(1) A kind of maternal-effect gene (as in nanos gene) whose function is to code for products used for establishing the normal patterning of posterior abdominal segments of certain embryos (e.g. Drosophila).
(2) The transcription product of nanos gene, attaching to the cytoskeleton and concentrating at the posterior section of the egg.
In fruitfly embryo, the nanos gene is important in the formation of the more posterior abdominal segments. A defect in this gene results in an embryo with defective abdominal segmentation.
See also: maternal-effect gene.