Chromosomes

Whenever a couple of curious kids play a behind-the-woodshed game of doctor, they discover that male and female bodies are different. Later, they learn that nature designed masculine and feminine organs for particular functions, although the specifics can be confusing even for adults. Roseanne Barr says husbands think a uterus is a tracking device.

Scientists have found genetic evidence for what some men have long suspected: It is dangerous to make assumptions about women. The key is the X chromosome, the feminine sex chromosome that all men and women have in common.

Scientists have completed the final analysis of two more human chromosomes. Chromosome 19 with nearly 1,500 genes, including some linked to high cholesterol and insulin-resistant diabetes, is the most gene-dense of those sequenced.

In scientific circles, the Y chromosome -- the essence of masculinity -- is scorned as the runt of the human genetic family, so henpecked by mutations that it is wasting away.

British scientists have mapped chromosome 20, the third and longest chromosome to be sequenced in the Human Genome Project. Chromosome 20 is best known for harboring genes that contribute to forms of the brain-wasting Creutzfeldt-Jakob disease and severe-combined immunodeficiency, an illness in which the immune system is crippled.

This column is dedicated to Smuckers and Chainsaw, two neighborhood cats who strut the local streets flaunting their orange, black and white calico pelts.

North Carolina researchers have identified a short region of chromosome 13--one of the 23 pairs of chromosomes that make up the human genetic blueprint--that contains a gene linked to autism.

Japanese scientists said Friday they had built an artificial chromosome, which might aid efforts to use gene therapy to treat diseases such as muscular dystrophy and cystic fibrosis.