Life Sciences Commons^™

Predicting Leptodactylus (Amphibia, Anura, Leptodactylidae) Distributions: Broad-Ranging Versus Patchily Distributed Species Using A Presence-Only Environmental Niche Modeling Technique, Miguel Fernández, Daniel Cole, W. R. Heyer, Stephen Reichle, Rafael O. De Sá

Biology Faculty Publications

Locality data available for many, if not most, species of Neotropical frogs are based on written descriptions of the collecting sites, not on GPS device determined coordinate data. The pre-GPS device data are imprecise relative to GPS data. Niche modeling is a powerful technique for predicting geographic distributions that provides the best results when the locality data are precise. The purpose of this study is to determine whether imprecise historical locality data are sufficient such that niche modeling techniques can yield realistic new insights to species-level distributions. Two sets of frogs of the genus Leptodactylus that have known different kinds …

A Cembranoid From Tobacco Prevents The Expression Of Nicotineinduced Withdrawal Behavior In Planarian Worms, Oné R. Pagán, Amanda L. Rowlands, Angela L. Fattore, Tamara Coudron, Kimberly R. Urban, Apurva H. Bidja, Vesna A. Eterović

Biology Faculty Publications

Using an adaptation of published behavioral protocols, we determined that acute exposure to the cholinergic compounds nicotine and carbamylcholine decreased planarian motility in a concentration-dependent manner. A tobacco cembranoid (1S,2E,4R,6R,7E,11E)-cembra-2,7,11- triene-4,6-diol (4R-cembranoid), also decreased planarian motility. Experiments in the presence of 1 μM 4R-cembranoid did increase the IC50 for nicotine- but not carbamylcholine-induced decrease in planarian motility. When planarians were exposed for 24 h to either nicotine or carbamylcholine at concentrations near their respective IC50 values and then transferred to plain media, nicotineexposed, but not carbamylcholine- or cembranoid-exposed worms displayed withdrawal-like distress behaviors. In experiments where planarians were pre-exposed to …

The Mineralization Front Of The Eastern Oyster Is Cellular, Andrew S. Mount, Neeraj V. Gohad, Mary Beth Johnstone, Karolyn Hansen, Douglas C. Hansen

Biology Faculty Publications

Abstract of Technical Paper Presented at the 101^st Annual Meeting National Shellfisheries Association Savannah, Georgia March 22–26, 2009

Rapid Evolution Of Sex-Pheromone-Producing Enzyme In Drosophila, Troy R. Shirangi, Héloïse D. Dufour, Thomas M. Williams, Sean B. Carroll

Biology Faculty Publications

A wide range of organisms use sex pheromones to communicate with each other and to identify appropriate mating partners. While the evolution of chemical communication has been suggested to cause sexual isolation and speciation, the mechanisms that govern evolutionary transitions in sex pheromone production are poorly understood. Here, we decipher the molecular mechanisms underlying the rapid evolution in the expression of a gene involved in sex pheromone production in Drosophilid flies. Long-chain cuticular hydrocarbons (e.g., dienes) are produced female-specifically, notably via the activity of the desaturase DESAT-F, and are potent pheromones for male courtship behavior in Drosophila melanogaster. We …

Towards Biomimetic Ceramic Coatings: Cellular Aspects Of Oyster Shell Biomineralization, Mary Beth Johnstone, Karolyn Hansen, Neeraj V. Gohad, Douglas C. Hansen, Andrew S. Mount

Biology Faculty Publications

Abstract of Technical Paper Presented at the 101^st Annual Meeting National Shellfisheries Association Savannah, Georgia March 22–26, 2009

Assessment Of Oyster Shell Structural Properties For The Development Of 'Green' Composite Materials, Yuhchae Yoon, Andrew S. Mount, Douglas C. Hansen, Karolyn Hansen

Biology Faculty Publications

Abstract of Technical Paper Presented at the 101^st Annual Meeting National Shellfisheries Association Savannah, Georgia March 22–26, 2009

Rapid Fixation Of Non-Native Alleles Revealed By Genome-Wide Snp Analysis Of Hybrid Tiger Salamanders, Benjamin M. Fitzpatrick, Jarrett R. Johnson, D. Kevin Kump, H. Bradley Shaffer, Jeramiah J. Smith, S. Randal Voss

Biology Faculty Publications

BACKGROUND: Hybrid zones represent valuable opportunities to observe evolution in systems that are unusually dynamic and where the potential for the origin of novelty and rapid adaptation co-occur with the potential for dysfunction. Recently initiated hybrid zones are particularly exciting evolutionary experiments because ongoing natural selection on novel genetic combinations can be studied in ecological time. Moreover, when hybrid zones involve native and introduced species, complex genetic patterns present important challenges for conservation policy. To assess variation of admixture dynamics, we scored a large panel of markers in five wild hybrid populations formed when Barred Tiger Salamanders were introduced into …

Selective Herbivory By The Desert Woodrat (Neotoma Lepida) On Joshua Trees (Yucca Brevifolia), Monte P. Sanford, Nancy Huntly

Biology Faculty Publications

We studied herbivory by the desert woodrat (Neotoma lepida) on Joshua trees (Yucca brevifolia) in the Mojave Desert to determine whether N. lepida fed selectively based on leaf nitrogen content. We measured leaf nitrogen content and the location and amount of herbivory by woodrats on Y. brevifolia trees in southwestern Utah, USA. Neotoma lepida removed the outer tips of leaves (1/3 to 2/3 of total leaf length) but left leaf bases, which had lower nitrogen content, uneaten. Herbivory by N. lepida also was concentrated on rosettes that were oriented south, and these had significantly higher nitrogen …

A New Brevicipitid Species (Brevicipitidae: Callulina) From The Fragmented Forests Of The Taita Hills, Kenya, Simon P. Loader, G. John Measey, Rafael O. De Sá, Patrick K. Malonza

Biology Faculty Publications

A new species Callulina dawida is described from the Taita Hills, Kenya. It is distinguished from other members of the genus on the basis of the degree of digital expansion. The species further differs from other members of the genus based on molecular sequence comparisons and on its call. The morphological variation in the new species is described, including a comparison of internal and external characters and sexual dimorphism with other species of Callulina. The conservation status of the species, on the basis of its restricted distribution and land use changes in the area, is considered to be of …

Alternative Life Cycle Strategies And Colonization Of Young Anurans By Gorgoderina Attenuata In Nebraska, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr.

Biology Faculty Publications

Studies on life cycles and epizootiology of North American frog bladder flukes indicate that adult frogs become infected predominantly by ingesting tadpoles or other frogs that serve as second intermediate hosts for gorgoderid metacercariae. Other studies have indicated that newly metamorphosed frogs are rarely infected with these parasites because they are gape-limited predators that cannot feed on large intermediate hosts such as tadpoles and other frogs. We examined the role of potential intermediate hosts in the recruitment of the frog bladder fluke, Gorgoderina attenuata, to metamorphosed northern leopard frogs, Woodhouse’s toads, and bullfrogs from western Nebraska. We completed the …

Redescription Of The Frog Bladder Fluke Gorgoderina Attenuata From The Northern Leopard Frog, Rana Pipiens, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr.

Biology Faculty Publications

Morphological characters used to differentiate North American bladder flukes, Gorgoderina spp., are problematic and different authors use different morphological characteristics for distinguishing species. More importantly, no type specimens exist for four of the 12 North American species infecting anuran and caudatan hosts. A redescription of Gorgoderina attenuata (Stafford, 1902) Stafford, 1905 is based on new collections from 6 species of anurans from Arkansas, Nebraska, New York, and Wisconsin. Morphological comparisons between gravid G. attenuata recovered from bullfrogs and northern leopard frogs indicated statistically significant differences in 11 of 28 morphological characters examined. However, there was overlap among all of these …

Apicomplexan Parasites Co-Opt Host Calpains To Facilitate Their Escape From Infected Cells, Rajesh Chandramohanadas, Paul H. Davis, Daniel P. Beiting, Michael B. Harbut, Claire Darling, Geetha Velmourougane, Ming Yeh Lee, Peter A. Greer, David S. Roos, Doron C. Greenbaum

Biology Faculty Publications

Apicomplexan parasites, including Plasmodium falciparum and Toxoplasma gondii (the causative agents of malaria and toxoplasmosis, respectively), are responsible for considerable morbidity and mortality worldwide. These pathogenic protozoa replicate within an intracellular vacuole inside of infected host cells, from which they must escape to initiate a new lytic cycle. By integrating cell biological, pharmacological, and genetic approaches, we provide evidence that both Plasmodium and Toxoplasma hijack host cell calpain proteases to facilitate parasite egress. Immunodepletion or inhibition of calpain-1 in hypotonically lysed and resealed erythrocytes prevented the escape of P. falciparum parasites, which was restored by adding purified calpain-1. Similarly, efficient …

Do Hypothermic Tissue Tolerances Limit Torpor Expression?, Clark J. Cotton, Henry J. Harlow

Biology Faculty Publications

1. Arrest temperatures and Q₁₀ values for extensor digitorum longus (EDL), soleus, trabecula, and jejunum muscle twitch strength, contraction time, and 0.5 relaxation time were calculated for a deep torpor hibernator, white-tailed prairie dog (WTPD) (Cynomys leucurus), a shallow torpor hibernator, black-tailed prairie dog (BTPD) (Cynomys ludovicianus), and a non-hibernator, lab rat (Rattus norvegicus) to test the hypothesis that tissue temperature tolerances limit the depth of expressed torpor.

2. There were no temperature tolerance differences between the tissues of the two species of hibernators. Both hibernating species had arrest temperatures and Q_{10 …}

Common-Path Multimodal Optical Microscopy, Marla Tipping, Chandra S. Yelleswarapu, Sri-Rajasekhar Kothapalli, Alexey Veraksa, D.V.G.L.N. Rao

Biology Faculty Publications

We have developed a common-path multimodal optical microscopy system that is capable of using a single optical source and a single camera to image amplitude, phase, and fluorescence features of a biological specimen. This is achieved by varying either contrast enhancement filters at the Fourier plane and/or neutral density/fluorescence filters in front of the CCD camera. The feasibility of the technique is demonstrated by obtaining brightfield, fluorescence, phase-contrast, spatially filtered, brightfield + fluorescence, phase +fluorescence, and edge-enhanced+fluorescence images of the same Drosophila embryo without the need for image registration and fusion. This comprehensive microscope has the capability of providing both …

Integrating Lethal And Nonlethal Approaches For Management Of Suburban Deer, Jason R. Boulanger, Paul D. Curtis, Michael Ashdown

Biology Faculty Publications

Evaluations of white-tailed deer (Odocoileus virginianus) population management in suburban landscapes has included debate over lethal control (e.g., sharp-shooting and hunting). These management techniques are often stymied by political impediments, safety concerns, and public attitudes. We are implementing the novel use of surgical sterilization in combination with hunting to mitigate deer-related impacts on Cornell University lands near Ithaca, New York. The project lands are composed of 2 zones: a suburban core campus area (446 ha) and adjacent outlying areas that contain agricultural fields and natural areas where deer hunting is permitted (582 ha). Surgical sterilization will be the …

Hunker Down And Hold On: Contractile Roots Give Skunk Cabbage Another Special Trait, W. John Hayden

Biology Faculty Publications

I can remember the first time I ever heard of contractile roots. It was in graduate school at the University of Maryland and a friend of mine was busy preparing a lecture on roots. He said to me something like “Did you ever notice, while pulling up dandelions, that the darn weed seems to be pulling back? As it turns out, it is!” Strange but true, dandelions, along with a diverse assemblage of other species, have contractile roots that serve to pull the plant downward. In this capacity, contractile roots go well beyond the routine function of providing anchorage for …

Proteomic Comparison Of Entamoeba Histolytica And Entamoeba Dispar And The Role Of E. Histolytica Alcohol Dehydrogenase 3 In Virulence, Paul H. Davis, Minghe Chen, Xiaochun Zhang, C. Graham Clark, R. Reid Townsend, Samuel L. Stanley

Biology Faculty Publications

The protozoan intestinal parasite Entamoeba histolytica infects millions of people worldwide and is capable of causing amebic dysentery and amebic liver abscess. The closely related species Entamoeba dispar colonizes many more individuals, but this organism does not induce disease. To identify molecular differences between these two organisms that may account for their differential ability to cause disease in humans, we used two-dimensional gel-based (DIGE) proteomic analysis to compare whole cell lysates of E. histolytica and E. dispar. We observed 141 spots expressed at a substantially (.5- fold) higher level in E. histolytica HM-1:IMSS than E. dispar and 189 spots showing …

Altered Regulation Of Aquaporin Gene Expression In Allergen And Il-13-Induced Mouse Models Of Asthma, Carissa M. Krane, Bijia Deng, Venkateshwar Mutyam, Casey A. Mcdonald, Stephen Pazdziorko, Lawrence Mason, Samuel Goldman, Marion Kasaian, Divya Chaudhary, Cara Williams, Melisa W.Y. Ho

Biology Faculty Publications

IL-13 is known to affect many processes that contribute to an asthmatic phenotype, including inflammation, fibrosis, and mucus production. Members of the aquaporin (AQP) family of transmembrane water channels are targets of regulation in models of lung injury and inflammation. Therefore, we examined AQP mRNA and protein expression in allergen and IL-13-induced mouse models of asthma. Lungs from ovalbumin sensitized and ovalbumin challenged (OVA/OVA) and IL-13 treated mice showed airway thickening, increased mucus production, and pulmonary eosinophilia. Pulmonary function tests showed a significant increase in methacholine-induced airway hyperreactivity in OVA/OVA and IL-13-treated mice as compared with controls. Quantitative PCR analysis …

Historical Information On Bird Distributions Indicates That Mute Swans Were Introduced To North America, Robert A. Askins

Biology Faculty Publications

No abstract provided.

Ambystoma Maculatum (Spotted Salamander) Occurrence, Kristine L. Grayson, A. M. Bloch

Biology Faculty Publications

Natural History Notes: Ambystoma maculatum is a wide ranging mole salamander found from Nova Scotia and southern Ontario through Georgia and eastern Texas (Conant and Collins 1998).

Granite Rock Outcrops: An Extreme Environment For Soil Nematodes?, Erin Austin, Katharine Semmens, Charles Parsons, Amy M. Treonis

Biology Faculty Publications

We studied soil nematode communities from the surface of granite flatrock outcrops in the eastern Piedmont region of the United States. The thin soils that develop here experience high light intensity and extreme fluctuations in temperature and moisture and host unique plant communities. We collected soils from outcrop microsites in Virginia (VA) and North Carolina (NC) in various stages of succession (Primitive, Minimal, and Mature) and compared soil properties and nematode communities to those of adjacent forest soils. Nematodes were present in most outcrop soils, with densities comparable to forest soils (P > 0.05). Nematode communities in Mature and Minimal soils …

Species Delimitation In Lemurs: Multiple Genetic Loci Reveal Low Levels Of Species Diversity In The Genus Cheirogaleus, Linn F. Groeneveld, David W. Weisrock, Rodin M. Rasoloarison, Anne D. Yoder, Peter M. Kappeler

Biology Faculty Publications

BACKGROUND: Species are viewed as the fundamental unit in most subdisciplines of biology. To conservationists this unit represents the currency for global biodiversity assessments. Even though Madagascar belongs to one of the top eight biodiversity hotspots of the world, the taxonomy of its charismatic lemuriform primates is not stable. Within the last 25 years, the number of described lemur species has more than doubled, with many newly described species identified among the nocturnal and small-bodied cheirogaleids. Here, we characterize the diversity of the dwarf lemurs (genus Cheirogaleus) and assess the status of the seven described species, based on phylogenetic and …

Sex- And Context-Dependent Migration In A Pond-Breeding Amphibian, Kristine L. Grayson, Henry M. Wilbur

Biology Faculty Publications

Partial migration, variation in the percentage of a population that completes a migration, can be influenced by the local environment and condition of an individual. We examined the direct and interacting effects of habitat quality and gender on migration decision by manipulating population density and sex ratio in a factorial field experiment using aquatic enclosures. In partially migrating red-spotted newts (Notophthalmus viridescens), we measured the percentage of newts migrating to the terrestrial habitat vs. overwintering as pond residents. Density significantly influenced migration, with 63% of newts migrating from high-density enclosures compared to 39% from low-density enclosures. Newts also …

Protein Nutrition Of Southern Plains Small Mammals: Immune Response To Variation In Maternal And Offspring Dietary Nitrogen, James A. Wilson, Jennifer L. Parsons, Eric E. Jorgensen

Biology Faculty Publications

Maternal nutrition during pregnancy and postnatal offspring nutrition may influence offspring traits. We investigated the effects of maternal and post weaning offspring dietary nitrogen on immune function and hematology in two species of rodent: the hispid cotton rat (Sigmodon hispidus), a primarily herbivorous rodent, and the fulvous harvest mouse (Reithrodontomys fulvescens), an omnivore. These two species responded differently to the same levels of treatment, with cotton rats primarily influenced by maternal diet and harvest mice by post weaning offspring diet. Cotton rats born to mothers on high-nitrogen diets had lower values of mean corpuscle volume and hemoglobin and greater concentrations …

Microarray And Cdna Sequence Analysis Of Transcription During Nerve-Dependent Limb Regeneration, James R. Monaghan, Leonard G. Epp, Srikrishna Putta, Robert B. Page, John A. Walker, Chris K. Beachy, Wei Zhu, Gerald M. Pao, Inder M. Verma, Tony Hunter, Susan V. Bryant, David M. Gardiner, Tim T. Harkins, S. Randal Voss

Biology Faculty Publications

Background

Microarray analysis and 454 cDNA sequencing were used to investigate a centuries-old problem in regenerative biology: the basis of nerve-dependent limb regeneration in salamanders. Innervated (NR) and denervated (DL) forelimbs of Mexican axolotls were amputated and transcripts were sampled after 0, 5, and 14 days of regeneration.

Results

Considerable similarity was observed between NR and DL transcriptional programs at 5 and 14 days post amputation (dpa). Genes with extracellular functions that are critical to wound healing were upregulated while muscle-specific genes were downregulated. Thus, many processes that are regulated during early limb regeneration do not depend upon nerve-derived factors. …

Genic Regions Of A Large Salamander Genome Contain Long Introns And Novel Genes, Jeramiah J. Smith, Srikrishna Putta, Wei Zhu, Gerald M. Pao, Inder M. Verma, Tony Hunter, Susan V. Bryant, David M. Gardiner, Timothy T. Harkins, S. Randal Voss

Biology Faculty Publications

BACKGROUND: The basis of genome size variation remains an outstanding question because DNA sequence data are lacking for organisms with large genomes. Sixteen BAC clones from the Mexican axolotl (Ambystoma mexicanum: c-value = 32 x 10(9) bp) were isolated and sequenced to characterize the structure of genic regions.

RESULTS: Annotation of genes within BACs showed that axolotl introns are on average 10x longer than orthologous vertebrate introns and they are predicted to contain more functional elements, including miRNAs and snoRNAs. Loci were discovered within BACs for two novel EST transcripts that are differentially expressed during spinal cord regeneration and skin …

Microarray And Cdna Sequence Analysis Of Transcription During Nerve-Dependent Limb Regeneration, James R. Monaghan, Leonard G. Epp, Srikrishna Putta, Robert B. Page, John A. Walker, Chris K. Beachy, Wei Zhu, Gerald M. Pao, Inder M. Verma, Tony Hunter, Susan V. Bryant, David M. Gardiner, Tim T. Harkins, S. Randal Voss

Biology Faculty Publications

BACKGROUND: Microarray analysis and 454 cDNA sequencing were used to investigate a centuries-old problem in regenerative biology: the basis of nerve-dependent limb regeneration in salamanders. Innervated (NR) and denervated (DL) forelimbs of Mexican axolotls were amputated and transcripts were sampled after 0, 5, and 14 days of regeneration.

RESULTS: Considerable similarity was observed between NR and DL transcriptional programs at 5 and 14 days post amputation (dpa). Genes with extracellular functions that are critical to wound healing were upregulated while muscle-specific genes were downregulated. Thus, many processes that are regulated during early limb regeneration do not depend upon nerve-derived factors. …

In Vitro Guidance Of Retinal Axons By A Tectal Lamina-Specific Glycoprotein Nel, Yulan Jiang, Hiroya Obama, Soh-Leh Kuan, Ritsuko Nakamura, Chizu Nakamoto, Zhufeng Ouyang, Masaru Nakamoto

Biology Faculty Publications

Nel is a glycoprotein containing five chordin-like and six epidermal growth factor-like domains and is strongly expressed in the nervous system. In this study, we have examined expression patterns and in vitro functions of Nel in the chicken retinotectal system. We have found that in the developing tectum, expression of Nel is localized in specific laminae that retinal axons normally do not enter, including the border between the retinorecipient and non-retinorecipient laminae. Nel-binding activity is detected on retinal axons both in vivo and in vitro, suggesting that retinal axons express a receptor for Nel. In vitro, Nel inhibits retinal axon …

Investigation Of A Fresh African Elephant Carcass By Conspecifics, Christen Merte, Katie Gough, Bruce A. Schulte

Biology Faculty Publications

This examination of elephant bones and ivory indicates that elephants show an elevated level of interest in conspecifics over other dead animals. Elephants do not seem to express special interest in dead kin but rather they appear to have a generalized response to injured, dying and deceased conspecifics (Douglas Hamilton et al. 2006, McComb et al. 2006). The present study reports the behaviour of a group of elephants in response to a euthanized adult male elephant that suffered severe wounds inflicted by a conspecific male. Most of the observations from previous studies have been on females and female group members. …

Cuscuta Jepsonii (Convolvulaceae): An Invasive Weed Or An Extinct Endemic?, Mihai Costea, Saša Stefanović

Biology Faculty Publications

Despite their ecological significance, parasitic plants face more conservation challenges than do autotrophic plants. This is especially true for the groups that include weedy or invasive species such as Cuscuta. While approximately half of the Cuscuta (dodders) species may require conservation measures, the genus as a whole is sometimes posted on governmental lists of noxious or quarantine weeds. Our study challenges this stereotype and uses the case of C. jepsonii (Jepson’s dodder) to illustrate the precarious biodiversity and conservation status faced by many dodder species. Until now, Jepson’s dodder has been known only from its type collection. Consequently, its …