Journal of Integrative Plant Biology 2008 GAMETOPHYTIC FACTOR 1, Involved in Pre-mRNA Splicing, Is Essential for Megagametogenesis

RNA biogenesis is essential and vital for accurate expression of genes. It is obvious that cells cannot continue normal metabolismwhenRNA splicing is interfered with. sgt13018 is such amutant, with partial loss of function ofGAMETOPHYTIC FACTOR 1 (GFA1); a gene likely involved in RNA biogenesis in Arabidopsis. The mutant is featured in the phenotype of diminished female gametophyte development at stage FG5 and is associated with the arrest of early embryo development in Arabidopsis. Bioinformatics data showed that homologs of gene GFA1 in yeast and human encode putative U5 snRNP-specific proteins required for pre-mRNA splicing. Furthermore, the result of yeast two-hybrid assay indicated that GFA1 physically interacted with AtBrr2 and AtPrp8, the putative U5 snRNP components, of Arabidopsis. This investigation suggests that GFA1 is involved in mRNA biogenesis through interaction with AtBrr2 and AtPrp8 and functions in megagametogenesis and embryogenesis in plant. Key words: embryogenesis; female gametophyte; pre-mRNA splicing; U5 snRNA complex