Project description:Immunologic response of two patient categories, birch pollen allergic and non-allergic, to natural pollen exposure (spring vs. winter) quantitated at the level of the transcriptome
Project description:Fertile pollen is critical for the survival, fitness and dispersal of flowering plants, and directly contributes to crop productivity. Extensive mutational screening studies have been carried out to dissect the genetic regulatory network determining pollen fertility, but we still lack fundamental knowledge about whether and how pollen fertility is controlled in natural populations. We used a genome-wide association study (GWAS) to show that ZmGEN1A and ZmMSH7, two DNA repair-related genes, confer natural variation in maize pollen fertility. Mutants defective in both genes exhibited abnormalities in meiotic or post-meiotic DNA repair, leading to reduced pollen fertility. More importantly, ZmMSH7 underwent selection during maize domestication, and its disruption resulted in a substantial increase in grain yield and protein content for both inbred and hybrid. Overall, our study describes the first systematic examination of natural genetic effects on pollen fertility in plants, providing valuable genetic resources for optimizing male fertility. Moreover, ZmMSH7 may be a potential candidate for simultaneous improvement of grain yield and quality.
Project description:We isolated tricellular pollen (TCP) and pollen mother cells (PMC) of rice using laser microdissection, and did microarray analysis with Agilent 44k rice array.
Project description:Growth plate chondrocytes were isolated from the distal metacarpus of young dairy cattle (all under 10 mo of age), the chondrocytes were released from the extracellular matrix by digestion with Collagenase P for 4 hours, and the various zones of the growth plate were separated by density centrifugation. The least-dense Hypertrophic Zone (HZ) cells were compared to the most-dense Reserve Zone (RZ) cells. 6 pairs of HZ vs RZ were compared by microarray. Experiment Overall Design: Growth plate chondrocytes were isolated from the distal metacarpus of young dairy cattle (all under 10 mo of age), the chondrocytes were released from the extracellular matrix by digestion with Collagenase P for 4 hours, and the various zones of the growth plate were separated by density centrifugation. The least-dense Hypertrophic Zone (HZ) cells were compared to the most-dense Reserve Zone (RZ) cells. Six independent sample pairs of HZ vs RZ were compared by microarray.
Project description:Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. We used a surgical procedure to obtain large quantities of uncontaminated pollen tubes that grew through the pistil and defined their transcriptome by microarray analysis. We also characterized the transcriptome of in vitro-grown pollen tubes (for 0.5hours or 4hours) and dessicated mature pollen in Arabidopsis.
Project description:The number of pollen grains is a critical determinant of reproductive success in seed plants and varies among species and individuals. However, in contrast with many mutant-screening studies relevant to anther and pollen development, the natural genetic basis for variations in pollen number remains largely unexplored. To address this issue, we carried out a genome-wide association study in modern maize, ultimately revealing that a large variance of the absence or presence of sequences in the promoter region of Zea mays RPN1 (ZmRPN1) alters its expression level and thereby contributes to pollen number variation. Molecular analyses showed that ZmRPN1 interacts with ZmMSP1, an ortholog of the male germline cell number regulator in Arabidopsis and rice, and facilitates ZmMSP1 localization to the plasma membrane. Importantly, ZmRPN1 dysfunction resulted in a substantial increase in pollen number, consequently boosting seed production by increasing female-male planting ratio. Together, our findings uncover a key gene controlling pollen number, and therefore modulation of ZmRPN1 expression could be efficiently used to develop elite pollinators for modern hybrid maize breeding.
Project description:<p>Bee pollen is consumed for its nutritional and pharmacological benefits, but it also contains hazardous allergens which has not been identified. Here, we identified 2 potential allergens, glutaredoxin and oleosin-B2, in <em>Brassica napus</em> (<em>B. napus</em>) bee pollen using mass spectrometry-based proteomics analyses, and used bioinformatics to predict their antigenic epitopes. Comparison of fermented (by <em>Saccharomyces cerevisiae</em>) and unfermented bee pollen samples indicated that glutaredoxin and oleosin-B2 contents were significantly decreased following fermentation, while the contents of their major constituent oligopeptides and amino acids were significantly increased based on metabolomics analyses. Immunoblot analysis indicated that the IgE-binding affinity with extracted bee pollen proteins was also significantly decreased after fermentation, suggesting a reduction in the allergenicity of fermented bee pollen. Furthermore, fermentation apparently promoted the biosynthesis of L-valine, L-isoleucine, L-tryptophan and L-phenylalanine, as well as their precursors or intermediates. Thus, fermentation could potentially alleviate allergenicity, while also positively affecting nutritional properties of <em>B. napus</em> bee pollen. Our findings might provide a scientific foundation for improving the safety of bee pollen products to facilitate its wider application.</p>