Wednesday, October 19, 2005

Gay Gene

THE AUTHOR of the following article is a good friend of mine who, despite being heterosexual and now happily raising a family in Japan, is sensitive to gay issues, although on a scientific point of view.

Terence Talorete (Butch Talo to his friends) holds a doctorate in animal cell biology from the University of Tsukuba (where he graduated valedictorian and was awarded the best in dissertation), in Japan, and a Master of Science in Microbiology from the University of the Philippines Diliman (where he was awarded the most outstanding graduate), in Quezon City. He finished his BS in Biology, magna cum laude, at the University of St. La Salle, in Bacolod City, Central Philippines.


Is homosexuality a social aberration or a product of nature’s unpredictable and, sometimes, malicious quirks?


A LADY friend of mine had married an openly gay man, despite some misgiving by her family and friends whether their marriage would work out.

For a few years the husband tried to act like a straight male and be a role-model to their two young boys. But after a while, he reverted to his old self and even beat up his wife. They separated after only five years of marriage.

Surprisingly, their first-born showed signs of femininity since he was two years old. Now in high school, the boy is very effeminate and gay. The second son, however, is straight.

Such a case will have contributed to the raging debates as to whether homosexuality is a genetic trait, akin to one born with blue eyes or brown hair.

Despite the scientific advances made to settle the issue, the results continue to remain ambivalent, as empirical evidences still point to various causes: genes, environment, and even the theory of past lives.

Attributing a genetic basis to homosexuality is a double-edged sword. If there is such a thing as a "gay gene," then members of the so-called "third sex" could not be faulted for being who they are.

Society, then, would have an obligation to cater to their basic personal and social needs, like allowing same-sex marriages and legal adoption.

This presupposes, however, that the society they are in is democratic and free.

But in such countries as Saudi Arabia, where homosexual practices are punishable by death, and given the present advances in amniocentesis (the process of drawing amniotic fluid out of the uterus which is then analyzed to detect abnormalities in, or determine the sex of, the fetus) and genetic screening, unborn babies with the gay gene may not see the light of day.

Homosexuality then becomes a "disease" that requires "treatment."

In Romania, the Caribbean and Malaysia, where homosexuals have been persecuted for just being themselves, coming out of the closet equals moving into jail. Having the gay gene becomes a lifelong stigma.

Let us look at recent research trends that aim to settle the issue.

A landmark paper published in the journal Science, in 1993, first posited the gay gene concept.

Using pedigree and linkage analysis on 114 families of homosexual men, Dean H. Hamer and his colleagues from the US National Institutes of Health concluded that same-sex orientation was found in the maternal uncles and male cousins of these subjects, but not in their fathers or paternal relatives, suggesting the possibility of sex-linked transmission in a portion of the population.

They believed that the gay gene was found in the X chromosome that all men inherit from their mothers. (All human beings have 46 chromosomes in their cells, including the sex chromosomes X and Y. Men are 46,XY, while women are 46,XX.)

Two years later, in 1995, the same research group confirmed their findings in the journal Nature Genetics, by extending their analysis on the role of the X chromosome in sexual orientation by DNA (the molecule that controls all cellular functions, including reproduction) linkage analyses of two newly ascertained series of families that contained either two gay brothers or two lesbian sisters, as well as heterosexual siblings.

The results again showed that male homosexuality was linked to the X chromosome.

Surprisingly, however, this was not true for lesbians. Possibly, a different gene carried lesbianism, they said.

That didn’t end there. Six years later, in April, 1999, scientists from the University of Western Ontario, led by George Rice, questioned the gay gene data.

In a paper published in the journal Science, they disputed Hamer’s work with new results showing that there was no link between homosexuality and the X chromosome.

Hamer reacted by saying that the way the Ontario researchers selected their subjects tended to hide the X chromosome contribution. He pointed out that what he had said was that the gene did not influence all cases of male homosexuality but only those that were transmitted maternally.

And in contrast to his group, the Ontario team did not select families based on the presence of maternal transmission.

Way back in 1991, psychologist Michael Bailey of Northwestern University, in Illinois, found out that fully 52 per cent of the identical twins of gay men were also gay, compared to just 22 per cent for fraternal twins.

Yes, genes may contribute to homosexuality in males but some scientists believe that researchers should look instead elsewhere in the X chromosome.

For one, genetic linkages for other complex traits such as manic depression and schizophrenia had fallen apart under closer scrutiny.

While homosexuality does run in certain families, the search for the elusive gay gene--if ever there really is one--continues.

There are some cases, however, where genes play a clearer role.

A study was reported in the journal Biological Psychiatry, in which a 21-year-old female with depression and suicidal thoughts admitted her desire to become a boy since childhood. Cytogenetic investigation revealed her chromosome pattern to be 47,XXX. The extra X chromosome clearly caused her gender identity disorder.

(You may have your chromosome pattern checked at the Institute of Human Genetics at the University of the Philippines Manila. Call up 526-1710.)

If homosexuality is strictly gene-based, then why does it persist when this would result in fewer offspring? Can it be caused by parental consanguinity? No, say researchers.

Can birth order or the number of one’s brothers or sisters cause it? No, say some researchers again.

But others believe otherwise.

The birth order effect on homosexuality may be a by-product of a biological mechanism that shifts personalities more in the feminine direction in later born sons, reducing the probability of these sons engaging in unproductive competition with each other.

One study has shown that homosexual-bisexual pedophiles had a later birth order than heterosexual pedophiles (Journal of Abnormal Psychology, 1997).

Other researchers theorize that homosexuality is a polygenetic trait, e.g., governed by a synergistic set of genes. During development, these genes nudge the male brain towards the female direction.

However, inheritance of a smaller number of these genes makes the male more sensitive, tender, kind, better fathers and, consequently, more attractive mates.

Support for this polygenetic theory on homosexuality is strengthened by behavioral similarities in gays and lesbians that are not directly related to sexual orientation.

According to a recent study published last year in the journal Archives of Sexual Behavior, homosexual males and females would awake earlier, go to sleep later, and thus have shorter sleep duration compared to heterosexuals.

In an interesting study to explore possible differences in the speech patterns of gay and straight men, tape recordings of monologue readings from five openly gay men and four straight men were played to 25 listeners for judgments of perceived sexual orientation.

Listeners correctly identified the sexual orientation of these speakers at a rate close to eight per cent, showing that openly gay men demonstrate certain speech characteristics that are discernible to listeners.

In another study published in the American Journal of Epidemiology (March, 2000), homosexually active men are more likely to undergo depression and panic attack syndromes, while homosexually active women are more likely than other women to become alcohol-, drug-, or nicotine-dependent.

Gay, lesbian, bisexual, or "not sure" youth were a bit over three times more likely to attempt suicide, says another study in the Archives of Pediatric and Adolescent Medicine (May, 1999).

Is sexual orientation, therefore, primarily a biological phenomenon?

Researcher W. Byne wrote in the Journal of Homosexuality that the precise contribution of biological factors to the development of sexual orientation remains to be elucidated.

Recent neurostructural and genetic linkage evidence pertaining to sexual orientation must be viewed tentatively until it has been adequately corroborated and integrated with psychological and cultural models, according to Byne.

True enough, genetics and environmental influences, either alone or together, cannot fully explain all the disorders or abnormalities observed in medicine and psychology.

These include phobias and philias observed in early infancy, unusual play in childhood, differences in temperament manifested soon after birth, unusual birthmarks and their correspondence with wounds on a deceased person, unusual birth defects, and differences (physical and behavioral) between monozygotic (derived from a single fertilized ovum, or identical) twins as well as homosexuality and gender identity disorder.

Some researchers believe that the hypothesis of previous lives can contribute to the further understanding of these phenomena.

Now, can my lady friend’s first-born be blamed or ostracized for having homosexual tendencies? Or is he just a "victim" of nature’s unpredictable and, sometimes, malicious quirks?


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