By Nicholas Wade
From The New York Times
The first words ever spoken, so fable holds, were a palindrome and an introduction: ''Madam, I'm Adam.''
A few years ago palindromes -- phrases that read the same backward as forward -- turned out to be an essential protective feature of Adam's Y, the male-determining chromosome that all living men have inherited from a single individual who lived some 60,000 years ago. Each man carries a Y from his father and an X chromosome from his mother. Women have two X chromosomes, one from each parent.
The new twist in the story is the discovery that the palindrome system has a simple weakness, one that explains a wide range of sex anomalies from feminization to sex reversal similar to Turner's syndrome, the condition of women who carry only one X chromosome.
The palindromes were discovered in 2003 when the Y chromosome's sequence of bases, represented by the familiar letters G, C, T and A, was first worked out by David C. Page of the Whitehead Institute in Cambridge, Mass., and colleagues at the DNA sequencing center at Washington University School of Medicine in St. Louis.
The full article is available in the library's LexisNexis database.
