Project description:Transcriptional profiling in young flowers (stage 8) of Arabidopsis wild type control plants and sdg2-1 mutant is performed using Aligent’s Whole Arabidopsis Gene Expression Microarray (G2519F, V4, 4x44K). A significant number of genes involved in gametophyte development are found differentially regulated in the sdg2-1 mutant.
Project description:Small RNA diversity and function has been widely characterized in various tissues of the sporophytic generation of the angiosperm model Arabidopsis thaliana. In contrast, there is limited knowledge about small RNA diversity and their roles in developing male gametophytes. We thus carried out small RNA sequencing on RNA isolated from four stages of developing Arabidopsis thaliana pollen. Spores from 4 stages of pollen development (UNM: Uninucleate microspore M-bM-^@M-^S BCP: Bicellular pollen M-bM-^@M-^S TCP: Tricellular pollen M-bM-^@M-^S MP: Mature pollen) were isolated using a percoll gradient-based method (Honys and Twell, 2004) and the small RNA fraction for each sample was isolated and sequenced by Illumina technology. Reference: Honys, D. and Twell, D. (2004) Transcriptome analysis of haploid male gametophyte development in Arabidopsis. Genome Biol. 5/11/R85.
Project description:Pollen is the male gametophyte of land plants. Proper development and maturation of pollen is necessary for the successful reproduction of seed plants. This process involves sophisticated coordination between sporophytic and gametophytic tissues in anthers. To advance the mechanistic studies of anther development, additional players need to be discovered for a comprehensive understanding of the underlying regulatory network. Here we show that the Arabidopsis dual specificity tyrosine phophorylated and regulated kinase (DRYK), AtYAK1, is essential for development of rosette leaves and the male but not female gametophyte in Arabidopsis. Arabidopsis mutant plants carrying a mutation in AtYAK1 produce developmentally stalled microspores, likely because of the defects in the two consecutive mitosis steps in the post-meiotic maturation process of pollen. The mutation of AtYAK1 has a significant effect on gene expression programs in developing pollen. Transcritpome analysis of atyak1 revealed downstream genes in families of protein kinases, transporters and transcription factors, which potentially contribute to pollen development. This study represents the first molecular characterization of DYRK in the plant kingdom. Our results also imply that the regulation of cytokinesis by DYRKs is evolutionally conserved in fungus, fruit fly, animals and plants.
Project description:Transcriptional profiling in young flowers (stage 8) of Arabidopsis wild type control plants and sdg2-1 mutant is performed using Aligentâs Whole Arabidopsis Gene Expression Microarray (G2519F, V4, 4x44K). A significant number of genes involved in gametophyte development are found differentially regulated in the sdg2-1 mutant. Two-condition experiment, young flowers of wild type control vs. young flowers of sdg2-1 mutant. Two biological replicates: 2 control, 2 mutant, independently grown and harvested. One replicate per array.
Project description:How plants first invented seeds is a longstanding unresolved evolutionary question. Seed-bearing plants arose from within seedless vascular plants, with ferns as their closest relatives, but how seed development originated from ancestral reproductive development has remained unresolved by comparative morphology or the fossil record. To investigate this question at the level of gene network evolution, we identified genes associated with reproduction across sporophyte and gametophyte reproductive development of the fern Ceratopteris richardii and tested their conservation with reproductive gene networks in Arabidopsis thaliana. The flowering signal gibberellin was conserved with the fern shoot sporing transition and sporophyte sporophyll genes were conserved with floral development but not seeds. Post-fertilization gametophyte archegonium genes demonstrated significant conservation with both pre- and post-fertilization seed gene networks, together with two experimentally validated post-fertilization mechanisms. We conclude that the seed may first have arisen through the mis-expression of archegonium developmental programmes within the developing sporophyte sporangium.