UW researchers have identified a gene linked to the productivity
of stem cells that produce sperm in mammals. The group, whose
findings appear in the June issue of Nature Genetics, was led by
Robert Braun, associate professor of genome sciences. In adult
organisms, germ stem cells, which produce sperm, can either
produce more germ stem cells or produce daughter cells that
eventually become sperm cells. Producing more germ stem cells
helps keep sperm production going over the long term. Braun and
his colleagues identified a decades-old strain of mice they
believed had a genetic mutation that caused their germ stem
cells to be more likely to convert to sperm than to produce more
germ stem cells and keep the cycle going. They obtained 30-year-
old frozen embryos of the mouse strain from the Jackson
Laboratory in Maine and conducted genetic tests to confirm the
theory. Researchers located the mutation on a gene called
ZPF145, which produces the protein PLZF. They used a fluorescent
antibody against the protein to