Life Sciences Commons^™

Patric: The Vbi Pathosystems Resource Integration Center, Gongxin Yu

Biology Faculty Publications and Presentations

The PathoSystems Resource Integration Center (PATRIC) is one of eight Bioinformatics Resource Centers (BRCs) funded by the National Institute of Allergy and Infection Diseases (NIAID) to create a data and analysis resource for selected NIAID priority pathogens, specifically proteobacteria of the genera Brucella, Rickettsia and Coxiella, and corona-, caliciand lyssaviruses and viruses associated with hepatitis A and E. The goal of the project is to provide a comprehensive bioinformatics resource for these pathogens, including consistently annotated genome, proteome and metabolic pathway data to facilitate research into counter-measures, including drugs, vaccines and diagnostics. The project’s curation strategy has three …

Capraria Mexicana (Scrophulariaceae) In Cameron County, Texas: Rediscovered In The United States, Alfred Richardson, Ken King

Biology Faculty Publications and Presentations

Two new sites are reported for Capraria mexicana (Scrophulariaceae) in the United States.

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Se reportan dos nuevos sitios para Capraria mexicana (Scrophulariaceae) en los Estados Unidos

Isolation Of A Ubiquitous Obligate Thermoacidophilic Archaeon From Deep-Sea Hydrothermal Vents, Anna-Louise Reysenbach, Yitai Liu, Amy B. Banta, Terry J. Beveridge, Julie D. Kirshtein, Stefan Schouten, Margaret K. Tivey, Karen L. Von Damm, Mary A. Voytek

Biology Faculty Publications and Presentations

Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide–sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2) Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75 °C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents.

Mechanism Of Enhanced Activity Of Liposome-Entrapped Aminoglycosides Against Resistant Strains Of Pseudomonas Aeruginosa, Clement Mugabe, Majed Halwani, Ali Azghani, Robert M. Lafrenie, Abdelwahab Omri

Biology Faculty Publications and Presentations

Pseudomonas aeruginosa is inherently resistant to most conventional antibiotics. The mechanism of resistance of this bacterium is mainly associated with the low permeability of its outer membrane to these agents. We sought to assess the bactericidal efficacy of liposome-entrapped aminoglycosides against resistant clinical strains of P. aeruginosa and to define the mechanism of liposome-bacterium interactions. Aminoglycosides were incorporated into liposomes, and the bactericidal efficacies of both free and liposomal drugs were evaluated. To define the mechanism of liposome-bacterium interactions, transmission electron microscopy (TEM), flow cytometry, lipid mixing assay, and immunocytochemistry were employed. Encapsulation of aminoglycosides into liposomes significantly increased their …

Sex Determination Of Red-Tailed Hawks (Buteo Jamaicensis Calurus) Using Dna Analysis And Morphometrics, Kara C. Donohue, Alfred M. Dufty Jr.

Biology Faculty Publications and Presentations

Currently the sex of Red-tailed hawks (Buteo jamaicensis) cannot be determined by in-hand methods. Males and females do not differ in plumage and overlap in size. During migration, we collected feather samples and morphological measurements from birds at four sites in the Western United States. Sex was determined for individual birds using sex-specific DNA markers and Polymerase Chain Reaction was used to identify these DNA markers. Through Discriminant Function Analysis, we created equations for determining the sex of Red-tailed hawks using in-hand measurements based on the DNA-determined sexes. We formed two equations, one for adults, which was 98% …

Digging Mechanisms And Substrate Preferences Of Shovel Nosed Lobsters, Ibacus Peronii (Decapoda: Scyllaridae), Zen Faulkes

Biology Faculty Publications and Presentations

Digging is a distinct form of locomotion that poses different mechanical problems than other locomotor modes that are commonly used by crustaceans, e.g., walking, swimming. I examined the mechanisms of digging by shovel nosed lobsters (Ibacus peronii), which spend most of the day underneath sand. Ibacus peronii were videotaped while digging. Ibacus peronii use a “wedge” strategy to submerge into sand. An individual penetrates the sand with the walking legs, then extends the abdomen to push sand backwards, then flexes the abdomen while pushing backward with the legs, which slowly drives the body into the sand. This basic …

Cultivation Of Methanogens From Shallow Marine Sediments At Hydrate Ridge, Orego, Melissa Kendall, David R. Boone

Biology Faculty Publications and Presentations

Little is known about the methanogenic degradation of acetate, the fate of molecular hydrogen and formate or the ability of methanogens to grow and produce methane in cold, anoxic marine sediments. The microbes that produce methane were examined in permanently cold, anoxic marine sediments at Hydrate Ridge (44°35' N, 125°10' W, depth 800 m). Sediment samples (15 to 35 cm deep) were collected from areas of active methane ebullition or areas where methane hydrates occurred. The samples were diluted into enrichment medium with formate, acetate or trimethylamine as catabolic substrate. After 2 years of incubation at 4 °C to 15 …

Roles Of Intra-Fruit Oxygen And Carbon Dioxide In Controlling Pepper (Capsicum Annuum L.) Seed Development And Storage Reserve Deposition, J. Blasiak, Anxiu Kuang, Chakavak S. Farghangi, M. E. Musgrave

Biology Faculty Publications and Presentations

Seeds developing within a locular space inside hollow fruit experience chronic exposure to a unique gaseous environment. Using two pepper cultivars, `Triton' (sweet) and `PI 140367' (hot), we investigated how the development of seeds is affected by the gases surrounding them. The atmospheric composition of the seed environment was characterized during development by analysis of samples withdrawn from the fruit locule with a gas-tight syringe. As seed weight plateaued during development, the seed environment reached its lowest O2 concentration (19%) and highest CO2 concentration (3%). We experimentally manipulated the seed environment by passing different humidified gas mixtures through the fruit …

Loss Of Escape-Related Giant Neurons In A Spiny Lobster, Panulirus Argus, Sandra Y. Espinoza, Lana Breen, Nisha Varghese, Zen Faulkes

Biology Faculty Publications and Presentations

When attacked, many decapod crustaceans perform tailflips, which are triggered by a neural circuit that includes lateral giant interneurons, medial giant interneurons, and fast flexor motor giant neurons (MoGs). Slipper lobsters (Scyllaridae) lack these giant neurons, and it has been hypothesized that behavioral (e.g., digging) and morphological (e.g., flattening and armor) specializations in this group caused the loss of escape-related giant neurons. To test this hypothesis, we examined a species of spiny lobster, Panulirus argus. Spiny lobsters belong to the sister taxon of the scyllarids, but they have a more crayfish-like morphology than scyllarids and were predicted to have escape-related …