July 16, 2001 -- The poet Alexander Pope famously declared that
"the proper study of mankind is man." But just what a man is
depends on the definition you choose. Warrior? Not exclusively a male role
anymore. Leader? Yes, but women are also leaders. Hunter-gatherer? Sorry,
fellas, like the old TV commercial said, women can bring home the bacon
and fry it up in a pan.
So that pretty much leaves biology. Thank goodness we can still
count on the old sex chromosomes, Ms. X and Mr. Y, can't we? Sure, the X
chromosome has nearly 3,000 genes on it, compared with a measly two or three
dozen on the Y chromosome. But you still need a Y to make a guy, right?
Technically, yes, but it seems that even here there's some disagreement.
Dates that end with lovemaking often begin with dining out, so that the meal
itself can be seen as a form of sexual foreplay -- in more ways than one. How
many times has this happened to you: You take your woman out to dinner at a
nice restaurant. The waiter takes your drink orders and tells you of the
specials, a busboy brings you a choice of savory breads, and you get down to
the business of perusing the menu. Your eye is on the right side of the page --
steak? lobster? steak and lobster?...
The Human Genome Project is beginning to reveal some rather
surprising clues into the role the Y chromosome has played over time, and now
there's evidence to suggest that the X chromosome may also play a key role in
the development of sperm. In fact, says Jeremy Wang, PhD, with the Whitehead
Institute for Biomedical Research in Cambridge, Mass., some cases of male
infertility may turn out to be X-chromosome-linked disorders transmitted from
mothers to sons.
"This is like color-blindness, hemophilia -- those are
X-linked disorders; the defect is passed on by the mother. So it's possible
that male infertility could be passed on by the mother. The mother has one
defective gene, the other is on the Y type [contributed by the father's sperm],
and it could be passed on to her son, and her sons are infertile," says
Wang, a postdoctoral fellow in the laboratory of David Page, MD, professor of
Biology at the Massachusetts Institute of Technology and investigator at the
Howard Hughes Medical Institute at the Whitehead, which is affiliated with
Page and colleagues have been playing gene detective, tracing
through the 300-million-year history of the Y chromosome in search of clues to
the mysteries of maleness, reproduction, and infertility, and what they found
is enough to turn inside out the conventional thinking about gender and the
contributions of mother and father.