BACKGROUND: In plants, pollination is a critical step in reproduction. During pollination, constant communication between male pollen and the female stigma is required for pollen adhesion, germination, and tube growth. The detailed mechanisms of stigma-mediated reproductive processes, however, remain largely unknown. Maize (Zea mays L.), one of the world's most important crops, has been extensively used as a model species to study molecular mechanisms of pollen and stigma interaction. A comprehe ...[more]
Project description:In this study, we sequenced four small RNA libraries derived from mature pollens, in vitro germinated pollens, mature silks and pollinated silks of maize, respectively. In total, 161 known miRNAs belonging to 27 families and 82 novel miRNAs were identified. Of them, miRNAs involved in pollen-silk (pistil) interactions were analyzed. On the male side, miRNA differentially expressed between mature and germinated pollen were identified, some of them participate in pollen germination and tube growth. On the female side, silk-expressed miRNAs respond to pollination were also responsive to stresses, especially drought and fungal invasion. Furthermore, GO analysis of target genes revealed that members related to anxin signal transduction and gene expressional regulation were overrepresented.The results indicated that during pollen-silk interactions, miRNAs-mediated auxin signal transduction plays important roles, and miRNAs took part in complex transcriptional regulating network. Examination of 4 different tissues of maize to provide novel information for understanding the post-transcriptional regulations of pollen-pistil interactions
Project description:Despite much knowledge is well-known on the transcriptional and enzymological regulation of many genes in starch synthesis, including SBEⅡb, Waxy, and SUS-SH1 genes, less information is available on their expression profiles as a consequence of their dysfunction. Hence, transcriptional adjustments in response to mutations were required for a better understanding of starch biosynthesis pathway, others metabolism and cell response. We used microarrays to detail the transcriptional adjustments in the endosperms of ae wx and sh1 at 15 days after pollination (DAP) compared to B73. Maize endosperms at 15 DAP were selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain homologic endosperms of middle ears in order to increase the temporal resolution of expression profiles.
Project description:In this study, RNA-seq based comparative transcriptome analysis was used to study the genetic response of maize silk to pollen tube penetration and in comparison to the fungal invasion of Fusarium graminearum and Ustilago maydis. RNA-seq libraries of 8 tissues were generated from leaf, root, seed, pollen tube, silk, pollinated silk, infected silk with Fusarium and infected silk with Ustilago.
Project description:According to the physiological change of the ear leaf, the developing ear leaf after pollination can be divided into three classes: mature leaves [ML, 0–14 days after pollination (DAP)]; early senescent leaves (ESL, 15–24 DAP); and later senescent leaves (LSL, 25–30 DAP). We harvested ear leaves at 12 DAP, 20 DAP, and 28 DAP, representing ML, ESL, and LSL, respectively. To identify genes involved in the leaf senescence process, we sequenced three cDNA libraries, ML (12 DAP), ESL (20 DAP), and LSL (28 DAP) using an Illumina HiSeqTM 2000.
Project description:Eukaryotic mRNAs are subject to multiple types of tailing which critically influence mRNA stability and translatability. To investigate RNA tails at the genomic scale, we previously developed TAIL-seq, but its low sensitivity precluded its application to biological materials of minute quantity. In this study, we report a new version of TAILseq (mRNA TAIL-seq or mTAIL-seq) with enhanced sequencing depth for mRNAs (by ~1000 fold compared to the previous version). The improved method allows us to investigate the regulation of poly(A) tail in Drosophila oocytes and embryos. We find that maternal mRNAs are polyadenylated mainly during late oogenesis, prior to fertilization, and that further modulation occurs upon egg activation. Wispy, a noncanonical poly(A) polymerase, adenylates the vast majority of maternal mRNAs with a few intriguing exceptions such as ribosomal protein transcripts. By comparing mTAILseq data with ribosome profiling data, we find a strong coupling between poly(A) tail length and translational efficiency during egg activation. Our data suggest that regulation of poly(A) tail in oocytes shapes the translatomic landscape of embryos, thereby directing the onset of animal development. By virtue of the high sensitivity, low cost, technical robustness, and broad accessibility, mTAIL-seq will be a potent tool to improve our understanding of mRNA tailing in diverse biological systems. Two sets of RNA-seq on 3 developmental stages (immature oocyte, mature oocyte, and activated egg) of wild type and wispy mutant of Drosophila melanogaster.
Project description:We use the gowth zone of the maize leaf as a model system to study the growth reduction in response to drought stress. The spatial gradient and the relatively large size of the maize leaf allowed us to sample at a subzonal rezolution and to examine different developmental stages at the same time. We compared the response to different levels of drought stress (mild and severe) of proliferating (meristem), expanding (elongation zone) and differentiated (mature zone) tissue. Three separate loop designs were used for the three zones of the maize leaf (meristem, elongation zone, and mature zone). In each loop three treatments were contrasted (control, mild stress, and severe stress). Four biological replicates were used for each zone/condition (4 replicates x 3 zones x 3 conditions = 36 samples).
Project description:Spider silk synthesis is an emerging model for the evolution of tissue-specific gene expression and the role of gene duplication in functional novelty, but its potential has not been fully realized. Accordingly, we quantified transcript (mRNA) abundance in seven silk gland types and three non-silk gland tissues for three cobweb-weaving spider species. Evolutionary analyses based on expression levels of thousands of homologous transcripts and phylogenetic reconstruction of 605 gene families demonstrated conservation of expression for each gland type among species. Despite serial homology of all silk glands, the expression profiles of the glue-forming aggregate glands were divergent from fiber-forming glands. Also surprising was our finding that shifts in gene expression among silk gland types were not necessarily coupled with gene duplication, even though silk-specific genes belong to multi-paralog gene families. Our results challenge widely accepted models of tissue specialization and significantly advance efforts to replicate silk-based high-performance biomaterials. Overall design: We isolated mRNA from seven types of silk glands and three non-silk gland tissues for three species of cobweb weaving spiders. We aimed for two replicate isolations of each tissue, but failed to obtain sufficient material for all tissue types for each species. Each replicate RNA isolate included tissue from 8-29 individuals.
Project description:To investigate whether and what miRNAs expression might be regulated by VSV (vesicular stomatitis virus?) challenge, we analyzed the miRNA expression profile of mouse primary peritoneal macrophages infected with VSV by using an array-based miRNA profiling. After the infection of VSV at MOI 10 for 48 h, the array revealed that many miRNAs were up-regulated in macrophages?