Biology Commons^™

Genetic Basis For Rhizobium Etli Ce3 O-Antigen O-Methylated Residues That Vary According To Growth Conditions, Kristylea J. Ojeda, Jodie M. Box, K. Dale Noel

Biological Sciences Faculty Research and Publications

The Rhizobium etli CE3 O antigen is a fixed-length heteropolymer with O methylation being the predominant type of sugar modification. There are two O-methylated residues that occur, on average, once per complete O antigen: a multiply O-methylated terminal fucose and 2-O methylation of a fucose residue within a repeating unit. The amount of the methylated terminal fucose decreases and the amount of 2-O-methylfucose increases when bacteria are grown in the presence of the host plant, Phaseolus vulgaris, or its seed exudates. Insertion mutagenesis was used to identify open reading frames required for the presence of these O-methylated …

Chlamydomonas Mutants Display Reversible Deficiencies In Flagellar Beating And Axonemal Assembly, Mei Wei, Priyanka Sivadas, Heather A. Owen, David R. Mitchell, Pinfen Yang

Biological Sciences Faculty Research and Publications

Axonemal complexes in flagella are largely prepackaged in the cell body. As such, one mutation often results in the absence of the co-assembled components and permanent motility deficiencies. For example, a Chlamydomonas mutant defective in RSP4 in the radial spoke (RS), which is critical for bend propagation, has paralyzed flagella that also lack the paralogue RSP6 and three additional RS proteins. Intriguingly, recent studies showed that several mutant strains contain a mixed population of swimmers and paralyzed cells despite their identical genetic background. Here we report a cause underlying these variations. Two new mutants lacking RSP6 swim processively and other …

A Framework For Automated Enrichment Of Functionally Significant Inverted Repeats In Whole Genomes, Cyriac Kandoth, Fikret ErçAl, Ronald L. Frank

Computer Science Faculty Research & Creative Works

Background: RNA transcripts from genomic sequences showing dyad symmetry typically adopt hairpin-like, cloverleaf, or similar structures that act as recognition sites for proteins. Such structures often are the precursors of non-coding RNA (ncRNA) sequences like microRNA (miRNA) and small-interfering RNA (siRNA) that have recently garnered more functional significance than in the past. Genomic DNA contains hundreds of thousands of such inverted repeats (IRs) with varying degrees of symmetry. But by collecting statistically significant information from a known set of ncRNA, we can sort these IRs into those that are likely to be functional.

Results: A novel method was developed to …

The Scale Of Population Structure In Arabidopsis Thaliana, Alexander Platt, Matthew Horton, Yu S. Huang, Yan Li, Alison E. Anastasio, Ni Wayan Mulyati, Jon Agren, Oliver Bossdorf, Diane Byers, Kathleen Donohue, Megan Dunning, Eric B. Holub, Andrew Hudson, Valerie Le Corre, Olivier Loudet, Fabrice Roux, Norman Warthmann, Detlef Weigel, Luz Rivero, Randy Scholl, Magnus Nordborg, Joy Bergelson, Justin O. Borevitz

Faculty Publications – Biological Sciences

The population structure of an organism reflects its evolutionary history and influences its evolutionary trajectory. It constrains the combination of genetic diversity and reveals patterns of past gene flow. Understanding it is a prerequisite for detecting genomic regions under selection, predicting the effect of population disturbances, or modeling gene flow. This paper examines the detailed global population structure of Arabidopsis thaliana. Using a set of 5,707 plants collected from around the globe and genotyped at 149 SNPs, we show that while A. thaliana as a species self-fertilizes 97% of the time, there is considerable variation among local groups. This level …

Selection Ratios On Community Aggregated Traits To Estimate Ecological Filters Imposed On Species By Sites, Nathanael I. Lichti, Michael T. Murphy

Biology Faculty Publications and Presentations

Variation in community structure is mediated by interactions between species traits and a site's environmental characteristics. Previously, data on community composition at sites has been employed to correlate trait and environmental variables (e.g., RLQ analysis) and to predict community-level expression of quantitative traits (i.e., community aggregated traits). Here, we demonstrate that the selection ratio, a method originating in animal resource selection studies, can estimate the ecological filters that site conditions impose on species traits by combining observed community aggregated traits with null models of species availability. This flexible, nonparametric approach expresses the filter at each site as a probability density …

Range Extension Parameters Of The Opportunistic Bivalve Corbicula Fluminea (Müller, 1774) In New Jersey, Katie Elizabeth Vazquez

Theses, Dissertations and Culminating Projects

The invasive freshwater bivalve Corbicula fluminea has gained notoriety as a macro-fouler of industrial waterways across the United States. Little is known about the specific habitat requirements that contribute to its successful colonization of riverine systems. Small, often immature clams (shell length <14 mm) passively drift downstream. Settlement in unsuitable habitat can limit burrowing, growth and reproduction, and lead to juvenile mortality. Settlement in suitable habitat however can result in population densities in excess of 10,000 ind./m . Sampling was conducted in diverse Northern New Jersey waterways between May and mid-October 2008 to assess the habitat conditions conducive to establishment of new populations. Within these sites there was a significant correlation between clam density and both dissolved oxygen level and Ambient Biological Monitoring Network EPT scores. There was no correlation between clam density and dominant grain size, substratum organic content or turbidity. It appears stochastic events largely governed the dispersal and settlement of juvenile and small mature Asian clams while microhabitat conditions can be associated with population density. Live specimens of C. fluminea were collected at 8 sites half of which appear to house stable reproducing populations of C. fluminea. The remaining sites could represent interim “stops” likely containing specimens that entered as a result of downstream drift. Anthropogenic disturbance regimes in New Jersey waterways may contribute to the successful invasion by the Asian clam. An understanding of the habitat and physicochemical characteristics associated with the spread of juvenile C. fluminea is crucial to predictive modeling of dispersal patterns.

Sperm Morphometrics In The Diamond-Backed Watersnake, Nerodia Rhombifer Hallowell, With Reference To Possible Implications On Sperm Competition, Jonathan Wade Stanley

Student Theses and Dissertations

A total of 46 male Diamond-backed Watersnakes, Nerodia rhombifer Hallowell were collected from Mallard Lake in Mississippi County, Arkansas and a catfish farm in Desha County, Arkansas to determine effects that the farm may have on sperm morphometrics in this species. Snout-vent lengths (SVL) were recorded and blood samples were collected for hematocrit (Hct) determination. Sperm were collected, viewed by scanning electron microscopy, and measured for overall length, head length, and tail length. Snakes from the fish farm had significantly longer SVL than did snakes from Mallard Lake. No correlation was found between Hct values and SVL, but differences were …

A New Species Of Gekko (Squamata: Gekkonidae) From Tà Kóu Nature Reserve, Binh Thuan Province, Southern Vietnam, Van Tri Ngo, Tony Gamble

Biological Sciences Faculty Research and Publications

A new species of Gekko Laurenti is described from Ta Kou Mountain, an isolated granitic peak in Ta Kou Nature Reserve, Ham Thuan Nam district, Binh Thuan province, southern Vietnam. The species is distinguished from its congeners by its moderate size, with snout to vent length (SVL) reaching a maximum 107.0 mm; dorsal pattern of 5–8 white vertebral blotches between the nape and sacrum and 6–8 pairs of short white bars on the flanks; 11–14 precloacal pores in males; 14–17 longitudinal rows of smooth dorsal tubercles; and 18–20 broad lamellae beneath the fourth toe. Gekko takouensis sp. nov. is the …

Estrogen Receptor-Alpha In The Bed Nucleus Of The Stria Terminalis Regulates Social Affiliation In Male Prairie Voles (Microtus Ochrogaster), Kelly Lei, Bruce S. Cushing, Sergei Musatov, Sonoko Ogawa, Kristin M. Kramer

Biology Faculty Research

Estrogen receptor alpha (ER alpha) typically masculinizes male behavior, while low levels of ER alpha in the medial amygdala (MeA) and the bed nucleus of the stria terminalis (BST) are associated with high levels of male prosocial behavior. In the males of the highly social prairie vole (Microtus ochrogaster), increasing ER alpha in the MeA inhibited the expression of spontaneous alloparental behavior and produced a preference for novel females. To test for the effects of increased ER alpha in the BST, a viral vector was used to enhance ER alpha expression in the BST of adult male prairie voles. Following …

The Identification Of Rana Ocellata Linnaeus, 1758. Nomenclatural Impact On The Species Currently Known As Leptodactylus Ocellatus (Leptodactylidae) And Osteopilus Brunneus (Gosse, 1851) (Hylidae), Esteban O. Lavilla, José A. Langone, Ulisses Caramaschi, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

The usage of the name Rana ocellata Linnaeus, 1758, is plagued by misidentifications and misinterpretations. After an exhaustive bibliographic review, we conclude that the Linnaeus 1758 name refers to Osteopilus brunneus (Gosse, 1851) from Jamaica, while the taxon currently known as Leptodactylus ocellatus corresponds to Rana latrans Steffen, 1815. Herein, we designate and provide descriptions of the neotypes of Leptodactylus latrans (Steffen, 1815), revalidated, new combination, and Osteopilus ocellatus (Linnaeus, 1758), new combination, as a senior synonym of Osteopilus brunneus (Gosse, 1851).

The Role Of Litter Quality Feedbacks In Terrestrial Nitrogen And Phosphorus Cycling, Johannes M.H. Knops, David A. Wedin, Shahid Naeem

School of Biological Sciences: Faculty Publications

Many studies in ecosystem ecology argue for strong control of litter quality over nitrogen (N) cycling. We developed a model for temperate grasslands to test the importance of litter quality in decomposition for N and phosphorus (P) cycling based on the following premises. First, terrestrial N and P cycling differ fundamentally because N is a structural component of the soil organic matter (SOM), whereas P is not. Secondly, SOM has a much lower C:N ratio than litter inputs. Thirdly, litter decomposition follows an exponential decay with 20% of the original litter mass turning into SOM. Fourth, litter N concentration shows …

Systemic Administration Of Antiretrovirals Prior To Exposure Prevents Rectal And Intravenous Hiv-1 Transmission In Humanized Blt Mice, Paul W. Denton, John F. Krisko, Daniel A. Powell, Melissa Mathias, Youn Tae Kwak, Francisco Martinez-Torres, Wei Zou, Deborah A. Payne, Jacob D. Estes, J. Victor Garcia

Biology Faculty Publications

Successful antiretroviral pre-exposure prophylaxis (PrEP) for mucosal and intravenous HIV-1 transmission could reduce new infections among targeted high-risk populations including discordant couples, injection drug users, high-risk women and men who have sex with men. Targeted antiretroviral PrEP could be particularly effective at slowing the spread of HIV-1 if a single antiretroviral combination were found to be broadly protective across multiple routes of transmission. Therefore, we designed our in vivo preclinical study to systematically investigate whether rectal and intravenous HIV-1 transmission can be blocked by antiretrovirals administered systemically prior to HIV-1 exposure. We performed these studies using a highly relevant in …

Expression Profiles During Dedifferentiation In Newt Lens Regeneration Revealed By Expressed Sequence Tags, Nobuyasu Maki, John Martinsou, Osamu Nishimura, Hiroshi Tarui, Jaroslaw Meller, Panagiotis A. Tsonis, Kiyokazu Agata

Biology Faculty Publications

Purpose: The adult newt can regenerate lens from pigmented epithelial cells (PECs) of the dorsal iris via dedifferentiation. The purpose of this research is to obtain sequence resources for a newt lens regeneration study and to obtain insights of dedifferentiation at the molecular level.

Layered Organization In The Coastal Ocean: An Introduction To Planktonic Thin Layers And The Loco Project, James M. Sullivan, D. Van Holliday, Malcolm Mcfarland, Margaret A. Mcmanus, Olivia M. Cheriton, Kelly J. Benoit-Bird, Louis Goodman, Zhankun Wang, John P. Ryan, Mark Stacey, Charles Greenlaw, Mark A. Moline

Biological Sciences

No abstract provided.

Integrated Measurements Of Acoustical And Optical Thin Layers Ii: Horizontal Length Scales, Mark A. Moline, Kelly J. Benoit-Bird, Ian C. Robbins, Maddie Schroth-Miller, Chad M. Waluk, Brian Zelenke

Biological Sciences

The degree of layered organization of planktonic organisms in coastal systems impacts trophic interactions, the vertical availability of nutrients, and many biological rate processes. While there is reasonable characterization of the vertical structure of these phenomena, the extent and horizontal length scale of variation has rarely been addressed. Here we extend the examination of the vertical scale in the first paper of the series to the horizontal scale with combined shipboard acoustic measurements and bio-optic measurements taken on an autonomous underwater vehicle. Measurements were made in Monterey Bay, CA from 2002 to 2008 for the bio-optical parameters and during 2006 …

Integrated Measurements Of Acoustical And Optical Thin Layers I: Vertical Scales Of Association, Kelly J. Benoit-Bird, Mark A. Moline, Chad M. Waluk, Ian C. Robbins

Biological Sciences

This study combined measurements from multiple platforms with acoustic instruments on moorings and on a ship and optics on a profiler and an autonomous underwater vehicle (AUV) to examine the relationships between fluorescent, bioluminescent, and acoustically scattering layers in Monterey Bay during nighttime hours in July and August of 2006 and May of 2008. We identified thin bioluminescent layers that were strongly correlated with acoustic scattering at the same depth but were part of vertically broad acoustic features, suggesting layers of unique composition inside larger biomass features. These compositional thin layers nested inside larger biomass features may be a common …

Effects Of Small Increases In Corticosterone Levels On Morphology, Immune Function, And Feather Development, Michael W. Butler, Lynda L. Leppert, Alfred M. Dufty Jr.

Biology Faculty Publications and Presentations

Stressors encountered during avian development may affect an individual’s phenotype, including immunocompetence, growth, and feather quality. We examined effects of simulated chronic low-level stress on American kestrel (Falco sparverius) nestlings. Continuous release of corticosterone, a hormone involved in the stress response, can model chronic stress in birds. We implanted 13-d-old males with either corticosterone-filled implants or shams and measured their growth, immune function, and feather coloration.We found no significant differences between groups at the end of the weeklong exposure period in morphometrics (mass, tarsus, wing length, and asymmetry), immunocompetence (cutaneous immunity, heterophil/lymphocyte ratio, and humoral immunity), or feather …

A Search For Genetic Modifiers Responsible For Congenital Heart Disease Variability In The Presence Of Nkx2-5 Haploinsufficiency, Julia Brandeis Winston Honold

All Theses and Dissertations (ETDs)

While a clear heritable risk has been observed for congenital heart disease, there is considerable variation in penetrance and presentation likely due to multiple genetic and environmental risk factors. To identify causative factors and interactions responsible for variability in heart development, greater than 4,200 hearts from Nkx2-5 heterozygous knockout mice have been collected and examined. Nkx2-5+/- mice in the inbred strain background C57Bl/6 frequently have atrial and ventricular septal defects. The incidences are substantially reduced in the Nkx2-5+/- progeny of first-generation: F1) outcrosses to the strains FVB/N or A/J. Defects recur in the second generation: F2) of the F1xF1 intercross …

Leptodactylus Cunicularius, W. R. Heyer, Miriam M. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus cunicularius are moderately small. The head is longer than wide and the hind limbs are long (Table 1; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are internal, not externally expanded. The snout is protruding, not sexually dimorphic. Male forearms are not hypertrophied and males lack asperities on the thumbs and chest. The dorsum is variegated with small, often confluent, spots and blotches. There is a very thin interrupted mid-dorsal light stripe (pinstripe). Usually, there is a noticeable light, irregular, elongate, mid-dorsal blotch in the scapular region. The …

Leptodactylus Syphax, W. R. Heyer, Miriam M. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus syphax are moderately sized (males 58-83 mm, females 70-90 mm SVL). The head is about as long as wide, but usually is just wider than long. The hind limbs are moderately short (Table 1; Heyar and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are laterally expanded, tan, and not darker than the adjacent throat. The male snout is not spatulate, the snout profile is rounded to obtuse in both sexes. Male arms are hypertrophied during the breeding season in sexually active males. The male thumb has two large, …

Genome Sequence Of The Palaeopolyploid Soybean, Jeremy Schmutz, Steven B. Cannon, Jessica Schlueter, Jianxin Ma, Therese Mitros, William Nelson, David L. Hyten, Qijian Song, Jay J. Thelen, Jianlin Cheng, Dong Xu, Uffe Hellsten, Gregory D. May, Yeisoo Yu, Tetsuya Sakurai, Taishi Umezawa, Madan K. Bhattacharyya, Devinder Sandhu, Babu Valliyodan, Erika Lindquist, Myron Peto, David Grant, Shengqiang Shu, David Goodstein, Kerrie Barry, Montona Futrell-Griggs, Brian Abernathy, Jianchang Du, Zhixi Tian, Liucun Zhu, Navdeep Gill, Trupti Joshi, Marc Libault, Anand Sethuraman, Xue-Cheng Zhang, Kazuo Shinozaki, Henry T. Nguyen, Rod A. Wing, Perry Cregan, James Specht, Jane Grimwood, Dan Rokhsar, Gary Stacey, Randy C. Shoemaker, Scott A. Jackson

Biology Faculty Articles

Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70% more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78% of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but …

Investigating The Activity Spectrum For Ring-Substituted 8-Hydroxyquinolines, James Carroll, Jim O'Mahony, Aidan Coffey, Et. Al.

Department of Biological Sciences Publications

In this study, a series of fourteen ring-substituted 8-hydroxyquinoline derivatives were prepared. The synthesis procedures are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains and against eight fungal strains. Several compounds showed biological activity comparable with or higher than the standards isoniazid or fluconazole. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed.

Domestic Exotics And The Perception Of Invasibility, Qinfeng Guo, Robert Ricklefs

Biology Department Faculty Works

Susceptibility of an area to invasion by exotic species is often judged by the fraction of introduced species in the local biota. However, the degree of invasion, particularly in mainland areas, has often been underestimated because of the exclusion of ‘domestic exotics’ (those introduced to internal units from within the national border) in calculations. Because all introduced species on islands are considered as exotics, this contributes to the perception that islands are more susceptible to invasion than are continental regions. Here, we determine the contribution of domestic exotic species to the degree of invasion (exotic fraction) in mainland areas. We …

Impacts Of An Orange Oil Solvent And Stickem On The Detection Of Xylella Fastidiosa Dna In Glassy-Winged Sharpshooters, Homalodisca Vitripennis (Hemiptera: Cicadellidae), Patrick Marshall, Daymon Hail, Forrest Mitchell, Blake Bextine

Biology Faculty Publications and Presentations

Xylella fastidiosa is a plant pathogenic bacterium that causes many economically important agricultural diseases and is transmitted by the glassy-winged sharpshooter, Homalodisca vitripennis (Hemiptera: Cicadellidae). Efficient detection of X. fastidiosa in field collected H. vitripennis in an area-wide management program can contribute to risk assessment associated with insect presence in vineyards. Prior to conducting molecular assays for detection of X. fastidiosa in individual insects, H. vitripennis must be removed from yellow sticky traps with a solvent such as orange oil. In this study, we determined the effect of orange oil concentration on extraction of individual H. vitripennis following trap removal …

Tuning A Nose To Forage: Evidence For Olfactory Learning In A Procellariiform Seabird Chicks, Gregory B. Cunningham, Gabrielle A. Nevitt

Biology Faculty/Staff Publications

Burrow nesting procellariiform seabirds use olfactory cues for both foraging and nest recognition. As chicks, burrow nesters develop in the dark, but are exposed to both prey-related and individual-specific scents through contact with their parents. This exposure suggests that chicks may have the opportunity to learn odours while still in the nest. In this study, we examined whether exposure to odourants during development might influence olfactory search behaviour expressed later in life. To test this idea, we exposed eggs of thin-billed prions Pachyptila belcheri to a rosy-scented novel odour (phenyl ethyl alcohol, PEA) or a control (water) just before hatching; …

Insights From Comparative Analyses Of Aging In Birds And Mammals, Robert Ricklefs

Biology Department Faculty Works

Many laboratory models used in aging research are inappropriate for understanding senescence in mammals, including humans, because of fundamental differences in life history, maintenance in artificial environments, and selection for early aging and high reproductive rate. Comparative studies of senescence in birds and mammals reveal a broad range in rates of aging among a variety of taxa with similar physiology and patterns of development. These comparisons suggest that senescence is a shared property of all vertebrates with determinate growth, that the rate of senescence has been modified by evolution in response to the potential life span allowed by extrinsic mortality …

Genome Sequence Of The Pea Aphid Acyrthosiphon Pisum, The International Aphid Genomics Consortium

Biology Articles and Papers

Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. …

A Habitat Model For The Detection Of Two-Lined Salamanders At C. F. Phelps Wildlife Management Area, Fauquier And Culpeper Counties, Virginia, Jay Mcghee, Michael D. Killian

Virginia Journal of Science

Aquatic salamanders represent an important component of Virginia river watersheds, but despite potential declines, few specifics are known about their habitat preferences. We surveyed the habitats of the northern two-lined salamander and collected data on an array of habitat variables associated with the species. We used a logistic regression analysis to develop a model predicting its presence or absence for a given 50m-transect. Our final model incorporated the variation in stream depth and direction of stream flow and accounted for 25% of the variation in our data. We conclude that stream depth variation is an important feature of salamander habitat …

Functional Feeding Groups, Species Richness, And Spatial Distributions Of Fishes In Rocky And Sandy Beach Habitats Of St. John, U.S. Virgin Islands, Eugene G. Maurakis, George E. Maurakis, Demetri E. Maurakis

Virginia Journal of Science

Objectives were to identify and compare fish species richness, functional feeding group richness and diversity, and delineate distributions of fishes at rocky and sandy beach habitats at St. John, U.S. Virgin Islands. Visual observations using snorkel and mask were made at 3-m intervals seaward from shore during daylight hours. A total of 69 taxa (67 species) representing 33 families of fishes were observed. Total (53) and average fish species richness (32.7) at rocky beach habitats were greater than those (total=43; average=24.3) at sandy beach habitats. Twelve functional feeding groups were identified (diurnal planktivores, excavators/eroders, macroalgae browsers, macrocarnivores, mobile benthic scrapers, …

Ecological Opportunity And The Origin Of Adaptive Radiations, J. B. Yoder, E. Clancey, S. Des Roches, J. M. Eastman, L. Gentry, W. Godsoe, T. J. Hagey, D. Jochimsen, B. P. Oswald, J. Robertson, B. Sarver, J. J. Schenk, S. F. Spear, L. J. Harmon

Biology

Ecological opportunity – through entry into a new environment, the origin of a key innovation or extinction of antagonists – is widely thought to link ecological population dynamics to evolutionary diversification. The population-level processes arising from ecological opportunity are well documented under the concept of ecological release. However, there is little consensus as to how these processes promote phenotypic diversification, rapid speciation and adaptive radiation. We propose that ecological opportunity could promote adaptive radiation by generating specific changes to the selective regimes acting on natural populations, both by relaxing effective stabilizing selection and by creating conditions that ultimately generate diversifying …