Other Genetics and Genomics Commons^™

Charge Modulation Of Peptide/Nucleic Acid Complexes: An Anionic Additive Enhances Gene Silencing And Crispr/Cas9 Editing By Promoting Intracellular Nucleic Acid Release, Abdulelah Alhazza, Sorour Khayyatnejad Shoushtari, Hasan Uludag, Keykavous Parang, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

Introduction: Small interfering RNA (siRNA) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated Protein 9 (Cas9) complexes are effective approaches to temporarily downregulate protein expression via post-transcription RNA interference or permanently altering protein expression via editing genomic DNA, respectively. However, the efficient delivery of these mediators to targeted cells has been challenging, largely due to their anionic and hydrophilic nature, which hinders their interaction with the cell membrane and cellular internalization. Cell-penetrating peptides (CPPs) exhibit dual characteristics as a carrier for nucleic acid delivery, where positively charged components bind to the negatively charged nucleic acid, and the hydrophobic components …

Homocysteine Thiolactone From Translation Proofreading Is An Endogenous Ligand For Cell-Cell Signaling By The Receptor Sdia, Lorenzo Eugenio Leiva, Roberto A. Zúñiga, Gregory J. Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Several widespread mechanisms enable cellular communication and coordinate the behavior of bacterial populations. The modules responsible for cellular communication are often found in matching pairs: an enzyme that synthesizes a signal molecule and a specific receptor that decodes it. A notable exception is Escherichia coli SdiA, a homolog of known N-acyl-homoserine lactone (AHL) receptors, for which no corresponding AHL synthase exists. SdiA is an orphan receptor that enables cross-talk by sensing AHLs from other bacterial species. In this work, we investigated whether homocysteine thiolactone (HTL), an AHL-like molecule arising from a proofreading reaction of methionyl tRNA synthetase (MetRS) to correct …

Deconstructing Systemic Sclerosis Heterogeneity: From Patient Subtypes To Pathogenic Fibroblasts, Rezvan Parvizi

Dartmouth College Ph.D Dissertations

This thesis advances heterogeneity as the central barrier both to interpreting therapeutic response and to identifying the molecular regulators that drive fibrosis in systemic sclerosis (SSc). In SSc, heterogeneity is manifest at every level at which the disease can be measured: clinically, in the variable extent of skin and organ involvement; molecularly, in the distinct gene-expression programs that distinguish otherwise comparable patients; and cellularly, in the diverse fibroblast populations from which the fibrotic signal ultimately arises.

Leveraging longitudinal skin transcriptomics from a large cohort treated with mycophenolate mofetil (MMF), the first study demonstrates that intrinsic molecular subtypes are dynamic rather …

Mobile Genetic Elements Shape Microbial Diversity And Functions In Thawing Permafrost Soils, Jiarong Guo, Samuel T. N. Aroney, Guillermo Domínguez-Huerta, Derek Smith, Dean Vik, Carlos Owusu-Ansah, Akbar Adjie Pratama, Sergei Solonenko, Funing Tian, Cristina Howard-Varona, Zhi-Ping Zhong, Aminata Fofana, Garrett J. Smith, Suzanne B. Hodgkins, Dylan Cronin, Isogenie Field Teams 2010–2017, 2019, Emerge Coordinators, Ben J. Woodcroft, Gene W. Tyson, Virginia I. Rich, Matthew B. Sullivan, Simon Roux, Sarah C. Bagby, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ecosystems are shaped by communities of microorganisms whose niches and impacts depend on functional profiles influenced by gene gains and losses. Culture-based experiments demonstrate that mobile genetic elements (MGEs) can mediate gene flux, but quantitative understanding of these dynamics in natural systems remains limited. Here we develop and apply a systematic, meta-omic framework to investigate MGEs in a complex natural system using an 8-year soil time series collected at Stordalen Mire, in Sweden’s thawing permafrost margin. In this climate-critical peatland, we identify ~2.1 million MGE recombinases across 89 microbial phyla and assess ecological distributions, affected functions, past mobility and current …

The Competition Between Splicing And 3′ Processing Shapes The Human Transcriptome, Lindsey V. Soles, Shuangyu Li, Liang Liu, Kristianna S.K. Sarkan, Erik G. Alvstad, Lusong Tian, Yoseop Yoon, Marielle Valdez, Ivan Marazzi, Yongsheng Shi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Eukaryotic pre-mRNA processing steps, including splicing and 3′ processing, are tightly coordinated, yet the underlying mechanisms remain incompletely understood. U1 snRNP has been proposed to inhibit 3′ processing at intronic polyadenylation (IPA) sites through a splicing-independent mechanism termed telescripting. In contrast, we discovered that disrupting splicing by using six different methods—targeting various key components such as U1 snRNP, U2 snRNP, U2AF, and SF3b—activates 3′ processing at thousands of IPA sites. Notably, splicing inhibition, especially of U1 snRNP, induced widespread premature transcription termination within gene bodies through both IPA-coupled and IPA-independent mechanisms. Inhibition of different splicing factors activated overlapping and distinct …

Effects Of M6a Dna Methylation By Bacterial Methyltransferase In Colorectal Cancer, Fabian Alejandro Mendoza Galvan

Dissertations and Theses (Open Access)

Effects of m6A DNA methylation by bacterial methyltransferase in colorectal cancer Fabian Alejandro Mendoza Galvan Advisory Professor: Angela H. Ting, Ph.D. Fusobacterium nucleatum animalis (Fna) is found in the human oral cavity and gut. A distinct clade of Fna is primarily enriched in the tumor microenvironment (TME) and within colorectal cancer (CRC) cells. This clade DNA methylation pattern is primarily catalyzed by a cell-cycle regulated methyltransferase (CcrM) ortholog, M.FnI, that targets the GANTC sequence motif through methyl-6-Adenine (m6A) DNA methylation. We hypothesized that M.FnI enzyme can induce m6A methylation abnormalities in CRC cells to promote cancer progression. Evidence for endogenous …

Reverse Micelles Produce Hydroxyapatite Nanoparticles As More Efficient Gene Delivery Carriers Than Regular Micelles, Vuk Uskoković

Administration and Staff Articles and Research

Hydroxyapatite (HAp) is an effective inorganic gene delivery carrier due to its ability to transport genetic cargo across cell membranes, protect it from proteolysis, and enable escape from late endosomes via pH-controlled dissolution. However, its transfection efficiency remains lower than that of viral agents, prompting studies of hybrids with cationic molecules or phases to enhance the gene delivery performance. This study reports on the synthesis of HAp in regular and reverse micellar regions of a ternary microemulsion system composed of cetyltrimethylammonium bromide (CTAB), 1-hexanol and water. Spectroscopic characterization revealed that CTAB headgroups adopted more ordered supramolecular conformations in reverse micelles …

A Framework For Characterizing The Peripheral Immune Isonome Using Long-Read Single-Cell Rna Sequencing And Its Relevance To Neurological Disease, Patricia Hayes Doyle

Theses and Dissertations--Neuroscience

Long-read single-cell RNA sequencing provides an opportunity to understand human health and disease at isoform resolution, revealing cellular diversity and disease mechanisms difficult to resolve with bulk or short-read methodologies.

Using a modified PIPseq workflow and computational pipeline adapted for Oxford Nanopore (ONT) sequencing, we profiled isoform usage across immune cells, integrating marker expression and isoform discovery, generating the largest long-read single-cell dataset of human immune cells from a single individual to date. We identified non-canonical protein-coding variants of GZMB and CD3G enriched in unexpected cell types. We also discovered novel transcripts from CMC1 and LYAR with cell-type-specific signatures that …