31.   Neither Mrs. Mahar nor her husband, Daniel, a letter carrier, were aware that they carried the gene for XP when they married.

32.   Ms. Visco also pointed out that the options for women who discover they carry the gene are poor.

33.   On the other hand, surely we are carrying the genes of ancient ancestors who figured out how to spring out of the way of speeding mammoths.

34.   Onyx is also studying ways to use the virus to carry therapeutic genes to tumor cells.

35.   Other studies suggest that the three children have no more than three, four or five individual stem cells that carry the gene.

36.   Plants carrying introduced genes could begin to dominate the population, reducing other traits that offer natural resistance to insects and disease.

37.   Roth is recruiting patients for a second study that would use an adenovirus to carry the gene.

38.   Scientists have used tiny globules of fat to carry genes into damaged brain cells.

39.   Snaking through the nucleolus is a chromosome that carries the genes for making ribosomes.

40.   Some carry a gene that enables them to make a human growth factor in their eggs, while others produce a human antibody.