Eva Ellsworth: Encouraging News for the Y Chromosome

The Y chromosome has 78 genes. All but 16 of them encode sperm production. The non-sperm producing genes have counterparts on the X chromosome. Their duplication on the Y may enhance male fertility. Most of the Y’s genetic material has been lost over the past 300 million years. In her March 20 column, "X-celling Over Men," Maureen Dowd wrote that some experts expect the Y to disappear in as little as 100,000 years. She quoted Dr. David Page, a molecular geneticist at the Whitehead Institute for Biomedical Research, as saying "The Y wants to maintain himself, but doesn’t know how. He’s falling apart like the guy who can’t manage to get a doctor’s appointment or can’t clean up the house or apartment unless his wife does it." Page may have changed his opinion since he made that statement.

According to David Brown’s September 5 Washington Post article, "Study Suggests ‘Y’ the Male Chromosome Will Endure," Page’s laboratory recently completed a comparison study of the human Y chromosome with that of chimpanzees. The two species diverged about six million years ago. Page’s theory was that, if the Y were deteriorating, some of the non-sperm producing genes would be lost to one of the species. The chimp Y chromosome had no non-sperm producing genes that weren’t on the human Y. The Y of both species contained all 16 genes, but five of them were inactive in the chimp. Huntington F. Willard of the Institute for Genome Sciences and Policy believes the theory that the Y is deteriorating is still viable and the process is occurring faster in the chimp. No one knows the answer to that question: Losing genes could indicate the chromosome’s potential extinction or it could be a way of trimming down to the essentials, something indicative of fitness and evolution.

Page’s laboratory also discovered that the Y contains duplicate genes for sperm production. If one of the genes is damaged, the Y "can fold over on itself and swap and splice pieces from different sections in much the same way the two members of a chromosomal pair do." Prior to that discovery, it was believed that the Y simply retained the damaged genes when it replicated. This self-repair mechanism demonstrates the Y’s evolutionary fitness.

The March 17 issue of Nature described a study that demonstrated that, in women, up to 25 genes on the second X chromosome, previously believed to be completely inactive, were active. The number of active genes on the second X varied from woman to woman. In "X-celling Over Men," Dowd gleefully crowed, "Research published last week in the journal Nature reveals that women are genetically more complex than scientists ever imagined, while men remain the simple creatures they appear to be." More complicated isn’t necessarily better, (You’ll probably agree if you’ve ever purchased "assembly required" furniture or children’s play equipment). If people were to take a Dowd-like approach to the Y, they could say Page’s recent studies "reveal" that men are genetically lean, resilient and efficient.

I believe the studies of the Y and of the activity of genes on the second X raise further questions. Does the role in reproductive fitness of the Y correspond to that of the active genes of the second X? Maybe the second X is involved in functions such as fertility and lactation. Since all 25 chromosomes found to be active on the second X are not active in all women, do they turn "on" or "off" at various times such as puberty, pregnancy and menopause? If so, men and women may be more or less equivalent in genetic complexity. Creating a genetic competition between the sexes will not enlighten anyone. A more valid conclusion is that men and women are genetically different. No amount of behavior modification or political correctness can make us the same. Vive la difference!

Remember the September 11 Attacks

Four years ago an al Qaida attack brought down the World Trade towers, four airplanes and part of the Pentagon. My thoughts and prayers are with those who lost friends and loved ones in the attacks and ensuing rescue efforts. I feel boundless appreciation for the first responders and others who helped victims. This anniversary date should remind us all that the War On Terror is worth fighting. It should also remind us to be prepared for the worst. Katrina was a warning that we remain unprepared. Additionally, this day of remembrance should be a cue to remain vigilant. A new tape, purportedly from al Qaida, was delivered to ABC News yesterday. It warned of pending attacks against Los Angeles and against Melbourne, Australia. Terrorists are still trying to destroy our civilization and we must keep fighting them.

In Appreciation of Chief Justice William H. Rehnquist

A tireless defender of the Constitution, Chief Justice William H. Rehnquist, worked until his death from thyroid cancer on September 3. He interpreted laws on the basis of original intent and historical context. He was fully aware that the Constitution is not a "living, breathing document" that could be "interpreted" to fulfill the whim of the moment. As the federal government stretched the interpretation of the Interstate Commerce Clause to encroach upon powers retained by the states, Rehnquist resolutely defended states’ rights. While some on the Supreme Court believed in the use of international law to decide US cases, Rehnquist realized that justice in our country is derived from our Constitution. He was a champion of the founding principals of our nation. Our founding fathers would have been pleased with Justice Rehnquist and many of us will miss him.

Encouraging News for the Y Chromosome

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