Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA.
Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
Sci Rep. 2017 Jun 19;7(1):3838. doi: 10.1038/s41598-017-03878-4.
The maize endosperm consists of three major compartmentalized cell types: the starchy endosperm (SE), the basal endosperm transfer cell layer (BETL), and the aleurone cell layer (AL). Differential genetic programs are activated in each cell type to construct functionally and structurally distinct cells. To compare gene expression patterns involved in maize endosperm cell differentiation, we isolated transcripts from cryo-dissected endosperm specimens enriched with BETL, AL, or SE at 8, 12, and 16 days after pollination (DAP). We performed transcriptome profiling of coding and long noncoding transcripts in the three cell types during differentiation and identified clusters of the transcripts exhibiting spatio-temporal specificities. Our analysis uncovered that the BETL at 12 DAP undergoes the most dynamic transcriptional regulation for both coding and long noncoding transcripts. In addition, our transcriptome analysis revealed spatio-temporal regulatory networks of transcription factors, imprinted genes, and loci marked with histone H3 trimethylated at lysine 27. Our study suggests that various regulatory mechanisms contribute to the genetic networks specific to the functions and structures of the cell types of the endosperm.
淀粉胚乳（SE）、基底胚乳转移细胞层（BETL）和糊粉层细胞层（AL）。在每种细胞类型中激活不同的遗传程序，以构建具有不同功能和结构的细胞。为了比较参与玉米胚乳细胞分化的基因表达模式，我们从授粉后 8、12 和 16 天（DAP）时富含 BETL、AL 或 SE 的冷冻分离胚乳标本中分离出转录本。我们对分化过程中三种细胞类型中的编码和长非编码转录本进行了转录组谱分析，并鉴定出具有时空特异性的转录本簇。我们的分析表明，12 DAP 的 BETL 经历了编码和长非编码转录本最动态的转录调控。此外，我们的转录组分析还揭示了转录因子、印迹基因和组蛋白 H3 赖氨酸 27 三甲基化标记的基因座的时空调控网络。我们的研究表明，各种调节机制有助于形成与胚乳细胞类型的功能和结构特异性相关的遗传网络。
