Life Sciences Commons^™

A Threat To New Zealand's Tuatara Heats Up, Kristine L. Grayson, Nicola J. Mitchell, Nicola J. Nelson

Biology Faculty Publications

No matter how many times we head to one of New Zealand's offshore islands, the feelings are always a mix of sheer awe at the beauty and biodiversity preserved in these special refuges and lingering nerves. Did we remember all the gear? Do we have enough food and water in case we get stuck? Can the helicopter land on the side of a cliff in these winds? These epic journeys are in pursuit of a lone remnant of the reptile evolutionary tree, with a unique ecology that has big implications under climate change.

Persistence And Stability Of Eastern Afromontane Forests: Evidence From Brevicipitid Frogs, Simon P. Loader, F. Sara Ceccarelli, Michele Menegon, Kim M. Howell, Roman Kassahun, Abebe A. Mengistu, Samy A. Saber, Fikirte Gebresenbet, Rafael O. De Sá, Et Al.

Biology Faculty Publications

Aim: The persistence and stability of habitats through time are considered predictors of high levels of biodiversity in some environments. Long-term habitat persistence and stability may explain the species-rich, endemic forest fauna and flora of the Eastern Afromontane Biodiversity Region (EABR). Using comple- mentary phylogenetic and biogeographical approaches, we examine evolution- ary patterns in EAR brevicipitid frogs. Using these data, we test whether brevicipitid history reflects patterns of long-term forest persistence and/or sta bility across the EABR.

Location: East Africa.

Methods: A dated phylogeny for brevicipitids was constructed using two nuclear and three mitochondrial markers. Alternative diversification modes were used …

Systematics Of The Neotropical Genus Leptodactylus Fitzinger, 1826 (Anura: Leptodactylidae): Phylogeny, The Relevance Of Non-Molecular Evidence, And Species Accounts, Rafael O. De Sá, Taran Grant, Arley Camargo, W. R. Heyer, María Laura Ponssa, Edward Stanley

Biology Faculty Publications

A phylogeny of the species-rich clade of the Neotropical frog genus Leptodactylus sensu stricto is presented on the basis of a total evidence analysis of molecular (mitochondrial and nuclear markers) and non-molecular (adult and larval morphological and behavioral characters) sampled from > 80% of the 75 currently recognized species. Our results support the monophyly of Leptodactylus sensu stricto, with Hydrolaetare placed as its sister group. The reciprocal monophyly of Hydrolaetare and Leptodactylus sensu stricto does not require that we consider Hydrolaetare as either a subgenus or synonym of Leptodactylus sensu lato. We recognize Leptodactylus sensu stricto, Hydrolaetare, Adenomera, and Lithodytes …

Lights And Larvae: Using Optogenetics To Teach Recombinant Dna And Neurobiology, John Titlow, Heidi Anderson, Robin L. Cooper

Biology Faculty Publications

Switching genes between organisms and controlling an animal’s brain using lasers may seem like science fiction, but with advancements in a technique called optogenetics, such experiments are now common in neuroscience research. Optogenetics combines recombinant DNA technology with a controlled light source to help researchers address biomedical questions in the life sciences. The technique has gained the most traction in neurobiology—the biology of the nervous system—where specific wavelengths of light are used to control or measure the activity of neurons in transgenic organisms (i.e., those with artificially inserted genes).

These optical recording and stimulation techniques are used in nervous system …

Us Epa Expert Workshop: Nutrient Enrichment Indicators In Streams, Michelle A. Baker, Candice Bauer, Max Bothwell, Don Charles, Betty Fetscher, Stuart Findlay, Terry Fleming, Steve Francoeur, Evelyn Gaiser, Jim Hagy, Anne Hershey, Lisa Huff, Ryan King, Tina Laidlaw, Mark Munn, Greg Pond, Steven Rier, Bob Sinsabaugh, A J. Smith, Nathan Smucker, Jan Stevenson, Mike Suplee

Biology Faculty Publications

No abstract provided.

Multiplex Ssr-Pcr Analysis Of Genetic Diversity And Redundancy In The Philippine Rice (Oryza Sativa L.) Germplasm Collection, Jamaica L. Delos Reyes, Vivian A. Panes, Dindo A. Tabanao, Gabriel O. Romero

Biology Faculty Publications

Rice germplasm conservation is vital to ensuring the availability of a rich gene pool for future varietal improvement programs. However, with limited resources for gene banking, there is a need to identify and prioritize unique accessions in the PhilRice gene bank for maximum resource utilization. A robust and unequivocal way to identify duplicates is through multiplex SSR-PCR DNA fingerprinting. The present study established the optimal concentrations and reaction conditions for the successful amplification of PCR products using a multiplex panel composed of rice simple sequence repeat (SSR) markers, namely RM312, RM316, RM514 and RM171. The panel was then used to …

Oh No! Something Is Eating My Coral Honeysuckle!, W. John Hayden

Biology Faculty Publications

Let’s imagine a situation that could happen in your own backyard. Suppose you have a healthy specimen of 2014’s Virginia Native Plant Society Wildflower of the Year, coral honeysuckle (Lonicera sempervirens). Suppose further that this plant rewards you every spring with a flush of flashy red flowers that you treasure all the more because they consistently bring hummingbirds to your yard. Now imagine that one fine morning you notice some little green caterpillars voraciously eating the leaves of your beloved coral honeysuckle. What do you do?

Major Alteration In Coxsackievirus B3 Genomic Rna Structure Distinguishes A Virulent Strain From An A Virulent Strain, Jerome Prusa, Johanna Missak, Jeff Kittrell, John J. Evans, William Tapprich

Biology Faculty Publications

Coxsackievirus B3 (CV-B3) is a cardiovirulent enterovirus that utilizes a 5′ untranslated region (5′UTR) to complete critical viral processes. Here, we directly compared the structure of a 5′UTR from a virulent strain with that of a naturally occurring avirulent strain. Using chemical probing analysis, we identified a structural difference between the two 5′UTRs in the highly substituted stem-loop II region (SLII). For the remainder of the 5′UTR, we observed conserved structure. Comparative sequence analysis of 170 closely related enteroviruses revealed that the SLII region lacks conservation. To investigate independent folding and function, two chimeric CV-B3 strains were created by exchanging …

Germination Season And Watering Regime, But Not Seed Morph, Affect Life History Traits In A Cold Desert Diaspore-Heteromorphic Annual, Juan J. Lu, Dun Y. Tan, Jerry M. Baskin, Carol C. Baskin

Biology Faculty Publications

Seed morph, abiotic conditions and time of germination can affect plant fitness, but few studies have tested their combined effects on plasticity of plant life history traits. Thus, we tested the hypothesis that seed morph, germination season and watering regime influence phenotypic expression of post-germination life history traits in the diaspore-heteromorphic cold desert winter annual/spring ephemeral Diptychocarpus strictus. The two seed morphs were sown in watered and non-watered plots in late summer, and plants derived from them were watered or not-watered throughout the study. Seed morph did not affect phenology, growth and morphology, survival, dry mass accumulation and allocation or …

Sox11 Is Required To Maintain Proper Levels Of Hedgehog Signaling During Vertebrate Ocular Morphogenesis, Lakshmi Pillai-Kastoori, Wen Wen, Stephen G. Wilson, Erin Strachan, Adriana Lo-Castro, Marco Fichera, Sebastiano A. Musumeci, Ordan J. Lehmann, Ann C. Morris

Biology Faculty Publications

Ocular coloboma is a sight-threatening malformation caused by failure of the choroid fissure to close during morphogenesis of the eye, and is frequently associated with additional anomalies, including microphthalmia and cataracts. Although Hedgehog signaling is known to play a critical role in choroid fissure closure, genetic regulation of this pathway remains poorly understood. Here, we show that the transcription factor Sox11 is required to maintain specific levels of Hedgehog signaling during ocular development. Sox11-deficient zebrafish embryos displayed delayed and abnormal lens formation, coloboma, and a specific reduction in rod photoreceptors, all of which could be rescued by treatment with the …

Aquastella Gen. Nov.: A New Genus Of Saprolegniaceous Oomycete Rotifer Parasites Related To Aphanomyces, With Unique Sporangial Outgrowths, Daniel P. Molloy, Sally L. Glockling, Clifford A. Siegfried, Gordon W. Beakes, Timothy Y. James, Sergey E. Mastitsky, Elizabeth S. Wurdak, Laure Giamberini, Michael J. Gaylo, Michael J. Nemeth

Biology Faculty Publications

The oomycete genus Aquastella is described to accommodate two new species of parasites of rotifers observed in Brooktrout Lake, New York State, USA. Three rotifer species – Keratella taurocephala,Polyarthra vulgaris, and Ploesoma truncatum – were infected, and this is the first report of oomycete infection in these species. Aquastella attenuata was specific to K. taurocephala and Aquastella aciculariswas specific to P. vulgaris and P. truncatum. The occurrence of infections correlated with peak host population densities and rotifers were infected in the upper layers of the water column. Sequencing of 18S rRNA and phylogenetic analysis of …

Coral Honeysuckle Easy To Propagate With Cuttings, W. John Hayden

Biology Faculty Publications

One of my earliest botanical/horticultural memories involves time spent with my dad taking cuttings of ornamental plants. Every spring, he would start several dozen new chrysanthemums from carefully overwintered stock plants. He was also fond of long yew hedges that he developed by taking numerous cuttings from just a few original shrubs in our yard. And, from time to time, both my grandmothers would propagate, via cuttings, house plants like geraniums, African violets, and Christmas cacti. But I think it was my dad’s comparatively larger scale operation that fascinated me; with just a little effort, a single shrub could yield …

A New Species Of Chiasmocleis (Microhylidae, Gastrophryninae) From The Atlantic Forest Of Espírito Santo State, Brazil, João Filipe Tonini, Maruicio Forlani, Rafael O. De Sá

Biology Faculty Publications

Among Neotropical microhylids, the genus Chiasmocleis is exceptionally diverse. Most species ofChiasmocleis were described in recent years based on external morphology, but recent studies using molecular data did not support the monophyly of the species groups clustered based on feet webbing. Furthermore, a phylogeographic study of C. lacrimae estimated high genetic divergence and low gene flow among populations across small geographic ranges. Increasing the molecular and geographic sampling, and incorporating morphological data, we identified new cryptic species. Herein, we used novel genetic and morphological data to describe a new species of Chiasmocleis.

Diet Alters Delayed Selfing, Inbreeding Depression, And Reproductive Senescence In A Freshwater Snail, Josh R. Auld, John F. Henkel

Biology Faculty Publications

No abstract provided.

Testing Predictions Of The Janzen–Connell Hypothesis: A Meta-Analysis Of Experimental Evidence For Distance- And Density- Dependent Seed And Seedling Survival, Liza S. Comita, Simon A. Queenborough, Stephen J. Murphy, Janelle L. Eck, Kaiyang Xu, Meghna Krishnadas, Noelle G. Beckman, Yan Zhu

Biology Faculty Publications

1. The Janzen–Connell hypothesis proposes that specialist natural enemies, such as herbivores and pathogens, maintain diversity in plant communities by reducing survival rates of conspecific seeds and seedlings located close to reproductive adults or in areas of high conspecific density. Variation in the strength of distance- and density-dependent effects is hypothesized to explain variation in plant species richness along climatic gradients, with effects predicted to be stronger in the tropics than the temperate zone and in wetter habitats compared to drier habitats.
2. We conducted a comprehensive literature search to identify peer-reviewed experimental studies published in the 40+ years since the hypothesis …

The Neotropical Genus Austrolebias: An Emerging Model Of Annual Killifishes, Nibia Berois, María J. Arezo, Rafael O. De Sá

Biology Faculty Publications

Annual fishes are found in both Africa and South America occupying ephemeral ponds that dried seasonally. Neotropical annual fishes are members of the family Rivulidae that consist of both annual and non-annual fishes. Annual species are characterized by a prolonged embryonic development and a relatively short adult life.

Males and females show striking sexual dimorphisms, complex courtship, and mating behaviors. The prolonged embryonic stage has several traits including embryos that are resistant to desiccation and undergo up to three reversible developmental arrests until hatching. These unique developmental adaptations are closely related to the annual fish life cycle and are the …

Probability Of Regenerating A Normal Limb After Bite Injury In The Mexican Axolotl (Ambystoma Mexicanum), Sierra Thompson, Laura Muzinic, Christopher Muzinic, Matthew L. Niemiller, S. Randal Voss

Biology Faculty Publications

Multiple factors are thought to cause limb abnormalities in amphibian populations by altering processes of limb development and regeneration. We examined adult and juvenile axolotls (Ambystoma mexicanum) in the Ambystoma Genetic Stock Center (AGSC) for limb and digit abnormalities to investigate the probability of normal regeneration after bite injury. We observed that 80% of larval salamanders show evidence of bite injury at the time of transition from group housing to solitary housing. Among 717 adult axolotls that were surveyed, which included solitary-housed males and group-housed females, approximately half presented abnormalities, including examples of extra or missing digits and …

Estimating Bacterial Diversity In Scirtothrips Dorsalis (Thysanoptera: Thripidae) Via Next Generation Sequencing, Aaron M. Dickey, Andrew J. Trease, Antonella Jara-Cavieres, Vivek Kumar, Matthew K. Christenson, Lakshmi-Prasad Potluri, J. Kent Morgan, Robert G. Shatters Jr., Cindy L. Mckenzie, Paul H. Davis, Lance S. Osborne

Biology Faculty Publications

The last 2 decades have produced a better understanding of insect-microbial associations and yielded some important opportunities for insect control. However, most of our knowledge comes from model systems. Thrips (Thysanoptera: Thripidae) have been understudied despite their global importance as invasive species, plant pests and disease vectors. Using a culture and primer independent next-generation sequencing and metagenomics pipeline, we surveyed the bacteria of the globally important pest, Scirtothrips dorsalis Hood. The most abundant bacterial phyla identified were Actinobacteria and Proteobacteria and the most abundant genera were Propionibacterium, Stenotrophomonas, and Pseudomonas. A total of 189 genera of bacteria were identified. The …

A Heterogenous Thermal Environment Enables Remarkable Behavioral Thermoregulation In Uta Stansburiana, Maria Goller, Franz Goller, Susannah S. French

Biology Faculty Publications

Ectotherms can attain preferred body temperatures by selecting specific temperature microhabitats within a varied thermal environment. The side-blotched lizard, Uta stansburiana may employ microhabitat selection to thermoregulate behaviorally. It is unknown to what degree habitat structural complexity provides thermal microhabitats for thermoregulation. Thermal microhabitat structure, lizard temperature, and substrate preference were simultaneously evaluated using thermal imaging. A broad range of microhabitat temperatures was available (mean range of 11°C within 1–2 m2) while mean lizard temperature was between 36°C and 38°C. Lizards selected sites that differed significantly from the mean environmental temperature, indicating behavioral thermoregulation, and maintained a temperature significantly above …

Novel Telomere-Anchored Pcr Approach For Studying Sexual Stage Telomeres In Aspergillus Nidulans, Nengding Wang, Saajidha Rizvydeen, Mithaq Vahedi, Daysi M. Vargas Gonzalez, Amanda L. Allred, Dustin Wayne Perry, Peter M. Mirabito, Karen E. Kirk

Biology Faculty Publications

Telomere length varies between germline and somatic cells of the same organism, leading to the hypothesis that telomeres are lengthened during meiosis. However, little is known about the meiotic telomere length in many organisms. In the filamentous fungus Aspergillus nidulans, the telomere lengths in hyphae and asexual spores are invariant. No study using existing techniques has determined the telomere length of the sexual ascospores due to the relatively low abundance of pure meiotic cells in A. nidulans and the small quantity of DNA present. To address this, we developed a simple and sensitive PCR strategy to measure the telomere length …

Chronic Lymphocytic Leukemia Cells In A Lymph Node Microenvironment Depict Molecular Signature Associated With An Aggressive Disease, Amit K. Mittal, Nagendra K. Chaturvedi, Karan J. Rai, Christine E. Gilling-Cutucache, Tara M. Nordgren, Margaret Moragues, Runqing Lu, Rene Opavsky, Greg R. Bociek, Dennis D. Weisenburger, Javeed Iqbal, Shantaram S. Joshi

Biology Faculty Publications

Chronic lymphocytic leukemia (CLL) cells survive longer in vivo than in vitro, suggesting that the tissue microenvironment provides prosurvival signals to tumor cells. Primary and secondary lymphoid tissues are involved in the pathogenesis of CLL, and the role of these tissue microenvironments has not been explored completely. To elucidate host-tumor interactions, we performed gene expression profiling (GEP) of purified CLL cells from peripheral blood (PB; n = 20), bone marrow (BM; n = 18), and lymph node (LN; n = 15) and validated key pathway genes by real-time polymerase chain reaction, immunohistochemistry and/or TCL1 trans-genic mice. Gene signatures representing several …

Sex Ratio Bias And Extinction Risk In An Isolated Population Of Tuatara (Sphenodon Punctatus), Kristine L. Grayson, Nicola J. Mitchell, Joanne M. Monks, Susan N. Keall, Joanna N. Wilson, Nicola J. Nelson

Biology Faculty Publications

Understanding the mechanisms underlying population declines is critical for preventing the extinction of endangered populations. Positive feedbacks can hasten the process of collapse and create an ‘extinction vortex,’ particularly in small, isolated populations. We provide a case study of a male-biased sex ratio creating the conditions for extinction in a natural population of tuatara (Sphenodon punctatus) on North Brother Island in the Cook Strait of New Zealand. We combine data from long term mark-recapture surveys, updated model estimates of hatchling sex ratio, and population viability modeling to measure the impacts of sex ratio skew. Results from the mark-recapture …

Effects Of Replacing Fishmeal With Squash Seed Meal (Cucurbita Maxima) On Performance Of Juvenile Nile Tilapia (Oreochromis Niloticus), Janice A. Ragaza, Jonni Fay C. Teves, Marie Noelle Fernandez

Biology Faculty Publications

The effects of replacing fishmeal with squash (Cucurbita maxima) seed meal (SSM) on Oreochromis niloticus juveniles were investigated on a 30-day feeding trial. Triplicate groups of ten (10) O. niloticus juveniles (2.54±0.949 g) stocked in polyethylene tanks received iso-nitrogenous diets with SSM inclusion levels of 0%, 5%, 10%, 15% and 20%. Fish fed 5% SSM inclusion level showed the highest average weight gain (202.25±36.26%) and specific growth rate (3.76±0.42%) among the fish fed SSM-containing diets. However, there were no significant differences between the average weight gain and specific growth rate of fish in all diets. Fish fed S5, S15 and …

Characterization Of In Vitro Transcriptional Responses Of Dorsal Root Ganglia Cultured In The Presence And Absence Of Blastema Cells From Regenerating Salamander Limbs, Antony Athippozhy, Jeffrey Lehrberg, James R. Monaghan, David M. Gardiner, S. Randal Voss

Biology Faculty Publications

During salamander limb regeneration, nerves provide signals that induce the formation of a mass of proliferative cells called the blastema. To better understand these signals, we developed a blastema-dorsal root ganglia (DRG) co-culture model system to test the hypothesis that nerves differentially express genes in response to cues provided by the blastema. DRG with proximal and distal nerve trunks were isolated from axolotls (Ambystoma mexicanum), cultured for five days, and subjected to microarray analysis. Relative to freshly isolated DRG, 1,541 Affymetrix probe sets were identified as differentially expressed and many of the predicted genes are known to function …

Evolutionary Change In Continuous Reaction Norms, Courtney J. Murren, Heidi J. Maclean, Sarah E. Diamond, Ulrich K. Steiner, Mary A. Heskel, Corey A. Handelsman, Cameron K. Ghalambor, Josh R. Auld, Hilary S. Callahan, David W. Pfennig, Rick A. Relyea, Carl D. Schlichting, Joel Kingsolver

Biology Faculty Publications

No abstract provided.

Humming Birds: Pollination Facts And Fancy, W. John Hayden

Biology Faculty Publications

Coral honeysuckle (Lonicera sempervirens), the 2014 VNPS Wildflower of the Year, is a classic example of a hummingbird-pollinated flower: bright red petals, often with contrasting yellow tones in the corolla throat, provide visual attraction, drawing hummingbirds to the flowers, where they are rewarded with a rich supply of nectar. Whereas hummingbirds have good color vision, they have a poor sense of smell. So it is not surprising that coral honeysuckle flowers are nearly scentless, at least to the human nose; even modern analytical instruments detect only traces of volatile molecules emanating from them. And open coral honeysuckle flowers, …

Evolutionary Relationships Of The Critically Endangered Frog Ericabatrachus Baleensis Largen, 1991 With Notes On Incorporating Previously Unsampled Taxa Into Large-Scale Phylogenetic Analyses, Karen Siu-Ting, David J. Gower, Davide Pisani, Roman Kassahun, Fikirte Gebresenbet, Michele Menegon, Abebe A. Mengistu, Samy A. Saber, Rafael O. De Sá, Mark Wilkinson, Simon P. Loader

Biology Faculty Publications

Background: The phylogenetic relationships of many taxa remain poorly known because of a lack of appropriate data and/or analyses. Despite substantial recent advances, amphibian phylogeny remains poorly resolved in many instances. The phylogenetic relationships of the Ethiopian endemic monotypic genus Ericabatrachus has been addressed thus far only with phenotypic data and remains contentious.

Results: We obtained fresh samples of the now rare and Critically Endangered Ericabatrachus baleensis and generated DNA sequences for two mitochondrial and four nuclear genes. Analyses of these new data using de novo and constrained-tree phylogenetic reconstructions strongly support a close relationship between Ericabatrachus and …

Analysis Of The Skin Transcriptome In Two Oujiang Color Varieties Of Common Carp, Chenghui Wang, Michael Wachholtz, Jun Wang, Xiaolin Liao, Guoqing Lu

Biology Faculty Publications

Background: Body color and coloration patterns are important phenotypic traits to maintain survival and reproduction activities. The Oujiang color varieties of common carp (Cyprinus carpio var. color), with a narrow distribution in Zhejiang Province of China and a history of aquaculture for over 1,200 years, consistently exhibit a variety of body color patterns. The molecular mechanism underlying diverse color patterns in these variants is unknown. To the practical end, it is essential to develop molecular markers that can distinguish different phenotypes and assist selective breeding.

Methodology/Principal Findings: In this exploratory study, we conducted Roche 454 transcriptome sequencing of …

Cluster M Mycobacteriophages Bongo, Pegleg, And Rey With Unusually Large Repertoires Of Trna Isotopes, Welkin H. Pope, Kirk R. Anders, Madison Baird, Charles A. Bowman, Michelle M. Boyle, Gregory W. Broussard, Tiffany Chow, Kari L. Clase, Shannon Cooper, Kathleen A. Cornely, Randall J. Dejong, Veronique A. Delesalle, Lisa Deng, David Dunbar, Nicholas P. Edgington, Christina M. Ferreira, Kathleen Weston Hafer, Grant A. Hartzog, J. Robert Hatherill, Lee E. Hughes, Khristina Ipapo, Gregory P. Krukonis, Christopher G. Meier, Denise L. Monti, Matthew R. Olm, Shallee T. Page, Craig L. Peebles, Claire A. Rinehart, Michael R. Rubin, Daniel A. Russell, Erin R. Sanders, Morgan Schoer, Christopher D. Shaffer, James Wherley, Edwin Vazquez, Han Yuan, Daiyuan Zhang, Steven G. Cresawn, Deborah Jacobs-Sera, Roger W. Hendrix, Graham F. Hatfull

Biology Faculty Publications

Genomic analysis of a large set of phages infecting the common hostMycobacterium smegmatis mc²155 shows that they span considerable genetic diversity. There are more than 20 distinct types that lack nucleotide similarity with each other, and there is considerable diversity within most of the groups. Three newly isolated temperate mycobacteriophages, Bongo, PegLeg, and Rey, constitute a new group (cluster M), with the closely related phages Bongo and PegLeg forming subcluster M1 and the more distantly related Rey forming subcluster M2. The cluster M mycobacteriophages have siphoviral morphologies with unusually long tails, are homoimmune, and have larger than average …

What Kind Of Seed Dormancy Might Palms Have?, Jerry M. Baskin, Carol C. Baskin

Biology Faculty Publications

Palm diaspores are reported to have various kinds of dormancy. However, (1) the embryo is underdeveloped; (2) the endocarp is water permeable; and (3) the diaspores take a long time to germinate. Thus, we conclude that the diaspores of the majority of palm species have morphophysiological dormancy (MPD). The ones that do not have MPD are morphologically dormant.