SEARCH GOES ON FOR `GAY GENE'

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, March 14, 1993                   TAG: 9303140243
SECTION: HORIZON                    PAGE: D-1   EDITION: METRO 
SOURCE: 
DATELINE: BY JEFF NESMITH COX NEWS SERVICE                                LENGTH: Medium
SEARCH GOES ON FOR `GAY GENE'
The issue of whether people become homosexuals because of "nature or nurture" is one of the most controversial subjects scientists have confronted in recent years.
Several teams of geneticists are searching for a "gay gene" with the encouragement of homosexual organizations, who hope it will refute the charge that lesbians and gay men choose to become homosexuals.
Such a finding would undermine some critics' claims that homosexuality is immoral.
Until the middle 1980s, the prevailing view among most scientists was that homosexual "tendencies" were mostly the result of upbringing. Dominant mothers, unloving fathers, a failure to resolve the Oedipus complex and effeminate role models were viewed as most likely causes.
In the mid-1980s, researchers at Boston University found that the brothers of gay men were five times more likely to be gay than the brothers of heterosexuals. Although this could mean nothing - since brothers might share upbringing experiences - it revived interest in the possibility that genetic factors were responsible.
Studies by Dr. Fred Whitam of Arizona State University and others found that identical twins of homosexuals are more likely to be homosexual than men who have fraternal twins who are homosexual. Later, researchers at the Salk Institute in San Diego found anatomical differences between homosexual and heterosexual men in parts of the brain noted for differences between men and women.
Theories gravitate to the role of male sex hormones. Male rats that are given carefully timed injections to block the release of male sex hormones in developing fetuses go on to become normal adults - except that they try to mate with other males.
The search for a "gay gene" may be fruitless, some geneticists believe, because the homosexuality could turn out to be "polygenic," the result of a combination of many genetic factors, each playing a small role. The overall mix could vary from individual to individual.
By looking for "marker" genes, Dr. Dean Hamer of the National Institutes of Health, is searching for what he suspects will be a small cluster of responsible genes, perhaps associated with the production of sex hormone.

by Archana Subramaniam by CNB