Now researchers at Lawrence Berkeley National Laboratory, the University of California at Berkeley, and their collaborators at other institutions have discovered new details of the mechanisms employed by a remarkable animal, the diminutive roundworm Caenorhabditis elegans, to ensure that the chromosomes of its sperm and eggs have been matched and recombined accurately during meiosis. Their discoveries hold promise for understanding human infertility.
Led by Abby Dernburg of Berkeley Lab's Life Sciences Division, who is also an assistant professor of cell and developmental biology at UC Berkeley, the researchers offer new insight into meiosis in C. elegans in two papers published in the 16 December, 2005 issue of Cell, and in a related paper published in the 9 December issue of Science.
C. elegans is a tiny worm less than a millimeter in length and completely transparent. Its reproductive organs make up over half its cells, so by labeling cells with fluorescent dyes and viewing them under a visible-light microscope, observing meiosis is straightforward.
C. elegans has other features that make it particularly useful for studying reproduction. There are two sexes, male and hermaphrodite, with hermaphrodites far more numerous. There are five pairs of nonsex chromosomes and a single sex chromosome, the X. An animal that inherits two Xs becomes a hermaphrodite; a single X chromosome (X0) results in a male.