Project description:In this project, seedlings of tomato (Solanum lycopersicum) ‘Money Maker’ plants overexpressing a glyoxalase I gene were treated under 20 µM Al3+ and salt (200 mM NaCl) for two weeks. The treatments were conducted in hydroponic solutions in a greenhouse at 24±2C without supplemental light. Roots harvested were immediately frozen in liquid nitrogen and stored at -80 oC. The treatment experiment was conducted at Agricultural Research Station, Tennessee State University, Nashville, TN 37209
Project description:In this project, seedlings of tomato (Solanum lycopersicum) ‘Money Maker’ plants transformed with a bar gene were treated under 20 µM Al3+ and salt (200 mM NaCl) for two weeks. The treatments were conducted in hydroponic solutions in a greenhouse at 24±2C without supplemental light. Roots harvested were immediately frozen in liquid nitrogen and stored at -80 oC. The treatment experiment was conducted at Agricultural Research Station, Tennessee State University, Nashville, TN 37209
Project description:Transcriptional profiling of adult mouse liver tissue comparing offspring derived from sperm and seminal plasma of normal protein diet fed males (controls, NN), sperm and seminal plasma from males fed a low protein diet fed males (LL), sperm from normal protein fed males and seminal plasma from low protein fed males (NL) or sperm from low protein diet fed males and seminal plasma from normal protein diet males (NL). The first letter denotes the diet of the sperm donor and the second letter the diet of the seminal plasma donor. Three-condition experiment: NN vs. LL, NN vs. NL, NN vs. LN. Adult offspring liver tissue. Biological replicates: 7 control (NN), 9 LL, 7 NL and 7 LN. One replicate per array chip.
Project description:In this study, we profiled genome-Nuclear Lamina (NL) contacts during the first stages of mouse embryonic development. We discovered a remarkable cell-to-cell variability in NL-contacts at the 2-cell stage, which is particularly strong on the paternal allele. We additionally obtained single-cell profiles for H3K27me3, H3K9me3 and DNA accessibility at this stage, but did not observe the same large-scale variability. The variability in NL-contacts did not appear to affect the transcription of underlying genes. Comparing NL-contact profiles with diverse histone modification profiles showed that large regions of typical NL-contacts are lost and instead are enriched for H3K27me3 during early development. To investigate the relationship between H3K27me3 and NL association, we used a conditional EED KO mouse model, which results in an absence of H3K27me3 during oocyte development and the early embryo. Profiling NL-contacts at the 2-cell stage in this system revealed that regions enriched with H3K27me3 in WT regain NL association in the EED maternal KO. In addition, the loss of H3K27me3 resulted in more similar NL association profiles on the maternal and paternal allele. Together, these results suggest that H3K27me3 antagonizes NL association and that the non-canonical broad H3K27me3 domains present in the early embryo may be responsible for the early-embryo specific loss of NL associations in these regions.
Project description:In this study, we profiled genome-Nuclear Lamina (NL) contacts during the first stages of mouse embryonic development. We discovered a remarkable cell-to-cell variability in NL-contacts at the 2-cell stage, which is particularly strong on the paternal allele. We additionally obtained single-cell profiles for H3K27me3, H3K9me3 and DNA accessibility at this stage, but did not observe the same large-scale variability. The variability in NL-contacts did not appear to affect the transcription of underlying genes. Comparing NL-contact profiles with diverse histone modification profiles showed that large regions of typical NL-contacts are lost and instead are enriched for H3K27me3 during early development. To investigate the relationship between H3K27me3 and NL association, we used a conditional EED KO mouse model, which results in an absence of H3K27me3 during oocyte development and the early embryo. Profiling NL-contacts at the 2-cell stage in this system revealed that regions enriched with H3K27me3 in WT regain NL association in the EED maternal KO. In addition, the loss of H3K27me3 resulted in more similar NL association profiles on the maternal and paternal allele. Together, these results suggest that H3K27me3 antagonizes NL association and that the non-canonical broad H3K27me3 domains present in the early embryo may be responsible for the early-embryo specific loss of NL associations in these regions.
Project description:The nuclear lamina (NL) is a meshwork of lamins and lamin-associated proteins lining the nuclear envelope (NE). Chromatin adjoining the NL in lamina-associated domains (LADs) is densely packed and contains predominantly silent genes. However, how the NL impacts on global chromatin architecture is poorly understood. Here, we show that NL disruption in Drosophila S2 cells leads to bulk chromatin compactization and repositioning from the NE. This increases the chromatin density in the topologically-associating domains (TADs) harboring active genes, and enhances inter-TAD interactions resulting in the intermingling of active and inactive compartments. Importantly, upon NL disruption, a fraction of TADs strongly overlapping with LADs becomes less compact, whilst resident genes are derepressed. Two-color FISH confirms that a a TAD is more decompacted following its release from the NL. Finally, polymer simulations show that chromatin binding to the NL can per se compact attached TADs. Collectively, our findings demonstrate a dual function of the NL in shaping the 3D genome. Attachment of TADs to the NL makes them more condensed but decreases the overall chromatin density in the nucleus by stretching interphase chromosomes.
Project description:Mammalian genomes contain hundreds of lamina-associated domains (LADs), which are large, often megabase-sized heterochromatin domains that are anchored to the nuclear lamina (NL). Even though LADs play a key role in the spatial organization of the genome and potently repress gene activity, it is not yet understood how their interactions with the NL are encoded in their DNA. Here, we investigated the principles that govern LAD-NL interactions by taking a "LAD scrambling" approach. This approach relies on 1) local "hopping" of a Sleeping Beauty transposon to randomly insert loxP sites within and around a LAD of choice; and 2) Cre-mediated recombination between the loxP sites. This approach is highly efficient, enabling us to establish a large collection of clonal cell lines with deletions and inversions up to ~2Mb in size, spanning LAD and their flanking inter-LAD sequences. Mapping of NL interactions in these clones revealed that a single LAD contacts the NL through multiple regions. These regions act cooperatively and redundantly; however, some have more affinity for the NL and can boost NL contacts of neighbouring sequences. We also observed a crosstalk between two neighbouring LADs, when close enough to each other. Finally, changes in the heterochromatin mark H3K9me3 only partially mirrored changes in NL contacts. They also correlated more with gene expression changes than NL contacts did. These principles of LAD - NL interactions provide insight into the overall architecture of the genome and the impact on gene regulation.