Gay markers

The link of male homosexuality to
q28 gene on the X chromosome was
recently reinforced by scientists,
exactly 2 years after the first evidence in its favour was produced.
After studying a sample of 33 pairs
of homosexual brothers, a team led
by Stacey Cherny in USA has now
reported conclusively that a majority of gays share this gene. However,
its presence has been found to be
negligible in 36 pairs of lesbian sisters studied by the scientists
(Science, Vol 268, No 5217).

Meanwhile, a study on 5,000
same-sex twins, conducted by
Australian researchers established
that for males, homosexuality is 50
per cent heritable while for females
the figure is considerably low.