Gene expression in mature pollen and sperm cells versus young seedling as a vegetative sporophyte reference control

Sperm cells represent the male partner that fuses with the egg cell during fertilization in all multi-cellular eukaryotic organisms, and, in flowering plants, is a founder of both embryo and nutritive endosperm. We examined the transcriptome of Oryza sativa ssp. japonica using the Affymetrix 57K rice genome GeneChip to provide an overview of genes activated in the paternal gamete. We used microarrays to detail the global program of gene expression in mature pollen and sperm cells at anthesis, which constitutes the stage immediately preceding pollen germination and gamete deposition leading up to fertilization. This documents the condition of the male gametophytic cells prior to fertilization. Keywords: tissue expression profile, male gametophyte, sperm, pollen, seedling Male gametophytic cells consisting of isolated pollen and isolated sperm cells collected at anthesis were compared with seedlings containing leaf, stem, root and apical meristems as a vegetative sporophytic control; three separate biological replicates were used.