コウソウ スサビノリ ニ オケル コピア ヨウ レトロトランスポゾン ノ タンリ ト カイセキ

Retrotransposons, which transpose through the reverse transcription of their mRNAintermediate, are the most abundant and widespread class of eukaryotic transposableelements. They are separated into two broad groups, the long terminal repeat (LTR) andnon-LTR retrotransposons. LTR retrotransposons are further classified into two major groups, the copia and gypsy. The two types can be distinguished by the inversed order of the gene arrangement of integrase and RT/RNase H. Both types have provided potential tools for the basic and applied studies in plant biology. Porphyra yezoensis has been using for cultivation of seaweed and most important in the fishery industry of Japan. In addition, it has recently received much attention as a model for fundamental research on marine plants. Hence, retrotransposons are also expected to be valuable tools for the research in Porphyra. There are, however, no reports on LTR retrotransposons in macro algae including Porphyra. In my studies for a doctor\u27s degree, I addressed elucidation ofthe nature of two copia-like retrotransposons from P. yezoensis

5S ribosomal RNA is an essential component of a nascent ribosomal precursor complex that regulates the Hdm2-p53 checkpoint

Recently, we demonstrated that RPL5 and RPL11 act in a mutually dependent manner to inhibit Hdm2 and stabilize p53 following impaired ribosome biogenesis. Given that RPL5 and RPL11 form a preribosomal complex with noncoding 5S ribosomal RNA (rRNA) and the three have been implicated in the p53 response, we reasoned they may be part of an Hdm2-inhibitory complex. Here, we show that small interfering RNAs directed against 5S rRNA have no effect on total or nascent levels of the noncoding rRNA, though they prevent the reported Hdm4 inhibition of p53. To achieve efficient inhibition of 5S rRNA synthesis, we targeted TFIIIA, a specific RNA polymerase III cofactor, which, like depletion of either RPL5 or RPL11, did not induce p53. Instead, 5S rRNA acts in a dependent manner with RPL5 and RPL11 to inhibit Hdm2 and stabilize p53. Moreover, depletion of any one of the three components abolished the binding of the other two to Hdm2, explaining their common dependence. Finally, we demonstrate that the RPL5/RPL11/5S rRNA preribosomal complex is redirected from assembly into nascent 60S ribosomes to Hdm2 inhibition as a consequence of impaired ribosome biogenesis. Thus, the activation of the Hdm2-inhibitory complex is not a passive but a regulated event, whose potential role in tumor suppression has been recently noted

Paired mutations abolish and restore the balanced annealing and melting activities of ORF1p that are required for LINE-1 retrotransposition

Retrotransposition amplifies LINE-1 (L1) to high copy number in mammalian genomes. The L1 protein encoded by ORF1 (ORF1p) is required for retrotransposition. This dependence on ORF1p was investigated by mutating three highly conserved residues, R238, R284 and Y318 to alanine, thereby inactivating retrotransposition. R284A and Y318A were rescued by further substituting the alanine with the appropriate conservative amino acid, e.g. lysine or phenylalanine, respectively, whereas R238K remained inactive. Quantification of the steady-state levels of L1 RNA and ORF1p failed to discriminate active from inactive variants, indicating loss of L1 retrotransposition resulted from loss of function rather than reduced expression. The two biochemical properties known for ORF1p are high-affinity RNA binding and nucleic acid chaperone activity. Only R238A/K exhibited significantly reduced RNA affinities. The nucleic acid chaperone activities of the remaining paired mutants were assessed by single-molecule DNA stretching and found to mirror retrotransposition activity. To further examine ORF1p chaperone function, their energetic barriers to DNA annealing and melting were derived from kinetic work. When plotted against each other, the ratio of these two activities distinguished functional from non-functional ORF1p variants. These findings enhance our understanding of the requirements for ORF1p in LINE-1 retrotransposition and, more generally, nucleic acid chaperone function

Playing Field Evaluations for M-NCPPC

Final Project for PLSC402: Sports Turf Management (Fall 2020). University of Maryland, College Park.Students in PLSC402 worked with Prince George’s County Department of Parks and Recreation to assist the department in improving the maintenance practices on some of their sports fields to provide safe, agronomically sound play areas for county residents and amateur sports teams. Students provided assistance in creating a “turf inventory” on the county’s recreational sports fields and Board of Education fields, which the Department of Parks and Recreation may take over in the near future. While it wasn’t feasible within the framework of the class to examine every sports field, PLSC402 “Sports Turf Management” students examined and researched three fields, which were representative of other county field conditions and traffic and play patterns. The results of standard sports turf field assessment measurements, including shear strength, surface hardness, bulk density, and volumetric water content, are included in this report. Based on these findings, field visits, and observations agronomic recommendations were developed and included in this report

The Endosomal Escape Vehicle Platform Enhances Delivery of Oligonucleotides in Preclinical Models of Neuromuscular Disorders

Biological therapeutic agents are highly targeted and potent but limited in their ability to reach intracellular targets. These limitations often necessitate high therapeutic doses and can be associated with less-than-optimal therapeutic activity. One promising solution for therapeutic agent delivery is use of cell-penetrating peptides. Canonical cell-penetrating peptides, however, are limited by low efficiencies of cellular uptake and endosomal escape, minimal proteolytic stability, and toxicity. To overcome these limitations, we designed a family of proprietary cyclic cell-penetrating peptides that form the core of our endosomal escape vehicle technology capable of delivering therapeutic agent-conjugated cargo intracellularly. We demonstrated the therapeutic potential of this endosomal escape vehicle platform in preclinical models of muscular dystrophy with distinct disease etiology. An endosomal escape vehicle-conjugated, splice-modulating oligonucleotide restored dystrophin protein expression in striated muscles in the mdx mouse, a model for Duchenne muscular dystrophy. Furthermore, another endosomal escape vehicle-conjugated, sterically blocking oligonucleotide led to knockdown of aberrant transcript expression levels in facioscapulohumeral muscular dystrophy patient-derived skeletal muscle cells. These findings suggest a significant therapeutic potential of our endosomal escape vehicle conjugated oligonucleotides for targeted upregulation and downregulation of gene expression in neuromuscular diseases, with possible broader application of this platform for delivery of intracellular biological agents

The impact of transposable elements on mammalian development

Despite often being classified as selfish or junk DNA, transposable elements (TEs) are a group of abundant genetic sequences that have a significant impact on mammalian development and genome regulation. In recent years, our understanding of how pre-existing TEs affect genome architecture, gene regulatory networks and protein function during mammalian embryogenesis has dramatically expanded. In addition, the mobilization of active TEs in selected cell types has been shown to generate genetic variation during development and in fully differentiated tissues. Importantly, the ongoing domestication and evolution of TEs appears to provide a rich source of regulatory elements, functional modules and genetic variation that fuels the evolution of mammalian developmental processes. Here, we review the functional impact that TEs exert on mammalian developmental processes and discuss how the somatic activity of TEs can influence gene regulatory networks.</p

ASSESING THE ASSOCIATION OF NUTRITION EDUCATION ON FOOD SECURITY, DIETARY DIVERSITY, AND DIET QUALITY IN HOUSEHOLDS WITH LOW-INCOME

Food insecurity continues to disproportionately affect households with low-income, compromising dietary quality and long-term health. The Expanded Food and Nutrition Education Program (EFNEP) seeks to address these disparities through culturally tailored, evidence-based nutrition education. This quasi-experimental longitudinal study assessed the impact of nutrition education delivered through EFNEP on dietary diversity, diet quality, and food security among low-income adults in Prince George’s County, Maryland. Participants (n=86) were divided into control (n=43) and intervention groups (n=43). The intervention group received EFNEP’s structured curriculum focused on dietary behaviors, food resource management, and nutrition education. Data were collected at baseline, post (6-week exit), and 6-month follow-up using 24-hour dietary recalls and EFNEP Adult Behavior Questionnaires. Dietary quality was assessed using the Healthy Eating Index (HEI-2015), and dietary diversity was evaluated via the Minimum Dietary Diversity Score for Women (MDD-W), adapted for all participants. Results indicated that the intervention group showed improvements across all outcome domains, including increased HEI and MDD-W scores, enhanced food security, and better food resource management and preparation skills. These gains were sustained at the 6-month follow-up, suggesting benefits of nutrition education participation. In contrast, the control group demonstrated either stagnation or decline in key metrics. This study provides evidence that community-based nutrition education programs like EFNEP can lead to sustained improvements in dietary practices and food security among underserved populations. The findings support expanding and integrating such programs into broader public health strategies to promote nutritional equity and long-term health outcomes

Understanding organic and conventional management programs and rhizosphere microbiome for sports turf in Maryland

In response to public concerns about exposure to pesticides, some state and local municipalities have placed restrictions on the use of pesticides on athletic fields. When such restrictions are implemented athletic field management often transitions to the use of natural or organic turf care with little understanding of how the transition away from conventional management practices may affect surface conditions and soil microbial properties.This thesis examined the use of organic and conventional management programs on the turf quality, surface hardness, and shear strength of engineered soil cap, hybrid bermudagrass (Cynodon dactylon x Cynodon transvaalensis) athletic fields, as well as the impact of the two programs on the rhizosphere microbiome. Turf quality was assessed by visual means and by obtaining normalized difference vegetative index (NDVI) readings of the turf canopy. Surface hardness was determined using a Clegg impact surface tester. The rotational shear strength of the surface was measured using a shear vane. The study was conducted for 3 years at two different locations; research plots at the University of Maryland Research Facility and on athletic fields at Laytonia Recreational Park, in Gaithersburg, MD. Surface property data was collected monthly. Turf visual quality and NDVI data revealed use of the organic management program led to higher visual quality during spring, which was primarily the result of the spring retention of fall overseeded intermediate ryegrass (Lolium x hybridum Hausskn) and early season use of natural based fertilizers. In the summer months, crabgrass (Digitaria ischaemum Schreb.) encroachment was limited to the organically managed turfgrass. At both locations, clover (Trifolium repens) encroachment developed by the third year of the study, but the presence of this weed had limited impact on turfgrass quality. There were few significant differences in surface hardness and shear strength between the two management practices over the entire study period. The rhizosphere microbiome data, which was collected 12, 20, and 24 months after the initiation of two programs, did not show any significant difference between the organic and conventional management athletic fields in microbial abundance and/or diversity. The results of this study emphasize that the adoption of organic management programs on bermudagrass athletic fields should, in most instances, center on the establishment of acceptable weed tolerance levels for these fields. The use of organic management programs in the transition zone offers a viable alternative to the conventional chemical management of athletic fields, however over time, growing weed seed banks may necessitate the need for the occasional use of conventional herbicide materials