Digital Commons Network^™

Muellerius Capillaris Dominates The Lungworm Community Of Bighorn Sheep At The National Bison Range, Montana, Vanessa O. Ezenwa, Alicia M. Hines, Elizabeth A. Archie, Eric P. Hoberg, Ingrid M. Asmundsson, John T. Hogg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Lungworm infections are common among bighorn sheep (Ovis canadensis) in North America, and the predominant species reported are Protostrongylus stilesi and P. rushi. The only records of another lungworm species, Muellerius capillaris, infecting bighorns come from South Dakota, USA. At the National Bison Range (NBR), Montana, USA we found that across six sampling periods, 100% of wild bighorn sheep surveyed were passing first-stage dorsal-spined larvae (DSL) which appeared to be consistent with M. capillaris. By contrast, only 39%or fewer sheep were passing Protostrongylus larvae. Using molecular techniques, we positively identified the DSL from the NBR …

How Specialists Can Be Generalists: Resolving The "Parasite Paradox" And Implications For Emerging Infectious Disease, Salvatore J. Agosta, Niklas Janz, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The parasite paradox arises from the dual observations that parasites (broadly construed, including phytophagous insects) are resource specialists with restricted host ranges, and yet shifts onto relatively unrelated hosts are common in the phylogenetic diversification of parasite lineages and directly observable in ecological time. We synthesize the emerging solution to this paradox: phenotypic flexibility and phylogenetic conservatism in traits related to resource use, grouped under the term ecological fitting, provide substantial opportunities for rapid host switching in changing environments, in the absence of the evolution of novel host-utilization capabilities. We discuss mechanisms behind ecological fitting, its implications for defining specialists …

First Report Of Viral Pathogens Wssv And Ihhnv In Argentine Crustaceans [Note], Sergio Roberto Martorelli, Robin M. Overstreet, Jean A. Jovanovich Alvillar

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The pathogenic penaeid shrimp viruses white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) are reported for the first time from Argentina. They both occurred in wild crustaceans in Bahia Blanca Estuary, with WSSV detected by polymerase chain reaction (pCR) or real time quantitative pCR (qpCR) methods as infecting samples as high as 56% of the penaeid Artemesia longinaris Bate, 1888, 67% of the grapsoid Cyrtograpsus angulatus dana, 1851, and 40% of the introduced palaemonid Palaemon macrodactylus Rathbun, 1902. The highest detected copy number was 39,600 copies/μg dNA. IHHNV was tested for using pCR in …

How Birds Combat Ectoparasites, Dale H. Clayton, Jennifer A. H. Koop, Christopher W. Harbison, Brett R. Moyer, Sarah E. Bush

Harold W. Manter Laboratory of Parasitology: Library Materials

Birds are plagued by an impressive diversity of ectoparasites, ranging from feather-feeding lice, to feather-degrading bacteria. Many of these ectoparasites have severe negative effects on host fitness. It is therefore not surprising that selection on birds has favored a variety of possible adaptations for dealing with ectoparasites. The functional significance of some of these defenses has been well documented. Others have barely been studied, much less tested rigorously. In this article we review the evidence--or lack thereof--for many of the purported mechanisms birds have for dealing with ectoparasites. We concentrate on features of the plumage and its components, as well …

The Interplay Between Host Cells And The Human Pathogen Trypanosoma Cruzi: Role Of Toll-Like Receptors, Lilian Lie Nohara

Open Access Theses & Dissertations

The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected infectious disease that is becoming a world health concern. This obligate intracellular parasite employs a diversity of molecules and strategies to successfully invade a wide variety of mammalian cells and modulate host immune responses, which are essential features for completion of its life cycle in the host. The major plasma membrane antigens of T. cruzi infective trypomastigote forms are glycosylphosphatidylinositol (tGPI)-anchored mucin-like glycoproteins. Although previous studies demonstrated that the proinflammatory responses induced by tGPIs are mediated by Toll-like receptor (TLR) 2, the involvement of other TLRs …

The Danger Signal Adenosine Induces Persistence Of Chlamydial Infection Through Stimulation Of A2b Receptors, Matthew A. Pettengill, Verissa W. Lam, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Infections with intracellular bacteria such as chlamydiae affect the majority of the world population. Infected tissue inflammation and granuloma formation help contain the short-term expansion of the invading pathogen, leading also to local tissue damage and hypoxia. However, the effects of key aspects of damaged inflamed tissues and hypoxia on continued infection with intracellular bacteria remain unknown. We find that development of Chlamydia trachomatis is reversibly retarded by prolonged exposure of infected cells to extracellular adenosine, a hallmark of hypoxia and advanced inflammation. In epithelial cells, this effect was mediated by the A2b adenosine receptor, unique in the adenosine receptor …

Tc17 Cd8 T Cells: Functional Plasticity And Subset Diversity, Adam J. Adler

UCHC Articles - Research

L-17-secreting CD8 T cells (Tc17) have been described in several settings, but little is known regarding their functional characteristics. While Tc1 cells produced IFN-γ and efficiently killed targets, Tc17 cells lacked lytic function in vitro. Interestingly, the small numbers of IFN-γ-positive or IL-17/IFN-γ-double-positive cells generated under Tc17 conditions also lacked lytic activity and expressed a similar pattern of cell surface proteins to IL-17-producing cells. As is the case for Th17 (CD4) cells, STAT3 is important for Tc17 polarization, both in vitro and in vivo. Adoptive transfer of highly purified, Ag-specific IL-17-secreting Tc17 cells into Ag-bearing hosts resulted in near complete …

Environmental Implications Of Francisella Tularensis Biofilms, Jeffrey J. Margolis '00

Doctoral Dissertations

Francisella tularensis survives in one of the widest environmental ranges of any pathogen. Numerous mammals and arthropod vectors are infected by this highly virulent organism. How this zoonotic pathogen persists outside of its many hosts remains unexplored. We aimed to examine how F. tularensis interacts with environmental surfaces, and hypothesized that biofilm formation may enable survival of this organism in nature. By understanding the role these surface-attached bacterial communities play in F. tularensis ecology, we hope to gain insight into the mechanisms of environmental persistence and transmission of this pathogen.

We identify chitin as a potential non-host niche for F. …

Common Genetic Variation And The Control Of Hiv-1 In Humans, Jacques Fellay, Dongliang Ge, Kevin V. Shianna, Sara Colombo, Bruno Ledergerber, Elizabeth T. Cirulli, Thomas J. Urban, Kunlin Zhang, Curtis Gumbs, Jason P. Smith, Antonella Castagna, Alessandro Cozzi-Lepri, Andrea De Luca, Philippa Easterbrook, Huldrych F. Gunthard, Simon Mallal, Cristina Mussini, Judith Dalmau, Javier Martinez-Picado, Jose M. Miro, Niels Obel, Steven M. Wolinsky, Jeremy J. Martinson, Roger Detels, Joseph Margolick, Lisa Jacobson, Patrick Descombes, Stylianos E. Antonarakis, Jacques S. Beckmann, Stephen J. O'Brien, Norman L. Letvin, Andrew J. Mcmichael, Barton F. Haynes, Mary Carrington, Sheng Feng, Amalio Telenti, David B. Goldstein, Niaid Center For Hiv/Aids Vaccine Immunology (Chavi)

Biology Faculty Articles

To extend the understanding of host genetic determinants of HIV-1 control, we performed a genome-wide association study in a cohort of 2,554 infected Caucasian subjects. The study was powered to detect common genetic variants explaining down to 1.3% of the variability in viral load at set point. We provide overwhelming confirmation of three associations previously reported in a genome-wide study and show further independent effects of both common and rare variants in the Major Histocompatibility Complex region (MHC). We also examined the polymorphisms reported in previous candidate gene studies and fail to support a role for any variant outside of …

Inactivation Of The Fliy Gene Encoding A Flagellar Motor Switch Protein Attenuates Mobility And Virulence Of Leptospira Interrogans Strain Lai, Sumei Liao, Ai-Hua Sun, David M. Ojcius, Senlin Wu, Jinfang Zhao, Jie Yan

All Dugoni School of Dentistry Faculty Articles

Background: Pathogenic Leptospira species cause leptospirosis, a zoonotic disease of global importance. The spirochete displays active rotative mobility which may contribute to invasion and diffusion of the pathogen in hosts. FliY is a flagellar motor switch protein that controls flagellar motor direction in other microbes, but its role in Leptospira, and paricularly in pathogenicity remains unknown.

Results: A suicide plasmid for the fliY gene of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai that was disrupted by inserting the ampicillin resistance gene (bla) was constructed, and the inactivation of fliY gene in a mutant (fliY-) was confirmed by PCR and …

Community Structure And Seasonal Dynamics Of Dactylogyrus Spp. (Monogenea) On The Fathead Minnow (Pimephales Promelas) From The Salt Valley Watershed, Lancaster County, Nebraska, Alaine Knipes, John J. Janovy Jr.

John J. Janovy, Jr. Publications

The gill monogene communities of Pimephales promelas (fathead minnow) in three distinct sites on converging streams were investigated from 2004 to 2006 in three different seasons. Thirty collections of P. promelas were made in southeastern Nebraska along three converging tributaries: Elk Creek (40.88534°N, 96.83366°W), West Oak Creek (40.9082°N, 96.81432°W), and Oak Creek (40.91402°N, 96.770583°W), Lancaster County, Nebraska. In all, 103 P. promelas were collected from Elk Creek, 115 from West Oak Creek, and 78 from Oak Creek and examined for gill monogenes. Among the P. promelas collected, 93.5% were infected with up to three species of Dactylogyrus, including Dactylogyrus …

Exploring T. Brucei Hexokinase Biology: Localization And Inhibition Studies, Todd Lyda

All Dissertations

Trypanosoma brucei, the causative agent of the disease African sleeping sickness
in humans and nagana in animals, is a scourge of sub-Saharan Africa. There is a
desperate need for more efficacious therapies for the disease; here we describe research
validating T. brucei hexokinase 1 (TbHK1) as a drug therapeutic target for T. brucei
infection and the identification and characterization of novel inhibitors of the enzyme by
both low throughput and high throughput means. Additionally this thesis introduces
efforts at characterizing a second T. brucei hexokinase, focusing mostly on cell biology
and the determination of localization.
The small molecule quercetin (QCN) …

Synlophe Structure For Species Of Longistrongylus (Nematoda: Trichostrongyloidea), Abomasal Parasites Among Ungulates From Sub-Saharan Africa, With Comparisons To The Global Ostertagiine Fauna, Eric P. Hoberg, Arthur Abrams, Patricia A. Pilitt

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The synlophe, or system of longitudinal cuticular ridges characteristic of some trichostrongyloid nematodes, is examined in detail for 6 of 8 species in Longistrongylus (Ostertagiinae) that occur in ungulates across sub-Saharan Africa. Among the species of Longistrongylus examined, 5 are characterized by a tapering pattern laterally in the cervical zone (anterior to the esophageal-intestinal junction), which is largely consistent among multiple male and female specimens; in contrast, for Longistrongylus meyeri the lateral pattern is parallel. The synlophe is bilaterally symmetrical, with ridges extending from the base of the cephalic expansion to near the caudal extremity in males and females. Ridges …

Where Are The Parasites? [Letters], Susan J. Kutz, Andy P. Dobson, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

First paragraph:

The review by E. Post et al. ("Ecological dynamics across the Arctic associated with recent climate change," 11 September 2009, p. 1,355) paid little heed to parasites and other pathogens. The rapidly growing literature on parasites in arctic and subarctic ecosystems provides empirical and observational evidence that climate-linked changes have already occurred. The life cycle of the protostrongylid lungworm of muskoxen, Umingmakstrongylus pallikuukensis, has changed, and the range of that organism and the winter tick, Dermacentor albipictus, has expanded.

A Review Of The Lethal Spiny Lobster Virus Pav1 - Ten Years After Its Discovery, Donald C. Behringer, Mark J. Butler Iv, Jeffrey D. Shields

Biological Sciences Faculty Publications

In 1999, we discovered that juvenile Caribbean spiny lobsters (Panulirus argus) in the Florida Keys were infected with PaV1 (Panulirus argus virus 1), the first naturally occurring pathogenic virus reported from lobsters. The virus profoundly affects their biology and ecology. PaV1 is probably wide-spread in the Caribbean with confirmed infections from the United States (Florida), St Croix, Mexico, and Belize; and anecdotal reports from the Bahamas and Cuba. Mean prevalence in the Florida Keys has been stable since 1999 (5 - 8%), but has risen from 2.7% to 10.9% in Mexico (Puerto Morelos), the only other country where …

Methods And Compositions For Vaccnation Of Animals With Prrsv Antigens With Improved Immunogenicity, Israrul H. Ansari, Fernando A. Osorio, Asit K. Pattnaik,

School of Veterinary and Biomedical Sciences: Faculty Publications

Pigs challenged with hypoglycosylated variants of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) major surface protein GP5 exhibited increased production of PRRSV-neutralizing antibodies relative to the levels of neutralizing antibodies produced by pigs immunized with wild type (wt) or glycosylated GP5. This invention provides for methods of obtaining improved immune responses in pigs to PRRSV, compositions useful for obtaining the improved immune responses as well as isolated polynucleotides that encode hypoglycosylated variants of PRRSV major surface protein GP5.

Comparative Life Cycles And Life Histories Of North American Rhabdias Spp. (Nematoda: Rhabdiasidae): Lungworms From Snakes And Anurans, Gabriel J. Langford, John J. Janovy Jr.

John J. Janovy, Jr. Publications

The present study used experimental infections to compare the life cycles and life histories of 6 Rhabdias spp. infecting snakes and anurans. Free-living development of anuran lungworms was primarily limited to heterogonic reproduction, and females utilized matricidal endotoky exclusively, whereas snake lungworms primarily reproduced homogonically and, when heterogonic reproduction occurred, females used a combination of releasing eggs and matricidal endotoky. Infective snake lungworms survived for longer periods in fresh water compared to anuran worms. Infective anuran lungworms penetrated into the skin of frogs and toads; few infections resulted from per os infections. In contrast, snake lungworms were unable to penetrate …

Ccl3l1 And Hiv/Aids Susceptibility, Thomas J. Urban, Amy C. Weintrob, Jacques Fellay, Sara Colombo, Kevin V. Shianna, Curtis Gumbs, Margalida Rotger, Kimberly Pelak, Kristen K. Dang, Roger Detels, Jeremy J. Martinson, Stephen J. O'Brien, Norman L. Letvin, Andrew J. Mcmichael, Barton F. Haynes, Mary Carrington, Amalio Telenti, Nelson L. Michael, David B. Goldstein

Biology Faculty Articles

No abstract provided.

Eimeria Spp. (Apicomplexa: Eimeriidae) From The Plateau Pika, Ochotona Curzoniae, From Haibei Area, Qinghai Province, China, With The Description Of Two New Species, Yi-Fan Cao, Run-Roung Ye, Jian-Hua Wu, Jiang-Hui Bian, Donald W. Duszynski

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Fifty-two fecal samples from the Plateau pika, Ochotona curzoniae, collected in the Haibei Area, Qinghai Province, China, were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Five distinct morphotypes, all Eimeria species, were distinguished based on the structure of their sporulated oocysts. Three of these included Eimeria banffensis, Eimeria calentinei, and Eimeria cryptobarretti, all of which have been described previously from other Ochotona species. We also studied 2 morphotypes that we feel have sufficient qualitative and quantitative characters to distinguish them from all previously described species; herein, we identify them as putative new species. Eimeria qinghaiensis …

Inflammasome-Dependent Caspase-1 Activation In Cervical Epithelial Cells Stimulates Growth Of The Intracellular Pathogen Chlamydia Trachomatis, Ali A. Abdul-Sater, Evonne Koo, Georg Hacker, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Inflammasomes have been extensively characterized in monocytes and macrophages, but not in epithelial cells, which are the preferred host cells for many pathogens. Here we show that cervical epithelial cells express a functional inflammasome. Infection of the cells by Chlamydia trachomatis leads to activation of caspase-1, through a process requiring the NOD-like receptor family member NLRP3 and the inflammasome adaptor protein ASC. Secretion of newly synthesized virulence proteins from the chlamydial vacuole through a type III secretion apparatus results in efflux of K+ through glibenclamide-sensitive K+ channels, which in turn stimulates production of reactive oxygen species. Elevated levels of reactive …

Genetics And Pathogenesis Of Feline Infectious Peritonitis Virus, Meredith Brown, Jennifer L. Troyer, Jill Pecon-Slattery, M. Roelke-Parker, Stephen J. O'Brien

Biology Faculty Articles

Feline coronavirus (FCoV) is endemic in feral cat populations and cat colonies, frequently preceding outbreaks of fatal feline infectious peritonitis (FIP). FCoV exhibits 2 biotypes: the pathogenic disease and a benign infection with feline enteric coronavirus (FECV). Uncertainty remains regarding whether genetically distinctive avirulent and virulent forms coexist or whether an avirulent form mutates in vivo, causing FIP. To resolve these alternative hypotheses, we isolated viral sequences from FCoV-infected clinically healthy and sick cats (8 FIP cases and 48 FECV-asymptomatic animals); 735 sequences from 4 gene segments were generated and subjected to phylogenetic analyses. Viral sequences from healthy cats were …

An Iterative Strategy Combining Biophysical Criteria And Duration Hidden Markov) Models For Structural Predictions Of Chlamydia Trachomatis S66 Promoters, Ronna R. Mallios, David M. Ojcius, David H. Ardell

All Dugoni School of Dentistry Faculty Articles

Background: Promoter identification is a first step in the quest to explain gene regulation in bacteria. It has been demonstrated that the initiation of bacterial transcription depends upon the stability and topology of DNA in the promoter region as well as the binding affinity between the RNA polymerase σ-factor and promoter. However, promoter prediction algorithms to date have not explicitly used an ensemble of these factors as predictors. In addition, most promoter models have been trained on data from Escherichia coli. Although it has been shown that transcriptional mechanisms are similar among various bacteria, it is quite possible that the …

Sheep Updates 2009, Brown Besier, L. J. E. Karlsson, J. C. Greeff, A. C. Schlink, Mark Ferguson, Greg Lee, Sue Hatcher, Bruce Michael, Rob Woodgate, Darren Michael, Mandy Curnow, Julia Smith, John Young, Andrew Thompson, Chris Oldham

Sheep Updates

This session covers seven papers from different authors:

1. Scouring Management and Worm Control, Brown Besier, Department of Agriculture and Food, Western Australia

2.Breeding sheep for resistance to breech strike:- Selection results in WA, LJE Karlsson, JC Greeff & AC Schlink, Department of Agriculture and Food, Western Australia

3.Future Ewe - matching genetics to the production system, Mark Ferguson, Department of Agriculture and Food, Western Australia

4. Within-flock selection of ewes: opportunities for gains in reproduction, Greg Leeand Sue Hatcher, NSW Department of Primary Industries & Australian CRCforSheep Industry Innovation (Orange)

5. Managing Merinos …

American Society Of Parasitologists Newsletter, V. 31, No. 2, Summer 2009, Scott Lyell Gardner

American Society of Parasitologists: Newsletter

An issue of the American Society of Parasitologists' quarterly newsletter, also called the Journal of Parasitology Newsletter.

Lipid Targets Of The Antimalarial Trioxanes In Plasmodium Falciparum, Carmony Leah Hartwig

Biological Sciences Theses & Dissertations

Malaria is among the most debilitating diseases of man. The protozoan parasite, Plasmodium falciparum, causes over a million annual fatalities. The antimalarial trioxanes, exemplified by artemisinin, are among the few pharmaceuticals for which clinical resistance has not become widespread. Artemisinin is a naturally occurring sesquiterpene lactone, containing a unique endoperoxide pharmacophore. Despite extensive study, the precise antimalarial mechanism of action of trioxanes remains elusive. Heme iron-mediated cleavage of the endoperoxide within the parasite digestive vacuole is hypothesized to generate cytotoxic metabolites capable of alkylating heme and damaging cellular macromolecules. The hypothesis of this research is that the endoperoxide pharmacophore …

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

John J. Janovy, Jr. 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 …

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 …

Single-Amino-Acid Alterations In A Highly Conserved Central Region Of Vesicular Stomatitis Virus N Protein Differentially Affect The Viral Nucleocapsid Template Functions, Debasis Nayak, Debasis Panda, Subash C. Das, Ming Lou, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

The nucleocapsid protein (N) of vesicular stomatitis virus and other rhabdoviruses plays a central role in the assembly and template functions of the viral N-RNA complex. The crystal structure of the viral N-RNA complex suggests that the central region of the N protein interacts with the viral RNA. Sequence alignment of rhabdovirus N proteins revealed several highly conserved regions, one of which spanned residues 282 to 291 (GLSSKSPYSS) in the central region of the molecule. Alanine-scanning mutagenesis of this region suggested that replacement of the tyrosine residue at position 289 (Y289) with alanine resulted in an N-RNA template that is …

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.

John J. Janovy, Jr. 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 …