Project description:Waxy sorghum seeds, defined by reduced amylose content in starch, offer the potential for improving grain quality in food and industrial applications. While waxy endosperms arising from non-functional waxy (wx) allele leading to the absence of Granule-bound starch synthase (GBSS) enzyme have been identified in sorghum, their broader effects on seed development and grain quality remain inadequately understood. To address this gap, we identified a novel wx loss-of-function allele, "wxe" in the mutant population of the sorghum reference genome line BTx623. Beyond reduced amylose content, wxe exhibited increased kernel hardness, elevated protein content, reduced endosperm-to-germ ratio, and decreased kernel weight compared to the wild-type. Integrating transcriptomic, metabolomic, and seed chemistry analyses revealed coordinated regulatory changes during seed development due to disrupted amylose synthesis. This included altered starch granule structure, enhanced lipid profiles, and reduced carbohydrate content. Differentially expressed genes and transcription factors related to starch metabolism provided insights into the regulatory mechanisms. Furthermore, metabolic profiling showed significant changes in the accumulation of compounds influencing flavor and nutritional properties. This study enhances our understanding of the molecular coordination of sorghum seed development and provides new insights into regulating seed development.
Project description:One clear hallmark of mammalian promoters is the presence of CpG islands (CGIs) at more than two thirds of genes whereas TATA boxes are only present at a minority of promoters. Using genome-wide approaches, we show that GC content and CGIs are major promoter elements in mammalian cells, able to govern open chromatin conformation and support paused transcription. First, we define three classes of promoters with distinct transcriptional directionality and pausing properties which correlate with their GC content. We further analyze the direct influence of GC content on nucleosome positioning and depletion, and show that CGIs correlate with nucleosome depletion both in vivo and in vitro. We also show that transcription is not essential for nucleosome exclusion but influences both a weak +1 and a well-positioned nucleosome at CGI borders. Altogether our data support the idea that CGIs have become an essential feature of promoter structure defining novel regulatory properties in mammals. Nucleosome density and positioning were studied by high-throughput sequencing of DNA previously treated with Mnase. In parallel, chIPseq for PolII and H3K27ac were performed in mouse and human with different conditions to assess a potential effect of transcription on nucleosomes properties.
Project description:One clear hallmark of mammalian promoters is the presence of CpG islands (CGIs) at more than two thirds of genes whereas TATA boxes are only present at a minority of promoters. Using genome-wide approaches, we show that GC content and CGIs are major promoter elements in mammalian cells, able to govern open chromatin conformation and support paused transcription. First, we define three classes of promoters with distinct transcriptional directionality and pausing properties which correlate with their GC content. We further analyze the direct influence of GC content on nucleosome positioning and depletion, and show that CGIs correlate with nucleosome depletion both in vivo and in vitro. We also show that transcription is not essential for nucleosome exclusion but influences both a weak +1 and a well-positioned nucleosome at CGI borders. Altogether our data support the idea that CGIs have become an essential feature of promoter structure defining novel regulatory properties in mammals. Nucleosome density and positioning were studied by high-throughput sequencing of DNA previously treated with Mnase. In parallel, chIPseq for PolII and H3K27ac were performed in mouse and human with different conditions to assess a potential effect of transcription on nucleosomes properties.
Project description:Improvement of feed efficiency would increase profitability of the poultry industries by decreasing the amount of feed required for production. Korat (KR) chicken is a new alternative meat-type chicken breed which its meat is recognized for its high protein, low fat and low purine content, whereas its low feed efficiency leads to high cost of production. Deeper understanding on how feed efficiency influences meat quality is poorly elucidated. To fulfill deeper understand molecular key that point the variation in feed efficiency and meat quality, the aim of this study was to investigate molecular pathways and genes involved in feed efficiency and meat quality in thigh of slow-growing KR chicken. A total of 75 males KR chicken were reared in individual cage until 10 weeks of age. Individual feed intake and body weight were collected weekly to calculate Feed Conversion Ratio (FCR) and Residual Feed Intake (RFI). Meat quality parameters were measured in thigh muscles such as ultimate pH (pHu), water-holding capacity (WHC), drip loss (DL), nucleotides content and several biomolecules (amide, …). Base on extreme values of FCR at 10 weeks of ages, 12 birds from the high FCR group (HFCR) and 9 birds from the low FCR group (LFCR) were selected for investigating their transcriptome using an 8×60K Agilent chicken microarray. In addition, a weighted gene coexpression network analysis was performed to detect the relationship between modules of co-expressed genes and feed efficiency, meat quality in thigh muscle. The result in this study indicated that selection on feed efficiency (FCR, RFI) would affect flavor precursor, lipid and protein content in thigh muscle. Based on WGCNA and functional enrichment analysis, results suggested that the key molecular pathways relate to FCR, RFI and meat quality (WHC, DL, IMP, AMP and inosine) in thigh muscle were the pathways of regulation of biological process, biological regulation and regulation of metabolic. Moreover, we revealed four genes there are assembly competence domain (ACD) gene, baculoviral IAP repeat containing 5 (BIRC5) gene, cytochrome c oxidase assembly factor 3 (COA3) gene and myosin light chain 9 (MYL9) gene that might be biomarker gene in feed efficiency and meat quality in thigh muscle. The hypothesis of the current study was alteration feed efficiency in slow-growing chicken will impact meat quality especially in term of texture and flavor.
Project description:One clear hallmark of mammalian promoters is the presence of CpG islands (CGIs) at more than two thirds of genes whereas TATA boxes are only present at a minority of promoters. Using genome-wide approaches, we show that GC content and CGIs are major promoter elements in mammalian cells, able to govern open chromatin conformation and support paused transcription. First, we define three classes of promoters with distinct transcriptional directionality and pausing properties which correlate with their GC content. We further analyze the direct influence of GC content on nucleosome positioning and depletion, and show that CGIs correlate with nucleosome depletion both in vivo and in vitro. We also show that transcription is not essential for nucleosome exclusion but influences both a weak +1 and a well-positioned nucleosome at CGI borders. Altogether our data support the idea that CGIs have become an essential feature of promoter structure defining novel regulatory properties in mammals. Nucleosome density and positioning were studied by high-throughput sequencing of DNA previously treated with Mnase. In parallel, chIPseq for PolII and H3K27ac were performed in mouse and human with different conditions to assess a potential effect of transcription on nucleosomes properties. Sonicated genomic DNA has been sequenced to quantify and exclude sequencing bias in the largest CGIs regions studied in this article.
Project description:Background: Marketing products with added-value characteristics is a current trend in livestock production systems. Regarding meat, selection for intramuscular fat and muscular fatty acid composition is a way to improve the palatability and juiciness of meat while assuring a healthy fat content. This represents selecting animal with a different muscular metabolic profile with respect to the extended selection of lean animals. Results: The present study has analysed the muscular gene expression profiles of 68 commercial Duroc pigs belonging to two groups with extreme phenotypes for traits strongly related with lipid deposition and composition. This has allowed us to compare the physiological and metabolic implications of selecting for each of these extreme groups. Rather than upregulation of a single pathway, the main differences lied on the transcriptional levels of genes related with lipogenesis and lipolysis, revealing the existence of a cycle where triacylglycerols are continuously synthesized and degraded. Most strikingly, several genes which enhanced fatty acid β-oxidation and favoured insulin signalling and glucose uptake were upregulated in the fattest animals, indicating that the events leading to peripheral insulin resistance in humans with increased levels of intramuscular fat and obesity do not take place in these pigs. Moreover, neither was detected the well-characterised low-grade inflammatory state observed in overweighed humans. Conclusion: As a whole, our data suggest that selection for increasing intramuscular fat content in pigs would lead to a shift but not a disruption of the metabolic homeostasis of muscle cells. Future studies on the post-translational changes affecting protein activity or expression as well as information about protein location within the cell would be needed to fully understand how lipid deposition affects muscle physiology in pigs. 68 gluteus medius samples form 68 animals belonging to two groups of 34 animals each: HIGH group had higher carcass, plasma and muscle fat content; LOW group had lower carcass, plasma and muscle fat content