Project description:Maize anthers ranging in size from 0.5mm to 3.0mm in increments of 0.25mm were dissected and their cells isolated using the FX-Cell protocol. scRNA-seq libraries were prepped using the CEL-Seq2 protocol and sequenced with 150bp PE reads with Illumina HiSeq or NovoSeq. The developmental trajectories of the somatic cell layers were investigated.
Project description:In flowering plants, anther dehiscence and pollen release are essential for sexual reproduction. Anthers dehisce after cell wall degradation weakens stomium cell junctions in each anther locule, and desiccation creates mechanical forces that open the locules. Either effect or both together may break stomium cell junctions. The microRNA miR167 negatively regulates ARF6 and ARF8, which encode Auxin Response transcription Factors. Arabidopsis mARF6 or mARF8 plants with mutated miR167 target sites have defective anther dehiscence and ovule development. Null mir167a mutations recapitulated mARF6 and mARF8 anther and ovule phenotypes, indicating that MIR167a is the main miR167 precursor gene that delimits ARF6 and ARF8 expression in these organs. Anthers of mir167a or mARF6/8 plants overexpressed genes encoding cell wall loosening functions associated with cell expansion, and grew too large starting at flower stage 11. Experimental desiccation enabled dehiscence of miR167-deficient anthers, indicating competence to dehisce. Conversely, high humidity conditions delayed anther dehiscence in wild-type flowers. These results support a model in which miR167-mediated anther growth arrest permits anther dehiscence. Without miR167 regulation, excess anther growth delays dehiscence by prolonging desiccation.
Project description:Transcriptomes from multiple pre-meiotic stages of wild type, mac1, and msca1 maize anthers were characterized by microarray hybridization. The goal was to characterize the developmental progression as the anther specifies five cell types and grows rapidly precedeing meiotic entry. The stages characterized were immature anther primordia (0.15 mm long in maize) containing just stem cells, through somatic and germinal cell fate specification (0.20 and 0.25 mm), mitotic proliferation (0.4 mm), and finally the birth of the middle layer and tapetum (0.7 mm). To obtain cell-type specific markers, at 0.7 mm we also compared whole anthers to collections of laser-microdissected anther cell types including the archesporial cells (pre-meiotic germinal cells), nutritive layers (middle layer and tapetum) and structural layers (endothecium and epidemis) of the anther lobe. keyword: anther development, maize, male-sterile
Project description:The lifelong replenishment of blood cells relies on the function of definitive HSCs that migrate to the bone marrow during development. This process is tightly controlled by the bone marrow microenvironment. Embryonic macrophages emerge before the onset of definitive hematopoiesis, seed into discrete tissues and contribute to specialized resident macrophages throughout life. However, the functional impact of embryonic macrophages on HSCs or the niche remains unknown. Here, by taking advantage of a lineage tracer mouse tool we show that bone marrow macrophages consist of two ontogenetically distinct cell populations from embryonic and adult hematopoiesis. Mice lacking embryonic myeloid cells have decreased HSC numbers in the bone marrow accompanied by an increase of stem cells in the liver of neonate mice. The emergence of HSCs from embryonic sources is unperturbed because pre-HSC and HSC numbers are normal, suggesting a key role for embryo-derived myeloid cells in orchestrating HSC trafficking around birth. We show here that the establishment of a normal cellular niche space in the bone marrow critically depends on embryonic myeloid cells that are important for the development of mesenchymal stromal cells, but not other non-hematopoietic niche cells, providing evidence for a specific role for embryo-derived myeloid cells in the establishment of a normal niche environment pivotal for HSC homing.
Project description:The lifelong replenishment of blood cells relies on the function of definitive HSCs that migrate to the bone marrow during development. This process is tightly controlled by the bone marrow microenvironment. Embryonic macrophages emerge before the onset of definitive hematopoiesis, seed into discrete tissues and contribute to specialized resident macrophages throughout life. However, the functional impact of embryonic macrophages on HSCs or the niche remains unknown. Here, by taking advantage of a lineage tracer mouse tool we show that bone marrow macrophages consist of two ontogenetically distinct cell populations from embryonic and adult hematopoiesis. Mice lacking embryonic myeloid cells have decreased HSC numbers in the bone marrow accompanied by an increase of stem cells in the liver of neonate mice. The emergence of HSCs from embryonic sources is unperturbed because pre-HSC and HSC numbers are normal, suggesting a key role for embryo-derived myeloid cells in orchestrating HSC trafficking around birth. We show here that the establishment of a normal cellular niche space in the bone marrow critically depends on embryonic myeloid cells that are important for the development of mesenchymal stromal cells, but not other non-hematopoietic niche cells, providing evidence for a specific role for embryo-derived myeloid cells in the establishment of a normal niche environment pivotal for HSC homing.
Project description:Global gene expression profiles of seven stages representing 29 days of anther development are analyzed using a 44K oligonucleotide array querying ~80% of maize protein-coding genes. Each anther stage expresses ~10,000 constitutive and ~10,000 or more transcripts restricted to one or a few stages. Keywords: anther development, maize
Project description:Wheat, an important human food crop, is very sensitive to temperature changes. Thermosensitive sterile lines (TMS) is a natural material for exploring the effects of anther development and temperature changes on male fertility. In order to study the possible molecular mechanism of regulating protein activity during anther fertility alteration, proteomics analysis based on high resolution mass spectrometry were used to study the binuclear anther of wheat YS3038.
Project description:We describe here a new micro-proteomics workflow for the analysis of individual barley anthers. The workflow detects more than 4000 proteins from small amounts of material representing single or paired anther samples, covering a dynamic range of protein expression levels across five orders of magnitude. We consistently identified ~2800 proteins in a single 0.6mm anther and ~4000 proteins in a paired-anther sample. This demonstrates an important technological advance in plant proteomics, considering the limited amount of starting material. We employed our micro-proteomics workflow to investigate the proteome of the developing barley anther containing male gametes in the early stages of meiosis. We successfully identified several low abundant meiosis-related proteins, proving that our approach is highly sensitive and consequently powerful. To date, no work has been published previously on precisely staged individual plant anthers.