Life Sciences Commons^™

Characterization Of The Recombination Activities Of The Entamoeba Histolytica Rad51 Recombinase, Andrew A. Kelso, Steven D. Goodson, Suchitra Chavan, Amanda F. Say, Audrey Turchick, Deepti Sharma, Leanna L. Ledford, Erin Ratterman, Kristin Leskoske, Ada V. King, Christopher C. Attaway, Yura Bandera, Stephen H. Foulger, Alexander V. Mazin, Lesly A. Temesvari, Michael G. Sehorn

Publications

The protozoan parasite responsible for human amoebiasis is Entamoeba histolytica. An important facet of the life cycle of E. histolytica involves the conversion of the mature trophozoite to a cyst. This transition is thought to involve homologous recombination (HR), which is dependent upon the Rad51 recombinase. Here, a biochemical characterization of highly purified ehRad51 protein is presented. The ehRad51 protein preferentially binds ssDNA, forms a presynaptic filament and possesses ATP hydrolysis activity that is stimulated by the presence of DNA. Evidence is provided that ehRad51 catalyzes robust DNA strand exchange over at least 5.4 kilobase …

Approximate Time To Steady-State Resting Energy Expenditure Using Indirect Calorimetry In Young, Healthy Adults, Collin J. Popp, Jocelyn J. Tisch, Kenan E. Sakarcan, William C. Bridges, Elliot D. Jesch

Publications

Indirect calorimetry (IC) measurements to estimate resting energy expenditure (REE) necessitate a stable measurement period or steady state (SS). There is limited evidence when assessing the time to reach SS in young, healthy adults. The aims of this prospective study are to determine the approximate time to necessary reach SS using open-circuit IC and to establish the appropriate duration of SS needed to estimate REE. One hundred young, healthy participants (54 males and 46 females; age = 20.6 ± 2.1 years; body weight = 73.6 ± 16.3 kg; height 172.5 ± 9.3 cm; BMI = 24.5 ± 3.8 kg/m^{2 …}

Interleukin-17a Promotes Cd8 T Cell Cytotoxicity To Facilitate West Nile Virus Clearance, Amber M. Paul, Dhiraj Acharya, Penghua Wang, Jianfeng Dai, David Gate

Publications

CD8 T cells are crucial components of immunity and play a vital role in recovery from West Nile virus (WNV) infection. Here, we identify a previously unrecognized function of interleukin-17A (IL-17A) in inducing cytotoxic-mediator gene expression and promoting CD8 T cell cytotoxicity against WNV infection in mice. We find that IL-17A-deficient (Il17a/) mice are more susceptible to WNV infection and develop a higher viral burden than wild-type (WT) mice. Interestingly, the CD8 T cells isolated from Il17a/ mice are less cytotoxic and express lower levels of cytotoxic-mediator genes, which can be restored by supplying recombinant IL-17A in vitro and in …

Measuring The Impact Of Pollution Closures On Commercial Shellfish Harvest: The Case Of Soft-Shell Clams In Machias Bay, Maine, Keith S. Evans, Kevin Athearn, Xuan Chen, Kathleen P. Bell, Tora Johnson

Publications

Temporary closures of polluted coastal waters to shellfish harvesting protect human health but also generate broad socioeconomic impacts on rural, fishing-dependent communities. Improved understanding of these impacts could help coastal managers prioritize investments to protect water quality and mitigate the effects of coastal pollution. Using a regression model of monthly landings, we explore the impact of temporary closures on the commercial harvest of soft-shell clams (Mya arenaria) in the Machias Bay region of Maine (USA). We find that economic losses are significant and depend heavily on tidal activity, and the size, frequency and timing of closures. Over the …

The Β-Isoform Of Bccip Promotes Adp Release From The Rad51 Presynaptic Filament And Enhances Homologous Dna Pairing, Andrew A. Kelso, Steven D. Goodson, Leah E. Watts, Leanna L. Ledford, Sarah M. Waldvogel, J. Nathaniel Diehl, Shivani B. Shah, Amanda F. Say, Julie D. White, Michael G. Sehorn

Publications

Homologous recombination (HR) is a template-driven repair pathway that mends DNA double-stranded breaks (DSBs), and thus helps to maintain genome stability. The RAD51 recombinase facilitates DNA joint formation during HR, but to accomplish this task, RAD51 must be loaded onto the single-stranded DNA. DSS1, a candidate gene for split hand/split foot syndrome, provides the ability to recognize RPA-coated ssDNA to the tumor suppressor BRCA2, which is complexed with RAD51. Together BRCA2-DSS1 displace RPA and load RAD51 onto the ssDNA. In addition, the BRCA2 interacting protein BCCIP normally colocalizes with chromatin bound BRCA2, and upon DSB induction, RAD51 colocalizes with BRCA2-BCCIP …

Ectopic Expression Of A Cyanobacterial Flavodoxin In Creeping Bentgrass Impacts Plant Development And Confers Broad Abiotic Stress Tolerance, Zhigang Li, Shuangrong Yuan, Haiyan Jia, Fangyuan Gao, Qian Hu, Dongfa Sun, Hong Luo

Publications

Flavodoxin (Fld) plays a pivotal role in photosynthetic microorganisms as an alternative electron carrier flavoprotein under adverse environmental conditions. Cyanobacterial Fld has been demonstrated to be able to substitute ferredoxin (Fd) of higher plants in most electron transfer processes under stressful conditions. We have explored the potential of Fld for use in improving plant stress response in creeping bentgrass (Agrostis stolonifera L.). Overexpression of Fld altered plant growth and development. Most significantly, transgenic (TG) plants exhibited drastically enhanced performance under oxidative, drought and heat stress as well as nitrogen (N) starvation, which was associated with higher water retention and …

An Ultrasensitive Electrogenerated Chemiluminescence-Based Immunoassay For Specific Detection Of Zika Virus, Amber M. Paul, Dhiraj Acharya, Pradip Bastola, Linda Le, Estenfani Fernandez, Michael S. Diamond, Wujian Miao, Fengwei Bai

Publications

Zika virus (ZIKV) is a globally emerging mosquito-transmitted flavivirus that can cause severe fetal abnormalities, including microcephaly. As such, highly sensitive, specific, and cost-effective diagnostic methods are urgently needed. Here, we report a novel electrogenerated chemiluminescence (ECL)-based immunoassay for ultrasensitive and specific detection of ZIKV in human biological fluids. We loaded polystyrene beads (PSB) with a large number of ECL labels and conjugated them with anti-ZIKV monoclonal antibodies to generate anti-ZIKV-PSBs. These anti-ZIKV-PSBs efficiently captured ZIKV in solution forming ZIKV-anti-ZIKV-PSB complexes, which were subjected to measurement of ECL intensity after further magnetic beads separation. Our results show that the anti-ZIKV-PSBs …

Active Parental Care, Reproductive Performance, And A Novel Egg Predator Affecting Reproductive Investment In The Caribbean Spiny Lobster Panulirus Argus, J. Antonio Baeza, Lunden Simpson, Louis J. Ambrosio, Nathalia Mora, Rodrigo Guéron, Michael J. Childress

Publications

Background

We used the Caribbean spiny lobster Panulirus argus, one of the largest brooding invertebrates in the Western Atlantic, to test for the presence/absence of active parental care and to explore reproductive performance in large brooding marine organisms. Given [i] the compact and large embryo masses produced by P. argus, [ii] the expected disproportional increase in brooding costs with increasing embryo mass size, and [iii] the theoretical allometry of egg production with increasing body size, we predicted that parental females in this large species will engage in active brood care. We also predicted that larger broods from larger …

Snp-Based High Density Genetic Map And Mapping Of Btwd1 Dwarfing Gene In Barley, Xifeng Ren, Jibin Wang, Lipan Liu, Genlou Sun, Chengdao Li, Hong Luo, Dongfa Sun

Publications

A high-density linkage map is a valuable tool for functional genomics and breeding. A newly developed sequence-based marker technology, restriction site associated DNA (RAD) sequencing, has been proven to be powerful for the rapid discovery and genotyping of genome-wide single nucleotide polymorphism (SNP) markers and for the high-density genetic map construction. The objective of this research was to construct a high-density genetic map of barley using RAD sequencing. 1894 high-quality SNP markers were developed and mapped onto all seven chromosomes together with 68 SSR markers. These 1962 markers constituted a total genetic length of 1375.8 cM and an average of …

Royal Jelly Promotes Daf-16-Mediated Proteostasis To Tolerate Β-Amyloid Toxicity In C. Elegans Model Of Alzheimer’S Disease, Xiaoxia Wang, Min Cao, Yuqing Dong

Publications

Numerous studies have demonstrated that dietary intervention may promote health and help prevent Alzheimer's disease (AD). We recently reported that bee products of royal jelly (RJ) and enzyme-treated royal jelly (eRJ) were potent to promote healthy aging in C. elegans. Here, we examined whether RJ/eRJ consumption may benefit to mitigate the AD symptom in the disease model of C. elegans. Our results showed that RJ/eRJ supplementation significantly delayed the body paralysis in AD worms, suggesting the β-amyloid (Aβ) toxicity attenuation effects of RJ/eRJ. Genetic analyses suggested that RJ/eRJ-mediated alleviation of Aβ toxicity in AD worms required DAF-16, rather …

Heterologous Expression Of A Rice Mir395 Gene In Nicotiana Tabacum Impairs Sulfate Homeostasis, Ning Yuan, Shuangrong Yuan, Zhigang Li, Dayong Li, Qian Hu, Hong Luo

Publications

Sulfur participates in many important mechanisms and pathways of plant development. The most common source of sulfur in soil –SO₄²⁻– is absorbed into root tissue and distributed into aerial part through vasculature system, where it is reduced into sulfite and finally sulfide within the subcellular organs such as chloroplasts and mitochondria and used for cysteine and methionine biosynthesis. MicroRNAs are involved in many regulation pathways by repressing the expression of their target genes. MiR395 family in Arabidopsis thaliana has been reported to be an important regulator involved in sulfate transport and assimilation, and a high-affinity sulphate transporter …

Initial Movements Of A Dispersing Amphbian In Response To Partial Harvestion In The Acadian Forest Of Maine, Usa, Brittany Cline, Malcolm L. Hunter Jr.

Publications

Maintaining amphibian populations in managed forests requires a balance between timber extraction and retaining functional connectivity for animals that use multiple vegetation types to satisfy habitat requirements, particularly where extensive harvesting may increase fragmentation. Quantifying dispersal patterns in response to harvest, especially across high-contrast edges adjacent to unlogged forest, is critical for evaluating the effects of harvest configuration on amphibians. We tested the initial post-metamorphic orientation of juvenile wood frogs (Lithobates sylvaticus) at edges in harvests (31– 60% retention standwide) in the Acadian forest of Maine, USA, during the period when juveniles emigrate from breeding pools. We released juveniles (n …

Heterologous Expression Of A Rice Mir395 Gene In Nicotiana Tabacum Impairs Sulfate Homeostasis, Ning Yuan, Shuangrong Yuan, Zhigang Li, Dayong Li, Hong Luo

Publications

Sulfur participates in many important mechanisms and pathways of plant development. The most common source of sulfur in soil –SO42−– is absorbed into root tissue and distributed into aerial part through vasculature system, where it is reduced into sulfite and finally sulfide within the subcellular organs such as chloroplasts and mitochondria and used for cysteine and methionine biosynthesis. MicroRNAs are involved in many regulation pathways by repressing the expression of their target genes. MiR395 family in Arabidopsis thaliana has been reported to be an important regulator involved in sulfate transport and assimilation, and a high-affinity sulphate transporter and three ATP …

The Effects Of Rotation And River Discharge On Net Mixing In Small-Mouth Kelvin Plumes, Kelly Cole, Robert D. Hetland

Publications

Small-mouth Kelvin number plumes, or plumes with a source width smaller than the deformation radius, are characterized by near-field plume regions of rapid lateral expansion and strong vertical mixing. Net plume mixing, or the dilution of a plume by ocean water between the estuary mouth and the far-field plume, is examined using idealized numerical experiments with the Regional Ocean Modeling System (ROMS). The density anomaly of plume water entering the far field is determined from isohaline analysis of the modeled salinity field. The experiments indicate that when estuarine discharge increases, net plume mixing decreases in a rotating environment but increases …

Factors Associated With Anaplasma Spp. Seroprevalence Among Dogs In The United States, Christopher S. Mcmahan, Dongmei Wang, Melissa J. Beall, Dwight D. Bowman, Susan E. Little, Patrick O. Pithua, Julia L. Sharp, Roger W. Stich, Michael J. Yabsley, Robert B. Lund

Publications

Background

Dogs in the United States are hosts to a diverse range of ticks and tick-borne pathogens, including A. phagocytophilum, an important emerging canine and human pathogen. Previously, a Companion Animal Parasite Council (CAPC)-sponsored workshop proposed factors purported to be associated with the infection risk for tick-transmitted pathogens in dogs in the United States, including climate conditions, socioeconomic characteristics, local topography, and vector distribution.

Methods

Approximately four million test results from routine veterinary diagnostic tests from 2011–2013, which were collected on a county level across the contiguous United States, are statistically analyzed with the proposed factors via logistic regression …

Modeling Spatiotemporal Variability Of The Bioclimate Envelope Of Homarus Americanus In The Coastal Waters Of Maine And New Hampshire, Kisei Tananka, Yong Chen

Publications

A bioclimate envelope model was developed to evaluate the potential impacts of climate variability on American lobster (Homarus americanus). Bioclimate envelopes were defined by season-, sex-, and stage- specific Habitat Suitability Indices (HSI) based on (1) bottom temperature, (2) bottom salinity, and (3) depth. The species’ association to each of these three environmental attributes was expressed using Suitability Indices (SIs) calibrated by standardized lobster abundance derived from 14 years of fishery independent survey. A regional ocean model (Finite-Volume Community Ocean Model) was integrated with the HSI to hindcast spatiotemporal variability of bioclimate envelopes for American lobster in coastal waters of …

Why Rhetoric Matters For Ecology, Caroline Druschke, Bridie Mcgreavy

Publications

Increasingly, scientists and funding agencies such as the US National Science Foundation are recognizing the need for better science communication and more effective broader impacts activities. Compelled to make research more relevant to public stakeholders and policy makers, researchers look for ways to gain the necessary skillset to move their science from the field and laboratory into public forums. We suggest that the ancient discipline of rhetoric provides a useful – and underutilized – path forward. Building from the fundamental connections between ecology and rhetoric and drawing from practical examples at the intersection of these two fields, we demonstrate how …

Preservation Of Three-Dimensional Anatomy In Phosphatized Fossil Arthropods Enriches Evolutionary Inference, Achim H. Schwermann, Tomy Dos Santos Rolo, Michael S. Caterino, Gunter Bechly, Heiko Schmied, Tilo Baumbach, Thomas Van De Kamp

Publications

External and internal morphological characters of extant and fossil organisms are crucial to establishing their systematic position, ecological role and evolutionary trends. The lack of internal characters and soft-tissue preservation in many arthropod fossils, however, impedes comprehensive phylogenetic analyses and species descriptions according to taxonomic standards for Recent organisms. We found well-preserved three-dimensional anatomy in mineralized arthropods from Paleogene fissure fillings and demonstrate the value of these fossils by utilizing digitally reconstructed anatomical structure of a hister beetle. The new anatomical data facilitate a refinement of the species diagnosis and allowed us to reject a previous hypothesis of close phylogenetic …

A Revision Of Megalocraerus Lewis, 1902 (Coleoptera, Histeridae: Exosternini), Michael S. Caterino, Alexey K. Tishechkin

Publications

The formely monotypic Neotropical genus Megalocraerus Lewis is revised to include five species, known from southeastern Brazil to Costa Rica: M. rubricatus Lewis, M. mandibularis sp. n., M. chico sp. n., M. madrededios sp. n., and M. tiputini sp. n. We describe the species, map their distributions, and provide a key for their identification. Their subcylindrical body form and emarginate mesosternum have previously hindered placement to tribe, although their curent assignment to Exosternini now appears well supported by morphological evidence. Nothing is known of the natural history of the species.

Design And Commissioning Of A Community Scale Solar Powered Membrane-Based Water Purification System In Haiti, Shavin Pinto, Yung Wong, Kyle Fennesy, Yan Tang, Marc Compere

Publications

This paper presents the design and commissioning of a solar powered water purification system at the Ryan Epps Home for Children (REHC) in Michaud, Haiti. This system supplies clean drinking water to the 200 children who live and go to school at REHC and also to the community in the form of a micro-business. This micro-business is the mechanism for income generation for sustainable system operation. The purifier uses a three stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane …