Life Sciences Commons^™

Influence Of The Hydrodynamic Environment On Quorum Sensing In Pseudomonas Aeruginosa Biofilms, Jeffrey J. Margolis, Mary Jo Kirisits, Boloroo L. Purevdorj-Gage, Benjamin Vaughan, David L. Chopp, Paul Stoodley, Matthew R. Parsek

Jeffrey Margolis

Identification Of Synechococcus Sp. Iu 625 Metallothionein Gene And Its Evolutionary Relationship To The Metallothionein Gene Of Other Cyanobacteria, Tin-Chun Chu, Lee Lee, John Gaynor, Quinn Vega, Bonnie Lustigman, Shankar Srinivasan

Tin-Chun Chu, Ph.D.

No abstract provided.

Organisms Associated With Bacterial Vaginosis In Nigerian Women As Determined By Pcr-Dgge And 16s Rrna Gene Sequence, Kingsley Anukam, Gregor Reid

Kingsley C Anukam

Background: Bacterial vaginosis (BV) is a condition with diverse etiology. This condition predisposes women to increased susceptibility to sexually transmitted diseases, including human immunodeficiency virus (HIV) infections and preterm birth. The diagnostic methods currently adopted in the evaluation of patient samples for BV are arguably Amsel criteria, and Nugent score that require microscopy and expert interpretation. These two methods are still subjective. Objective: The objective of this study was to determine the organisms present in the vagina of 34 HIV negative Nigerian women diagnosed as having bacterial vaginosis by using molecular techniques. Methods: The vaginal samples were subjected to DNA …

Molecular Genetics And Genomic Analysis Of Scytonemin Biosynthesis In Nostoc Punctiforme Atcc 29133, Tanya Soule, Valerie Stout, Wesley Swingley, J C. Meeks, Ferran Garcia-Pichel

Tanya Soule

The indole-alkaloid scytonemin is the most common and widespread sunscreen among cyanobacteria. Previous research has focused on its nature, distribution, ecology, physiology, and biochemistry, but its molecular genetics have not been explored. In this study, a scytonemin-deficient mutant of the cyanobacterium Nostoc punctiforme ATCC 29133 was obtained by random transposon insertion into open reading frame NpR1273. The absence of scytonemin under conditions of induction by UV irradiation was the single phenotypic difference detected in a comparative analysis of the wild type and the mutant. A cause-effect relationship between the phenotype and the mutation in NpR1273 was demonstrated by constructing a …

In Vivo Negative Selection Screen Identifies Genes Required For Francisella Virulence, David S. Weiss, Anna Brotcke, Thomas Henry, Jeffrey J. Margolis, Kaman Chan, Denise M. Monack

Jeffrey Margolis

Genetic Diversity And Potential Function Of Microbial Symbionts Associated With Newly Discovered Species Of Osedax Polychaete Worms, Shana K. Goffredi, Shannon B. Johnson, Robert C. Vrijenhoek

Shana Goffredi

We investigated the genetic diversity of symbiotic bacteria associated with two newly discovered species of Osedax from Monterey Canyon, CA, at 1,017-m (Osedax Monterey Bay sp. 3 “rosy” [Osedax sp. MB3]) and 381-m (Osedax Monterey Bay sp. 4 “yellow collar”) depths. Quantitative PCR and clone libraries of 16S rRNA gene sequences identified differences in the compositions and abundances of bacterial phylotypes associated with the newly discovered host species and permitted comparisons between adult Osedax frankpressi and juveniles that had recently colonized whalebones implanted at 2,891 m. The newly discovered Osedax species hosted Oceanospirillales symbionts that are related to Gammaproteobacteria associated …

Evolution, Jonathan Eisen

Jonathan A. Eisen Ph.D.

No abstract provided.

The Role Of Protein Glycosylation In The Virulence Of The Gastric Pathogens Helicobacter Pylori And Campylobacter Jejuni, Alexandra Merkx-Jacques, C. Creuzenet

Alexandra Merkx-Jacques

H. pylori and C. jejuni are Gram-negative gastro-intestinal pathogens whose virulence is highly affected by protein glycosylation. The former causes gastric ulcers and cancer, while the latter causes enteritis and neurological disorders. Due to emerging drug-resistant strains, new treatments are needed.

In both bacteria, the flagellins are essential virulence factors glycosylated by pseudaminic acid (PA). We have identified and disrupted genes required for PA synthesis in both bacteria, and shown that this affects flagellin production. Further analysis and glycoprotein staining revealed that in H. pylori, the PA pathway is necessary for the glycosylation of proteins other than flagellins and …

Genetics And Biochemistry Of Protein Glycosylation In Campylobacter Jejuni, Alexandra Merkx-Jacques, S. Vijayakumar, M. Demendi, D. Ratnayake, C. Dozois, C. Creuzenet

Alexandra Merkx-Jacques

BACKGROUND: C. jejuni produces numerous glycoproteins, including flagellins, which are important for virulence. The flagellins harbour pseudaminic acid (PA) whereas other glycoproteins harbour diacetamidobacillosamine (DAB). We are investigating the genetics and biochemistry of protein glycosylation in C. jejuni to identify the enzymes involved, and determine their activity and roles in virulence. We focused on two homologous pathways comprising each a putative dehydratase, aminotransferase and acetyltransferase, namely {Cj1293, Cj1294 and Cj1298} and {Cj1120c, Cj1121c and Cj1123c}.

METHODS: All enzymes were overexpressed and purified before monitoring their activity by capillary electrophoresis. The cj1121c and cj1294 genes were disrupted by a chloramphenicol resistance …

Runx2 Is Essential For Larval Hyobranchial Cartilage Formation In Xenopus Laevis, Ryan Kerney, Joshua Gross, James Hanken

Ryan Kerney

The vertebrate transcription factor protein Runx2 is regarded as a “master regulator” of bone formation due to the dramatic loss of the osseous skeleton in the mouse homozygous knockout. However, Runx2 mRNA also is expressed in the pre-hypertrophic cartilaginous skeleton of the mouse and chicken, where its developmental function is largely unknown. Several tiers of Runx2 regulation exist in the mouse, any of which may account for its seeming biological inactivity during early stages of skeletogenesis. Unlike mouse and chicken, zebrafish require Runx2 function in early cartilage differentiation. The present study reveals that the earlier functional role of Runx2 in …

Cranial Ontogeny In Philautus Silus (Anura: Ranidae: Rhacophorinae) Reveals Few Similarities With Other Direct-Developing Anurans, Ryan Kerney, Madhava Meegaskumbura, Kelum Manamendra-Arachchi, James Hanken

Ryan Kerney

Direct development has evolved in rhaco- phorine frogs independently from other anuran lineages, thereby offering an opportunity to assess features associ- ated with this derived life history. Using a developmen- tal series of the direct-developing Philautus silus (Ranidae: Rhacophorinae) from Sri Lanka, we examine features of cranial morphology that are part of a suite of adaptations that facilitate feeding in free-living tadpoles, but have been changed or lost in other direct-developing lineages. Larval-specific upper jaw cartilages, which are absent from many non-rhacophorine direct-developing species (such as Eleutherodactylus coqui), develop in embryos of P. silus. Similarly, lower jaw cartilages ini- tially …

In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant

Donald J. Kochan

Significant research has been conducted into the utilization of geothermal resources as a ‘green’ energy source. However, minimal research has been conducted into geothermal resource utilization and depletion impacts on thermophile biodiversity. Thermophiles are organisms which have adapted over millions of year to extreme temperature and chemical compositions and exist in hot springs and other geothermal resources. Their ability to withstand high temperatures makes them invaluable to scientific and medical research. Current federal and California case law classify geothermal resources as a mineral, not a water resource. Acquisition of rights to develop a geothermal resource owned or reserved by the …