Genomic profiling of rice sperm cell transcripts reveals conserved and distinct elements in the flowering plant male germ lineage

• Published in: The New phytologist 2012-08, Vol.195 (3), p.560-573
• Main Authors: Russell, Scott D., Gou, Xiaoping, Wong, Chui E., Wang, Xinkun, Yuan, Tong, Wei, Xiaoping, Bhalla, Prem L., Singh, Mohan B.
• Format: Article
• Language: English
• Subjects: angiosperm sperm cells; Animal embryos; Biological fertilization; Cell fusion; Cell Survival; Chromatin; Chromatin - genetics; chromatin modeling; Divergence; DNA microarrays; Embryos; Endosperm; Epigenesis, Genetic; Epigenetics; expression profiling; Fertilization; Flowering; Flowering plants; gamete transcriptome; Gametes; Gene expression; Gene Expression Profiling - methods; Gene Expression Regulation, Plant; Gene sequencing; Gene silencing; Genes; Genes, Plant; Genomes; Genomics; Germ cells; Germ Cells, Plant - cytology; Germ Cells, Plant - metabolism; Histones; male gamete expression; male germ unit; Males; Oligonucleotide Array Sequence Analysis - methods; Oryza - cytology; Oryza sativa; Plant Cells - metabolism; Plant diseases; Plants; Pollen; Reproduction; Ribonucleic acid; Rice; RNA; RNA Interference; RNA, Plant - genetics; RNA-mediated interference; Seedlings; Seedlings - genetics; Seedlings - metabolism; Somatic cells; Sperm; Spermatozoa; Transcriptional Activation; Ubiquitin
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2012.04199.x

Genomic assay of sperm cell RNA provides insight into functional control, modes of regulation, and contributions of male gametes to double fertilization. Sperm cells of rice (Oryza sativa) were isolated from field-grown, disease-free plants and RNA was processed for use with the full-genome Affymetrix microarray. Comparison with Gene Expression Omnibus (GEO) reference arrays confirmed expressionally distinct gene profiles. A total of 10 732 distinct gene sequences were detected in sperm cells, of which 1668 were not expressed in pollen or seedlings. Pathways enriched in male germ cells included ubiquitin-mediated pathways, pathways involved in chromatin modeling including histones, histone modification and nonhistone epigenetic modification, and pathways related to RNAi and gene silencing. Genome-wide expression patterns in angiosperm sperm cells indicate common and divergent themes in the male germline that appear to be largely self-regulating through highly up-regulated chromatin modification pathways. A core of highly conserved genes appear common to all sperm cells, but evidence is still emerging that another class of genes have diverged in expression between monocots and dicots since their divergence. Sperm cell transcripts present at fusion may be transmitted through plasmogamy during double fertilization to effect immediate post-fertilization expression of early embryo and (or) endosperm development.