Project description:MicroRNAs (miRNAs) play key roles in plant reproduction. However, knowledge on microRNAome analysis in autotetraploid rice is rather limited. Here, high-throughput sequencing technology was employed to analyze miRNAomes during pollen development in autotetraploid rice. A total of 172 differentially expressed miRNAs (DEM) were detected in autotetraploid rice compared to its diploid counterpart, and 57 miRNAs were specifically expressed in autotetraploid rice. Of the 172 DEM, 115 and 61 miRNAs were found to be up-regulated and down-regulated, respectively. Gene Ontology analysis on the targets of up-regulated DEM showed that they were enriched in transport and membrane in pre-meiotic interphase, reproduction in meiosis, and nucleotide binding in single microspore stage. osa-miR5788 and osa-miR1432-5p_R+1 were up-regulated in meiosis and their targets revealed interaction with the meiosis-related genes, suggesting that they may involve in the genes regulation associated with the chromosome behavior. Abundant 24-nt siRNAs associated with transposable elements were found in autotetraploid rice during pollen development; however, they significantly declined in diploid rice, suggesting that 24-nt siRNAs may play a role in pollen development. These findings provide a foundation for understanding the effect of polyploidy on small RNA expression patterns during pollen development that lead to low pollen fertility in autotetraploid rice.
Project description:Background: Partial pollen and embryo sac sterilities are the two main reasons for low fertility in autotetraploid rice. Our previous study revealed that small RNAs changes may associate with pollen fertility in autotetraploid rice. However, knowledge on comparative analysis between the development of pollen and embryo sac by small RNAs in autotetraploid rice is still unknown. In the present study, WE-CLSM (whole-mount eosin B-staining confocal laser scanning microscopy) and high-throughput sequencing technology was employed to examine the cytological variations and to analyze small RNAs changes during pollen and embryo sac development in autotetraploid rice compared with its diploid counterpart. Results: A total of 321 and 368 differentially expressed miRNAs (DEM) were detected during development of pollen and embryo sac in autotetraploid rice, respectively. Gene Ontology enrichment analysis on the targets of miRNAs-enriched during the development of pollen and embryo sac in autotetraploid rice revealed 30 prominent functional gene classes, such as cell differentiation and signal transduction during embryo sac development. However, only 7 prominent functional gene classes, such as flower development and transcription factor activity, were detected during pollen development. The expression levels of 39 DEM, which revealed interaction with meiosis-related genes, showed opposite expression levels in pollen and embryo sac development. Of these DEM, osa-miR1436_L+3_1ss5CT and osa-miR167h-3p were associated with the female meiosis, while osa-miR159a.1 and osa-MIR159a-p5 were related with the male meiosis. 21nt-phasiRNAs were detected both during pollen and embryo sac development, while 24nt-phasiRNAs were found only in pollen development, which displayed down-regulation in autotetraploid compared to diploid rice and their spatial-temporal expression patterns were similar to osa-miR2275d. 24nt TEs-siRNAs were found to be up-regulated in embryo sac but down-regulated in pollen development. Conclusion: The above results not only provide the small RNAs changes during four landmark stages of pollen and embryo sac development in autotetraploid rice but also have identified specifically expressed miRNAs, especially meiosis-related miRNAs, pollen-24nt-phasiRNAs and TEs-siRNAs in autotetraploid rice. Together, these findings provide a foundation for understanding the effect of polyploidy on small RNAs expression patterns during pollen and embryo sac development that may lead to different abnormalities in autotetraploid rice.
Project description:The human genome shares a remarkable amount of genomic sequence with our closest living primate relatives. Researchers have long sought to understand what regions of the genome are responsible for unique species-specific traits. Previous studies have shown that many genes are differentially expressed between species, but the regulatory elements contributing to these differences are largely unknown. Here we report a genome-wide comparison of active gene regulatory elements in human, chimpanzee, and macaque, and we identify hundreds of regulatory elements that have been gained or lost in the human or chimpanzee genomes since their evolutionary divergence. These elements contain evidence of natural selection and correlate with species-specific changes in gene expression. Polymorphic DNA bases in transcription factor motifs that we found in these regulatory elements may be responsible for the varied biological functions across species. This study directly links phenotypic and transcriptional differences between species with changes in chromatin structure. One biological replicate was analyzed for each of the 15 primate samples using DNase-seq.
Project description:<p>Pigmented rice (<em>Oryza sativa L.</em>) is a rich source of nutrients, but pigmented lines typically have long life cycles and limited productivity. Here we generated genome assemblies of 5 pigmented rice varieties and evaluated the genetic variation among 51 pigmented rice varieties by resequencing an additional 46 varieties. Phylogenetic analyses divided the pigmented varieties into four varietal groups: Geng-japonica, Xian-indica, circum-Aus and circum-Basmati. Metabolomics and ionomics profiling revealed that black rice varieties are rich in aromatic secondary metabolites. We established a regeneration and transformation system and used CRISPR-Cas9 to knock out three flowering time repressors (Hd2, Hd4 and Hd5) in the black Indonesian rice Cempo Ireng, resulting in an early maturing variety with shorter stature. Our study thus provides a multi-omics resource for understanding and improving Asian pigmented rice.</p>
Project description:The human genome shares a remarkable amount of genomic sequence with our closest living primate relatives. Researchers have long sought to understand what regions of the genome are responsible for unique species-specific traits. Previous studies have shown that many genes are differentially expressed between species, but the regulatory elements contributing to these differences are largely unknown. Here we report a genome-wide comparison of active gene regulatory elements in human, chimpanzee, and macaque, and we identify hundreds of regulatory elements that have been gained or lost in the human or chimpanzee genomes since their evolutionary divergence. These elements contain evidence of natural selection and correlate with species-specific changes in gene expression. Polymorphic DNA bases in transcription factor motifs that we found in these regulatory elements may be responsible for the varied biological functions across species. This study directly links phenotypic and transcriptional differences between species with changes in chromatin structure.
Project description:Lizards cannot naturally regenerate limbs but are the closest known relatives of mammals capable of epimorphic tail regrowth. However, the mechanisms regulating lizard blastema derivation and chondrogenesis remain unclear. We utilized single-cell RNA sequencing analyses of regenerating lizard tails throughout the course of regeneration to assess diversity and heterogeneity in regeneating tail cell populations.
Project description:The human genome shares a remarkable amount of genomic sequence with our closest living primate relatives. Researchers have long sought to understand what regions of the genome are responsible for unique species-specific traits. Previous studies have shown that many genes are differentially expressed between species, but the regulatory elements contributing to these differences are largely unknown. Here we report a genome-wide comparison of active gene regulatory elements in human, chimpanzee, and macaque, and we identify hundreds of regulatory elements that have been gained or lost in the human or chimpanzee genomes since their evolutionary divergence. These elements contain evidence of natural selection and correlate with species-specific changes in gene expression. Polymorphic DNA bases in transcription factor motifs that we found in these regulatory elements may be responsible for the varied biological functions across species. This study directly links phenotypic and transcriptional differences between species with changes in chromatin structure. DGE-seq
Project description:While the next generation sequencing technology is accelerating the discovery of sites in RNA editing, the strategies to accurately identify the editome, the mechanism by which its profile is maintained and its functional significance remain controversial. Here, 90bp × 2, paired-end, strand-specific, polyA-postive RNA-Seq were performed in 3 rhesus monkey tissues, and 90bp × 2, paired-end, whole exome sequencing was performed in blood cells. Combining genome-wide identification and other quality control in multiple tissues from the same individual, we identified a list of editing sites in coding regions from the rhesus macaque, one of our closest evolutionary relatives. Low-scale verification validated all of these sites and the corresponding levels of editing. The editome in macaque coding region suggests RNA editing as a type of controlled, conserved regulation shaped by purifying selection. This submission represents RNA-Seq: cerebellum, lung, kidney and heart component of study.