The grain amaranths (Amaranthus sp.) and quinoa (Chenopodium quinoa Willd.) are important seed crops in South America. These crops have gained international attention in recent years for their nutritional quality and tolerance to abiotic stress. We report the identification and development of functional single nucleotide polymorphism (SNP) assays for both amaranth and quinoa. SNPs were identified using a genome reduction protocol and next generation sequencing. SNP assays are based on KASPar genotyping chemistry and were detected using the Fluidigm dynamic array platform. A diversity screen consisting of 41 amaranth accessions showed that the minor allele frequency (MAF) of the amaranth markers ranged from 0.05 to 0.5 with an average MAF of 0.27. A diversity screen of 113 quinoa accessions showed that the MAF of the quinoa markers ranged from 0.02 to 0.5 with an average MAF of 0.28. Linkage mapping in amaranth produced a linkage map consisting of 16 linkage groups, presumably corresponding to each of the 16 amaranth haploid chromosomes. This map spans 1288 cM with an average marker density of 3.1 cM per marker. Linkage mapping in quinoa resulted in a linkage map consisting of 29 linkage groups with 20 large linkage groups, spanning 1,404 cM with a marker density of 3.1 cM per SNP marker. The SNPs identified here represent important genomic tools needed for genetic dissection of agronomically important characteristics and advanced genetic analysis of agronomic traits in amaranth and quinoa. We also describe in detail the scalable and cost effective SNP genotyping method used in this research. This method is based on KBioscience's competitive allele specific PCR amplification of target sequences and endpoint fluorescence genotyping (KASPar) using a FRET capable plate reader or Fluidigm's dynamic array high throughput platform.

With the rapid progress of next-generation sequencing (NGS) technologies, new tools and methods have emerged to investigate the transcriptomics of various organisms. RNA sequencing (RNA-seq) employs NGS to evaluate the presence and abundance of RNA transcripts in biological samples. This technique offers a comprehensive snapshot of the RNA dynamics within cells. With the ability to profile the entire transcriptome of organisms rapidly and accurately, RNA-seq has become the state-of-the-art method for transcriptome profiling, surpassing the traditional microarray approach. Single-cell RNA sequencing (scRNA-seq) was introduced in 2009 to profile the single-cell gene expression in highly heterogeneous samples such as brain tissue and tumors. The advancement of scRNA-seq technologies enables the in-depth transcriptomic study in each cell subtype. When selecting an scRNA-seq method, researchers must weigh the trade-off between profiling more single cells versus obtaining more comprehensive transcripts per cell, while considering the overall costs. The throughput of full-length scRNA-seq methods is usually lower, as each single cell needs to be processed separately to produce scRNA-seq libraries. However, full-length methods enable the researchers to investigate the splicing variants and allele-specific expression. Non-full-length methods only capture the 3' or 5' ends of transcripts, which limits their application in isoform detection, but as cells are pooled after barcoding for cDNA synthesis, the throughput is 2–3 orders of magnitude higher than full-length methods. We developed a droplet-based platform for full-length single-cell RNA-seq, which enabled the efficient recovery of full-length mRNA from individual cells in a high-throughput manner. The developed platform can process ~8,000 single cells within 2 days and detect ~20% more genes compared to Drop-seq. Besides scRNA-seq technology development, we also applied a low-input RNA-seq method to study the transcriptomics in different biological samples. When handling precious biological samples, a low-input method is necessary to profile the transcriptome of homogeneous cell populations. We first studied the epigenomic and transcriptomic regulations in colorectal cancer (CRC) using MOWChIP-seq, a low-input high-throughput method, in conjunction with our low-input RNA-seq approach. Fusobacterium nucleatum (Fnn) is closely related to the progression of cancers like CRC and pancreatic cancer. However, the molecular mechanisms of how Fnn adjusts the tumor microenvironment (TME) and leads to poor clinical outcomes are still unclear. In this in-vitro study, we characterized how hypoxia, an important TME ignored by previous research, facilitates Fnn infection of CRC and corresponding alterations of global epigenome and transcriptome. We infer that hypoxia has similar effects as Fnn infection alone on the CRC cells. The Fnn infection under hypoxia further boosts the proliferation and progression of CRC. We then applied our low-input RNA-seq method to study brain neuroscience and immunology. Psychedelics like DOI show promising clinical efficacy in patients with psychiatric conditions. Although psychedelics exhibit rapid antidepression action and long-lasting effectiveness compared to conventional treatment, their acute psychotic symptoms and potential for drug abuse discourage their application in clinical practice. In this case, it is important to comprehend the molecular mechanisms responsible for psychedelics' clinical efficacy. This understanding can pave the way for the development of improved treatments that do not rely on psychedelics. After profiling the transcriptome of mouse brain samples exposed to psychedelics with different post-exposure times, we concluded that the psychedelic-induced transcriptomic variations are more transient than epigenomic changes. In the second brain neuroscience project, we first applied 3-color FACS sorting to differentiate four neuron and non-neuron subtypes in human postmortem prefrontal cortex tissues. Then we profiled the gene expression of the four subtypes and validated the FACS sorting by examining the expression of marker genes. Differentially expressed genes between each subtype and the others were extracted and proceeded to gene ontology analysis. We identified unique altered biological pathways related to each subtype. The immunology research focuses on revealing the difference between low-grade inflammation and monocyte exhaustion, as well as the unique biological pathways they regulate. Therefore, we profiled the transcriptome of bone marrow-derived monocytes stimulated by PBS control, a low- or high-dose LPS. In addition to wild-type mice, we also included TRAM-deficient and IRAK-M-deficient mice. We concluded that low-dose LPS specifically regulates the TRAM-dependent pathway of TLR4 signaling, and high-dose LPS exclusively upregulates exhaustion markers by impacting metabolic and proliferative pathways. / Doctor of Philosophy / Transcriptomics is the comprehensive study of RNA transcripts derived from an organism's genome. RNA plays a vital role in maintaining the fundamental functions of cells and organisms. In eukaryotes, the genetic information stored in the DNA of cells is transferred to messenger RNA (mRNA) molecules through a process called transcription. These mRNA molecules serve as a bridge between DNA and proteins, as they carry the instructions encoded in genes to ribosomes for protein synthesis. Studying mRNA transcripts reveals various cellular mechanisms and their impact on overall organism function, gene regulation, and disease pathways. With the aid of next-generation sequencing, various RNA-seq approaches have been developed to study mRNA transcripts quantitatively in the past decades. To better understand the gene expression regulations in biological samples, we first applied bulk RNA-seq to profile the transcriptome of various samples under different conditions. Our in-house bulk RNA-seq protocol has been proven to be both high-performance and cost-effective compared to commercial kits. To better understand cellular diversity and uncover rare cell types in heterogeneous biological samples, we developed a droplet-based scRNA-seq platform that can recover full-length mRNA transcripts in a high throughput manner. It can profile the transcriptome of thousands of single cells within two days. It combines the advantages of the droplet-based scRNA-seq method (high throughput) and the well plate-based scRNA-seq method (full-length mRNA recovery).

For over thirty years, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) has been a major contributor to morbidity and mortality in the commercial swine industry across the globe. This highly mutagenic RNA virus causes significant economic losses wherever it is prevalent, leading to $664 million in annual losses in the United States. Unfortunately, the current prevention and diagnostic techniques available have proven to be insufficient in controlling the spread of this disease. We describe an alternative diagnostic method exploiting the rapid turnaround time and long-read capacity of Oxford Nanopore Technology's MinION next-generation sequencer. We have developed a novel primer set designed to span Open Reading Frames 3 through 7 of the PRRSV genome, which has allowed for multiplexing of samples, thus reducing individual cost of testing, while yielding significantly more information than previously available. This novel primer pair and sequencing technique have distinguished mixed infections within individual animals and may be used to determine vaccination status. This new approach will help producers and veterinarians make better-informed decisions about co-mingling of animals and vaccination strategies, thus reducing the emergence of new, pathogenic strains of PRRSV. / Master of Science / Porcine reproductive and respiratory syndrome virus (PRRSV) is a common, economically important pathogen in commercial swine production. The virus was first identified in the late 1980's during outbreaks in the United States and Europe. In female pigs, the disease is characterized by abortion storms, and the delivery of mummified fetuses or very weak, ill piglets. Neonates often display signs of pneumonia, respiratory distress, and many die from hypoxia. Surviving piglets are highly susceptible to other diseases and are poor growers compared to other, unaffected piglets. Boars may show signs of respiratory disease and can also have decreased libido and reproductive success for months at a time. The virus is prone to mutating once a pig is infected, preventing herds from mounting sufficient immunity to protect against new, mutant strains. Identifying infected pigs early and accurately is crucial to managing PRRSV outbreaks. Currently available diagnostic tests for PRRSV have many limitations, thus we have developed a new diagnostic test using next-generation sequencing technology. Oxford Nanopore Technology provides a commercially available nanopore sequencer, the MinION, that can read long DNA strands in real-time. With this technology we have expanded the area of the PRRSV genome that can be sequenced, which allows us to better identify and distinguish strains of PRRSV in infected, and vaccinated pigs. This new testing method will allow veterinarians and practitioners across the country to better identify and predict outbreaks in their herds, helping them develop better management strategies against PRRSV.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第24241号 / 農博第2520号 / 新制||農||1094(附属図書館) / 学位論文||R4||N5412(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 宮川 恒, 教授 三芳 秀人, 教授 森 直樹 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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Previous studies have shown that genes can be switched on or off by age, environmental factors, diseases, and lifestyles. The open or compact structures of chromatin is a crucial factor that affects gene expression. Epigenetics refers to hereditary mechanisms that change gene expression and regulations without changing DNA sequences. Epigenetic modifications, such as DNA methylation, histone modification, and non-coding RNA interaction, play critical roles in cell differentiation and disease processes. The conventional approach requires the use of a few million or more cells as starting material. However, such quantity is not available when samples from patients and small lab animals are examined. Microfluidic technology offers advantages to utilize low-input starting material and for high-throughput. In this thesis, I developed novel microfluidic technologies to study epigenomic regulations, including 1) profiling epigenomic changes associated with LPS-induced murine monocytes for immunotherapy, 2) examining cell-type-specific epigenomic changes associated with BRCA1 mutation in breast tissues for breast cancer treatment, and 3) developing a novel microfluidic oscillatory hybridized ChIRP-seq assay to profile genome-wide lncRNA binding for numerous human diseases. We used 20,000 and 50,000 primary cells to study histone modifications in inflammation and breast cancer of BRCA1 mutation, respectively. In the project of whole-genome lncRNA bindings, our microfluidic ChIRP-seq assay, for the first time, allowed us to probe native lncRNA bindings in mouse tissue samples successfully. The technology is a promising approach for scientists to study lncRNA bindings in primary patients. Our works pave the way for low-input and high-throughput epigenomic profiling for precision medicine development. / Doctor of Philosophy / Traditionally, physicians treat patients with a one-size-fits-all approach, in which disease prevention and treatment are designed for the average person. The one-size-fits-all approach fits many patients, but does not work on some. Precision medicine is launched to improve the low efficiency and diminish side effects, and all of these drawbacks are happening in the traditional approaches. The genomic, transcriptomic, and epigenomic data from patients is a valuable resource for developing precision medicine. Conventional approaches in profiling functional epigenomic regulation use tens to hundreds of millions cells per assay, that is why applications in clinical samples are restricted for several decades. Due to the small volume manipulated in microfluidic devices, microfluidic technology exhibits high efficiency in easy operation, reducing the required number of cells, and improving the sensitivity of assays. In order to examine functional epigenomic regulations, we developed novel microfluidic technologies for applications with the small number of cells. We used 20,000 cells from mice to study the epigenomic changes in monocytes. We also used 50,000 cells from patients and mice to study epigenomic changes associated with BRCA1 mutation in different cell types. We developed a novel microfluidic technology for studying lncRNA bindings. We used 100,000-500,000 cells from cell lines and primary tissues to test several lncRNAs. Traditional approaches require 20-100 million cells per assay, and these cells are infected by virus for over-producing specific lncRNA. However, our technology just needs 100,000 cells (non-over-producing state) to study lncRNA bindings. To the best of our knowledge, this is the first allowed us to study native lncRNA bindings in mouse samples successfully. Our efforts in developing microfluidic technologies and studying epigenomic regulations pave the way for precision medicine development.