous males with anti- social tendencies into paragons of fidelity and sociability.

Although the research was performed on mice and voles, they believe the conclusions have important repercussions for the study of human relationships, especially those that break down because of mental illness.

Tom Insel and Larry Young, neuroscientists from Emory University in Atlanta, Georgia, transferred a gene from the sociable, monogamous male prairie vole into male mice, which are promiscuous and aggressive.

The gene is responsible for making a protein in the brain that acts like the "lock" for a key neurotransmitter called vasopressin, which is known to be implicated in determining sociability and monogamy in rodents. Without the protein lock, the vasopressin key cannot exert its effect on the brain.

The two scientists have shown in a study published in the journal Nature that male mice genetically engineered with the vole gene exhibit a dramatic change in behaviour, becoming more content with a single sexual partner and less aggressive towards other males.

"The transgenic mice really surprised us... these mice responded to vasopressin just like prairie voles," Dr Young said.

The two scientists say they intend to study the role of vasopressin in people because virtually every form of human psychiatric disorder is characterised by abnormal social attachments. "Discovery of such information could be clinically relevant for treatment of autism, schizophrenia, Tourette's syndrome and Alzheimer's disease, all of which result in isolation and detachment," they say.