noun, plural: maternal genes
(1) A gene from the mother's genome in which its expression on the phenotype of the zygote is determined from the mother's genotype, not from the zygote's.
(2) A gene from the maternal genome whose products are required for the early development of the embryo, such as the establishment of the overall polarity of the embryo.
Maternal genes are required for the normal development of the embryo. They produce transcription products that establish the polarity, even before fertilization takes place. These genes also determine the basic body plan of the embryo. In Drosophila embryogenesis, examples of maternal genes are bicoid, nanos and caudal.
Also called: maternal-effect gene.
Compare: paternal gene, zygotic gene.