Digital Commons Network^™

Phylogenetic Relationships Of African Microhylid Frogs Inferred From Dna Sequences Of Mitochondrial 12s And 16s Rrna Genes, Simon P. Loader, David J. Gower, Kim M. Howell, Nike Doggart, Mark-Oliver Rödel, Barry T. Clarke, Rafael O. De Sá, Bernard L. Cohen, Mark Wilkinson

Biology Faculty Publications

The phylogenetic relationships of microhylid frogs are poorly understood. The first molecular phylogeny for continental African microhylids is presented, including representatives of all subfamilies, six of the eight genera, and the enigmatic hemisotid Hemisus. Mitochondrial 12S and 16S rRNA sequence data were analysed using parsimony, likelihood and Bayesian methods. Analyses of the data are consistent with the monophyly of all sampled subfamilies and genera. Hemisus does not nest within either brevicipitines or non-brevicipitines. It is possibly the sister group to brevicipitines, in which case brevicipitines might not be microhylids. Phrynomantis and Hoplophryne potentially group with non-African, non-brevicipitine microhylids, in …

Monitoring Activity Of Drosophila Larvae: Impedance & Video Microscopy Measures, Ann Simone Cooper, Robin L. Cooper

Biology Faculty Publications

No abstract provided.

Monitoring Heart Rate In Drosophila Larvae By Various Approaches, Sameera Dasari, Robin L. Cooper

Biology Faculty Publications

No abstract provided.

Monitoring Carbon Dioxide Production By Drosophila Larvae, Robin L. Cooper, D. Nicholas Mcletchie

Biology Faculty Publications

No abstract provided.

Apparent Sibling Rivalry In The Freshwater Clam Sphaerium Striatinum, Mark Beekey, Ronald H. Karlson

Biology Faculty Publications

In Sphaerium striatinum, a freshwater brooding bivalve, up to 97.5% of offspring that adults initially produce fail to reach independence. Marsupial sacs, specialized extensions of gill filaments that act as nurseries, initially contain multiple offspring in various sizes and stages of development. However, by the time offspring reach later stages of development, marsupial sacs typically contain only one offspring. Brood mortality is hypothesized to be the result of competition among embryos for nutrients and/or space. Sphaeriid eggs do not contain enough yolk for offspring to complete development. Adults supply additional nutrients required to reach independence. Brood capacity is limited by …

Two Drosophila Suppressors Of Cytokine Signaling (Socs) Differentially Regulate Jak And Egfr Pathway Activities, Jason S. Rawlings, Gabriela Rennebeck, Susan M.W. Harrison, Rongwen Xi, Douglas A. Harrison

Biology Faculty Publications

BACKGROUND: The Janus kinase (JAK) cascade is an essential and well-conserved pathway required to transduce signals for a variety of ligands in both vertebrates and invertebrates. While activation of the pathway is essential to many processes, mutations from mammals and Drosophila demonstrate that regulation is also critical. The SOCS (Suppressor Of Cytokine Signaling) proteins in mammals are regulators of the JAK pathway that participate in a negative feedback loop, as they are transcriptionally activated by JAK signaling. Examination of one Drosophila SOCS homologue, Socs36E, demonstrated that its expression is responsive to JAK pathway activity and it is capable of downregulating …

Growth Of Stygobitic (Orconectes Australis Packardi) And Epigean (Orconectes Cristavarius) Crayfishes Maintained In Laboratory Conditions, Ann-Simone Cooper, Robin L. Cooper

Biology Faculty Publications

This study reports on maintenance and growth of the cave crayfish, Orconectes australis packardi, and the epigean crayfish, Orconectes cristavarius, with laboratory conditions for 1 and 2 years. The O. a. packardi survived well compared to the O. cristavarius in captivity. The poor survival of the epigean species was probably due to unsuitable conditions. The epigean as well as the cave crayfish molted and grew in captivity, but without any significant difference in molt frequency between species. In the first year, total body length was obtained to assay growth, whereas in the second year the more accurate measure …

The Bvg Virulence Control System Regulates Biofilm Formation In Bordetella Bronchiseptica, Yasuhiko Irie, Seema Mattoo, Ming H. Yuk

Biology Faculty Publications

Bordetella species utilize the BvgAS (Bordetella virulence gene) two-component signal transduction system to sense the environment and regulate gene expression among at least three phases: a virulent Bvg⁺ phase, a nonvirulent Bvg⁻ phase, and an intermediate Bvgⁱ phase. Genes expressed in the Bvg⁺ phase encode known virulence factors, including adhesins such as filamentous hemagglutinin (FHA) and fimbriae, as well as toxins such as the bifunctional adenylate cyclase/hemolysin (ACY). Previous studies showed that in the Bvgⁱ phase, FHA and fimbriae continue to be expressed, but ACY expression is significantly downregulated. In this report, we determine …

Zebra Mussels Affect Benthic Predator Foraging Success, Mark Beekey, D. J. Mccabe, I. E. Marsden

Biology Faculty Publications

The introduction of zebra mussels (Dreissena spp.) to North America has resulted in dramatic changes to the complexity of benthic habitats. Changes in habitat complexity may have profound effects on predator-prey interactions in aquatic communities. Increased habitat complexity may affect prey and predator dynamics by reducing encounter rates and foraging success. Zebra mussels form thick contiguous colonies on both hard and soft substrates. While the colonization of substrata by zebra mussels has generally resulted in an increase in both the abundance and diversity of benthic invertebrate communities, it is not well known how these changes affect the foraging efficiencies of …

From Biomedicine To Natural History Research: Est Resources For Ambystomatid Aalamanders, Srikrishna Putta, Jeramiah J. Smith, John A. Walker, Mathieu Rondet, David W. Weisrock, James Monaghan, Amy K. Samuels, D. Kevin Kump, David C. King, Nicholas J. Maness, Bianca Habermann, Elly Tanaka, Susan V. Bryant, David M. Gardiner, David M. Parichy, S. Randal Voss

Biology Faculty Publications

BACKGROUND: Establishing genomic resources for closely related species will provide comparative insights that are crucial for understanding diversity and variability at multiple levels of biological organization. We developed ESTs for Mexican axolotl (Ambystoma mexicanum) and Eastern tiger salamander (A. tigrinum tigrinum), species with deep and diverse research histories.

RESULTS: Approximately 40,000 quality cDNA sequences were isolated for these species from various tissues, including regenerating limb and tail. These sequences and an existing set of 16,030 cDNA sequences for A. mexicanum were processed to yield 35,413 and 20,599 high quality ESTs for A. mexicanum and A. t. tigrinum, respectively. Because the …

Integrating Research And Teaching Labs With The Module Evolution Approach, Michael S. Reagan

Biology Faculty Publications

No abstract provided.

A New Toad (Anura: Bufonidae) From Uruguay, Raúl Maneyro, Diego Arrieta, Rafael O. De Sá

Biology Faculty Publications

A new species of toad is described from small streams in the hills of Cuchilla de Haedo and Cuchilla Grande in northeastern Uruguay. Specimens of the new species were previously mistaken for Bufo arenarum; they differ from B.arenarum by having elongated parotoid glands and reddish-brown parotoid and cephalic crests. A discriminant analysis resulted in three groups corresponding to B. arenarum, Bufo rufus, and the specimens herein described as a new species.

A New Species Of Callulina (Anura: Microhylidae) From The West Usambara Mountains, Tanzania, Rafael O. De Sá, Simon P. Loader, Alan Channing

Biology Faculty Publications

The description of the species Callulina kreffti was based on specimens collected in the East Usambara Mountains of Tanzania. Successive collecting has shown this species to be widely distributed through the Eastern Arc Mountains. Advertisement calls from populations in the type locality of Callulina kreffti were compared with calls from populations in the West Usambara Mountains. Analysis of the calls suggested that these two populations of Callulina represent two separate taxa. Subsequent morphological and molecular investigations indicated that these two populations are distinct. Herein, we describe a new Callulina species on the basis of call, morphology and molecular sequences.

Drosophila As An Emerging Model To Study Metastasis, Madhuri Kango-Singh, Georg Halder

Biology Faculty Publications

Metastasis is the primary cause of human cancer-related deaths. Two recent studies describe a system for testing how multiple genetic events synergize to promote neoplastic growth and metastasis in Drosophila, paving the way for systematic approaches to understanding metastasis using the powerful tools of Drosophila genetics.

Phylogenetic Signal And The Utility Of 12s And 16s Mtdna In Frog Phylogeny, S. Hertwig, Rafael O. De Sá, A. Haas

Biology Faculty Publications

Genes selected for a phylogenetic study need to contain conserved information that reflects the phylogenetic history at the specific taxonomic level of interest. Mitochondrial ribosomal genes have been used for a wide range of phylogenetic questions in general and in anuran systematics in particular. We checked the plausibility of phylogenetic reconstructions in anurans that were built from commonly used 12S and 16S rRNA gene sequences. For up to 27 species arranged in taxon sets of graded inclusiveness, we inferred phylogenetic hypotheses based on different apriori decisions, i.e. choice of alignment method and alignment parameters, including/excluding variable sites, choice of reconstruction …

Seed Mass And Morphology In Outcrossing And Selfing Species Of Clarkia (Onagraceae): An Sem Study, Jennifer L. Knies, Veronique A. Delesalle, A. R. Cavaliere

Biology Faculty Publications

Seeds from three pairs of outcrossing-selfing sister taxa from the genus Clarkia (farewell-to-spring, Onagraceae)—Clarkia unguiculata, Clarkia exilis, Clarkia xantiana ssp. xantiana and ssp. parviflora, and Clarkia concinna ssp. concinna and ssp. automixa—were studied to assess the effects of contrasting mating systems on seed mass and seed morphology. For each outcrossing-selfing comparison, the seed mass of the selfing taxon was less than that of the outcrossing taxon. Seed mass typically differed significantly among populations within a taxon. Scanning electron microscopy showed that the seeds from all these taxa share several characteristics: a bullet to shield shape, a reticulate exotesta pattern, presence …

Loss-Of-Function Analysis Of Epha Receptors In Retinotectal Mapping, David Feldheim, Masaru Nakamoto, Miriam Osterfield, Nicholas Gale, Thomas Dechiara, Rajat Rohatgi, George Yancopoulos, John Flanagan

Biology Faculty Publications

EphA tyrosine kinases are thought to act as topographically specific receptors in the well-characterized projection map from the retina to the tectum. Here, we describe a loss-of-function analysis of EphA receptors in retinotectal mapping. Expressing patches of a cytoplasmically truncated EphA3 receptor in chick retina caused temporal axons to have reduced responsiveness to posterior tectal repellent activity in vitro and to shift more posteriorly within the map in vivo . A gene disruption of mouse EphA5, replacing the intracellular domain with beta-galactosidase, reduced in vitro responsiveness of temporal axons to posterior target membranes. It also caused map abnormalities in vivo …

Morphological Characteristics And Species Separation Of Hawaiian Postlarval Amphidromous Fishes, M. Eric Benbow, Albert J. Burky, Carl M. Way

Biology Faculty Publications

There are five Hawaiian amphidromous fishes (Gobiidae: Lentipes concolor, Awaous guamensis, Sicyopterus stimpsoni, Stenogobius hawaiiensis; Eleotridae: Eleotris sandwicensis). Amphidromous adults deposit eggs on the stream bottom. After hatching, larvae drift to the ocean for growth followed by postlarval migration back into the streams. Postlarvae were collected to construct a dichotomous identification key based on 12 morphological measures and ray counts from four fins. Overall, the presense of fused pelvic fins, standard length (SL), and fin ray numbers were the most useful in species separation. Gobies were separated from the eleotrid by the former having fused …

Least Shrew (Cryptotis Parva ) In Extreme West-Central Nebraska, Keith Geluso, Jeremy A. White, Michael A. Bogen

Biology Faculty Publications

During the past 35 years, the least shrew (Cryptotis parva) has expanded its distribution along riverine and other mesic corridors in western parts of its distribution, although some recently discovered populations in the West might represent relicts of a previous Pleistocene distribution. In Nebraska, the least shrew originally was known only from eastern and central parts of the state, but recent records are now available from extreme west-central Nebraska and the northwestern corner of the state. Our record from west-central Nebraska probably represents recent westward expansion of C. parua along the North Platte River. This capture in Scotts …

Dynamics Of Rodent Assemblages Inhabiting Abandoned Petroleum Landfarms In Oklahoma, James Wilson, R. L. Lochmiller, D. M. Janz

Biology Faculty Publications

Studies on the effects of anthropogenic contamination on wildlife have largely been focused at the individual level. Biomarkers have been used to monitor changes in the health of individuals exposed to contaminants; however, little attention has been given to the effects of chronic exposure at the population or community levels. We studied rodent assemblages from uncontaminated (reference) sites (n 5 5) and abandoned petrochemical landfarms (n 5 5) in Oklahoma to investigate potential alterations in community structure and composition. Rodent assemblages inhabiting landfarms had lower species diversity, lower richness, and a more even distribution of individuals across species. Reference sites …

Organochlorine Pesticides In Chlorioallantoic Membranes Of Morelet's Crocodile Eggs From Belize, Christopher B. Pepper, Thomas R. Rainwater, Steven G. Platt, Jennifer A. Dever, Todd A. Anderson, Scott T. Mcmurry

Biology Faculty Publications

Recent studies examined the utility of the chorioallantoic membrane (CAM) as a nonlethal, noninvasive indicator of environmental contaminant exposure in oviparous wildlife. The CAM is a highly vascularized extraembryonic membrane that functions as a site for respiration, nutrient transport, and waste storage during embryonic development. After hatching, the CAM is usually discarded with the eggshell and can be used for chemical residue analysis. Chorioallantoic membranes have been used successfully to examine contaminant exposure and predict chemical concentrations in multiple species of birds and reptiles. In this study, we examined organochlorine (OC) pesticide concentrations in CAMs from eggs of Morelet's crocodiles …

Endocrine-Disrupting Effects Of Cattle Feedlot Effluent On An Aquatic Sentinel Species, The Fathead Minnow, Edward Orlando, Alan Kolok, Gerry Binzcick, Jennifer Gates, Megan Horton, Christy Lambright, L. Earl Gray Jr., Ana M. Soto, Louis J. Guilette

Biology Faculty Publications

Over the last decade, research has examined the endocrine-disrupting action of various environmental pollutants, including hormones, pharmaceuticals, and surfactants, in sewage treatment plant effluent. Responding to the growth of concentrated animal feeding operations (CAFOs) and the pollutants present in their wastewater (e.g., nutrients, pharmaceuticals, and hormones), the U.S. Environmental Protection Agency developed a new rule that tightens the regulation of CAFOs. In this study, we collected wild fathead minnows (Pimephales promelas) exposed to feedlot effluent (FLE) and observed significant alterations in their reproductive biology. Male fish were demasculinized (having lower testicular testosterone synthesis, altered head morphometrics, and smaller …

Diet Quality And Food Limitation Affect The Dynamics Of Body Composition And Digestive Organs In A Migratory Songbird (Zonotrichia Albicollis), Barbara J. Pierce, Scott R. Mcwilliams

Biology Faculty Publications

Migrating songbirds interrupt their feeding to fly between stopover sites that may vary appreciably in diet quality. We studied the effects of fasting and food restriction on body composition and digestive organs in a migratory songbird and how these effects interacted with diet quality to influence the rate of recovery of nutrient reserves. Food limitation caused whitethroated sparrows to reduce both lean and fat reserves, with about 20% of the decline in lean mass represented by a decline in stomach, small intestine, and liver. During refeeding on diets similar in nutrient composition to either grain or fruit, foodlimited grain-fed birds …

The Effect Of Size-Limited Brood Capacity On Brood Size In A Freshwater Bivalve, Mark Beekey

Biology Faculty Publications

Size limited brood capacity is common among species with hard exoskeletons or shells. In these species, brood size is limited by the physical capacity to hold offspring. Here we present evidence that brood size is limited by physical constraints in Sphaerium striatinum , a small brooding bivalve. Sphaerium striatinum is a sequential brooder and produces offspring throughout the year. Offspring are brooded in marsupial sacs located on the inner demibranch. In an unconstrained brooder one would predict that brood size would increase as a function of adult length cubed, a volumetric relationship. In S. striatinum, brood size increases as less …

Similarity Of Mammalian Body Size Acrossthe Taxonomic Hierarchy And Across Space And Time, F. A. Smith, J. H. Brown, J. P. Haskell, S. K. Lyons, J. Alroy, E. L. Charnov, T. Dayan, B. J. Enquist, S.K. Morgan Ernest, E. A. Hadly, K. E. Jones, D. M. Kaufman, P. A. Marquet, B. A. Maurer, K. J. Niklas, W. P. Porter, B. Tiffney, M. R. Willig

Biology Faculty Publications

Although it is commonly assumed that closely related animals are similar in body size, the degree of similarity has not been examined across the taxonomic hierarchy. Moreover, little is known about the variation or consistency of body size patterns across geographic space or evolutionary time. Here, we draw from a data set of terrestrial, nonvolant mammals to quantify and compare patterns across the body size spectrum, the taxonomic hierarchy, continental space, and evolutionary time. We employ a variety of statistical techniques including “sib-sib” regression, phylogenetic autocorrelation, and nested ANOVA. We find an extremely high resemblance (heritability) of size among congeneric …

Hydrologic Variability, Organic Matter Supply, Anddenitrification In The Garonne River Ecosystem, Michelle A. Baker, P. Vervier

Biology Faculty Publications

1. Groundwater nitrate contamination has become a worldwide problem as increasing amounts of nitrogen fertilisers are used in agriculture. Alluvial groundwater is uniquely juxtaposed between soils and streams. Hydrological connections among these subsystems regulate nutrient cycling.

2. We measured denitrification using an in situ acetylene‐block assay in a nitrate‐contaminated portion of the Garonne River catchment along a gradient of surface water–ground water mixing during high (snowmelt) and low flow.

3. During high flow (mid‐April to early June) the water table rose an average of 35 cm and river water penetrated the subsurface to a great extent in monitoring wells. Denitrification …

Reproduction And Seasonal Activity Of Silver-Haired Bats In Western Nebraska, Keith Geluso, Jeffrey J. Huebschman, Jeremy A. White, Michael A. Bogen

Biology Faculty Publications

Silver-haired bats (Lasionycteris noctivagans) were thought only to migrate through Nebraska; however, recent surveys in eastern Nebraska report summer records of females and their young. Our study in western Nebraska also shows that silver-haired bats are summer residents. We discovered the 1st reproductively active L. noctivagans in this part of the state. We caught lactating females and volant young in riparian forests along the North Platte River and in forested areas of the Pine Ridge. Previously, adult males were not known from Nebraska in summer, and only 4 records of L. noctivagans were known from western Nebraska during …

Grassland Diversity And Productivity: The Interplay Of Resource Availability And Propagule Pools, Bryan L. Foster, Timothy L. Dickson

Biology Faculty Publications

Processes operating at multiple spatial scales govern the structure and functioning of ecological communities. We conducted a resource manipulation and propagule addition experiment in grassland to evaluate the interaction of local resource availability and propagule pools in governing local-scale plant colonization, biodiversity, and above-ground productivity. The availabilities of establishment microsites and water were manipulated in field plots for two years through the application of experimental soil disturbances and irrigation, respectively. Resource manipulations led to increased invasibility of the community, as predicted by the theory of fluctuating resources. Rates of colonization,enhanced by the sowing of 32 grassland species, increased plant diversity …

Seasonal Activity And Reproduction In Bats Of East-Central Nebraska, Kenneth N. Geluso, Russell A. Benedict, Francis L. Kock

Biology Faculty Publications

Information on seasonal activity and reproduction is presented for seven species of bats inhabiting east-central Nebraska (Eptesicus fuscus, Myotis septentrionalis, Nycticeius humeralis, Lasionycteris noctivagans, Lasiurus borealis, L. cinereus, and Pipistrellus subflavus). Early and late dates of capture show five species active in the state for longer periods than previously reported. During some years, E. fuscus and M. septentrionalis emerge from winter torpor in March and feed on insects. Some E. fuscus inhabiting a floodplain forest in summer use houses in nearby towns as hibernacula, and year-round use of buildings by E. fuscus is substantial compared to other species of bats. …

Snakes Of The United States And Canada: Natural History And Care In Captivity, Alan H. Savitzky

Biology Faculty Publications

No abstract provided.