Biology Commons^™

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 …

The Status Of Leptodactylus Validus As A Single Taxon And Its Relationship To Letptodactylus Pallidirostris, Kenneth Christopher Yanek

Master's Theses

Leptodactylus validus exhibits an unusual distribution inhabiting Trinidad, Tobago, and the Lesser Antilles, but not the mainland of South America. This distribution is inconsistent with other distribution patterns observed for these islands. Although slight variation in adult morphology has been observed among the island populations, call data suggest the presence of a single species. Calls of Leptodactylus pallidirostris from Venezuela suggested that this taxon might be conspecific with L. validus. Herein sequence data from the 12S and 16S mt rRNA genes were collected and analyzed in order to address: 1.) whether more than one species is represented within L. validus, …

Distribución Geográfica De La Fauna De Anfibios Del Uruguay, Diego Nuñez, Raúl Maneyro, José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Datos precises sobre la distribución geográfica de los organismos de una región son necesarios y prerrequisito para entender las interrelaciones ecológicas entre las comunidades biológicas. Esta información también contribuye a entender el componente histórico de la región posibilitando la determinación de centros de origen y el establecimiento de patrones de diversidad (Ron, 2000), así mismo posibilita realizar inferencias acerca de los mecanismos de especiación en los diferentes grupos zoológicos (Bridarolli & Di Tada, 1994).

La distribución geográfica de los anfibios en Uruguay ha sido parcialmente reportada (Achaval & Olmos, 1997; Langone, 1995; Maneyro et al, 1995; Maneyro & Langone, 2001). …

A Survey Of Antibiotic Resistance Among Coliform Bacteria Isolated From The Missouri River, Sara E. Mcdonnell, Amy M. Treonis

Biology Faculty Publications

The prevalence of antibiotic resistant microorganisms in the environment is not well known but could represent a challenge to maintaining public health in the future. Fecal waste from livestock facilities, where antibiotics are routinely used, is recognized as a significant source of pollution to surface waters in the United States. We collected water from the Missouri River across a winter to spring seasonal change in order to survey the density of coliform bacteria. We tested bacterial isolates for resistance to penicillin, tetracycline, ampicillin, erythromycin, and ciprofloxacin. Coliform density in Missouri River water generally was high throughout the study (0-405 cfu …

Características Histológicas De La Tumefacción Frontal De Melanophryniscus (Amphibia: Anura: Bufonidae), Daniel E. Naya, José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Se analizó la histología tegumentaria de la región cefálica en seis especies del género Melanophryniscus, pertenecientes a los grupos stelzneri (4) y tumifrons (2), con el objetivo de esclarecer la estructura de la tumefacción frontal y su posible función. Las características generales de la histología del grupo stelzneri, coincidieron con las descripciones tegumentarias existentes para el género. Sin embargo, la región cefálica frontal en las dos especies del grupo tumifrons muestran cambios histológicos correlacionados a la tumefacción frontal. Esta estructura presenta una organización similar a otras macroglándulas presentes en la dermis de anuros (e.g., parotoides, paracnémicas), y por tanto se …

On The Engimatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Leptodactylidae), W. R. Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982, 518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate …

Type Of Muscle Present In Adult Amphibian Lymphatic Heart Based On The Dna Sequence Of The Myosin Heavy Chain, Maribeth Morral

Honors Theses

Water and plasma are forced from the capillaries into the interstitial fluid. This fluid is useful l as it moves materials between cells. Most of this fluid is collected in the capillarie of a second circulatory system, the lymphatic system. The first function of such a system is returning the excess blood plasma, now o as lymph, that has accumulated in the tissue spaces. Lymph flows from small lymph capillaries into lymph vessels that are similar to veins in having valves that prevent back flow. Lymph vessels collect to lymph nodes, lymph organs, or to the cardiovascular system at the …

Blackwell Publishing Ltd. Chondrocranial, Hyobranchial And Internal Oral Morphology In Larvae Of The Basal Bufonid Genus Melanophryniscus (Amphibia: Anura), Peter M. Larson, Rafael O. De Sá, Diego Arrieta

Biology Faculty Publications

Melanophryniscus is a genus of small toads inhabiting the southern portion of South America. This genus is considered basal within the family Bufonidae. Data on larval chondrocranial morphology do not exist for the genus and larval internal oral anatomy has only been described for a single species. Here, we describe chondrocranial and internal oral morphology in Melanophryniscus montevidensis, M. orejasmirandai and M. sanmartini. Chondrocranial morphology is similar among the species examined. Comparisons with other bufonids and with outgroup taxa suggest that the following chondrocranial characters may represent synapomorphies for the Bufonidae: free (or absent) ceratobranchial IV, a reduced …

Acalypha Deamii : Distribution East Of The Appalachians And Comparative Studies Of Reproductive Anatomy, Patricia A. Truman

Master's Theses

Acalypha deamii (Euphorbiaceae), once thought restricted to flood plains of the Ohio and mid-Mississippi River systems, is now documented from similar habitats in Virginia, Maryland, and West Virginia along the James, Potomac, Rappahannock, Roanoke (Staunton), and Shenandoah rivers. This species is recognized by two-carpellate gynoecia, large seeds, and the routine occurrence of allomorphic flowers and fruits, features sporadically found within this large genus. In addition to documenting the newly recognized range extension of Acalypha deamii, this thesis also investigates the nature of its allomorphic reproductive structures. Staminate, pistillate, fruiting, and allomorphic reproductive structures of Acalypha deamii and a closely related …

The Tadpole Of Phrynobatrachus Mababiensis Fitzsimons, 1932 (Anura, Ranidae, Petropedetinae), Rafael O. De Sá, Alan Channing

Biology Faculty Publications

The puddle frog genus Phrynobatrachus Günther, 1862 comprises about 64 currently recognized species (Frost, 1985). Of these, only the tadpoles of P. natalensis (Smith, 1849) (Power, 1927; Channing, 2001), P. guineensis Guibé & Lamotte, 1961(Rödel,1998) and P. alticola Guibé & Lamotte, 1961 (Rödel & Ernst, 2002) have been described. Phrynobatrachus mababiensis FitzSimons, 1932 (Dwarf Puddle frog, Wager, 1986; Mababe River frog, Frank & Ramus, 1996) is a small frog that usually calls from low in thick vegetation on flooded terrains close to the water. Very little has been published about the biology of this species. Passmore & Carruthers (1979) reported …

Polystomatidae (Monogenea) Of Southern African Anura: Eupolystoma Vanasi N. Sp. Parasitic In Schismaderma Carens (Smith), Louis H. Du Preez, Richard C. Tinsley, Rafael O. De Sá

Biology Faculty Publications

Eupolystoma vanasi is described as a new species of the Polystomatidae parasitic in the urinary bladder of Schismaderma carens in Northern Province and KwaZulu-Natal Province, South Africa. This is the third Eupolystoma species described from Africa and the first polystomatid from Schismaderma, an anuran genus that is primitive with respect to the other African bufonids in which Eupolystoma has been recorded. The species is distinguished by body size (this is the largest Eupolystoma known; mean length of adults 6 mm), by genital spine number (4 in comparison with 6-9 in other species), marginal hooklet length (greater than in other …

Leptodactylus Mystacinus, M. M. Heyer, W. R. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus mystacinus are of moderate size, the head is as wide as long, and the hind limbs are moderately short (see Table; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are not visible externally or at best are weakly expanded laterally and slightly darker than female throats. Male snouts are more spatulate than those of females. Male forearms are not hypertrophied. Males lack asperities on the thumbs and chest. One or two pairs of dorsolateral folds (indicated by dark/light outlining in indifferently preserved specimens) are present: one …

Fecal Coliforms And Antibiotic Resistance Of Tuckahoe Creek, Catherine C. Parker

Honors Theses

The Tuckahoe Creek has been classified impaired by the Virginia Department of Environmental Quality (DEQ) indicating that one of the following parameters exceed the accepted limits: pH, temperature, dissolved oxygen (DO), phosphates, nitrates, and concentration of fecal coliforms. Throughout the course of this study, two selected sites have been monitored monthly in order to measure these parameters. Route 288 is located near a construction site, and Route 621 is near Sycamore Creek Golf Course in a more rural area. The results from this study have shown that the fecal coliforms have been uniformly within the set legal limit of 1,000 …

The Tadpole Of Proceratophrys Avelinoi (Anura: Leptodactylidae), Rafael O. De Sá, José A. Langone

Biology Faculty Publications

The genus Proceratoprhrys is poorly known. It consists of 14 currently recognized species (Frost, 2000) of medium-sized frogs distributed from northeastern Argentina and Paraguay to southeast Amazonia (Rondonia State), eastern and southern Brazil. Proceratophrys avelinoi was described from Misiones, Argentina (Mercadal de Barrio and Barrio, 1993). The larval stage of this species is unknown. Herein, we describe the tadpole and the characteristics of the internal oral anatomy of P avelinoi using scanning electron micros- copy (SEM).

A Mitochondrial Dna Phylogeny Of The Leptodactylus Fuscus Species-Complex (Leptodactylidae: Anura, Arley Camargo

Master's Theses

Leptodactylus fuscus is a broadly distributed frog species in the Neotropical region. Previous allozymic evidence supported the hypothesis of L. fuscus as a composite of several species. However, morphological and advertisement call data supported the hypothesis of a single-species taxon. These competing hypotheses were evaluated using cladistic analyses of mitochondrial DNA sequences. Fragments of 12S rRNA, 16S rRNA, and ND1 protein-coding genes from 17 populations were sequenced. Phylogenetic analyses were performed using: maximum parsimony, maximum likelihood, and Bayesian analysis. Data sets were analyzed separately and combined. Analyses of the combined data set show four exclusive clades of L. fuscus: …

Leptodactylus Silvanimbus, W. R. Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Adult Leptodactylus silvanimhus are of moderate sized, the head is about as wide as long, and the hind limbs are moderate in length (see Table; also see Heyer and Thompson 2000 for definitions of adult size and leg length categories for Leptodacrylus). The male vocal sac is single and internal. Male forearms are hypertrophied in larger individuals. Adult males have two black thumb spines on each hand and lack chest spines. Individuals lack dorsolateral folds. The toe tips are narrow, not expanded. Females have weakly developed lateral toe fringes and males either have lateral toe ridges or weakly developed fringes. …

Complement Resistance In Agrobacterium Tumefaciens Isolates, Michael E. Mccormick

Honors Theses

The word "pathogen" ofen brings to mind morose images and other words such as "illness," "malaria," and "outbreak": words associated with animal pathogens, in particular, the ones that make us humans sick. However, some pathogens also affect another major kingdom, plants, and one of the more devastating pathogens to the plant kingdom is the bacteria Agrobacterium tumefaciens. This organism has a Type IV Secretion System that allows it to transfer a piece of t-DNA into the host cell; this DNA integrates into the eukaryotic genome and establishes in ction by utilizing the host's transcription machinery. This unique and effective means …

Storm-Related Suspended Particulate Matter In Little Westham Creek, John R. Jordan

Master's Theses

Properties of a watershed regulate the amount of suspended particulate matter (SPM) in a stream. The present study examined relationships between storm-related SPM and impervious area and tree cover in the suburban watershed of Little Westham Creek, Richmond, Virginia during Summer and early Fall, 1999. SPM concentration, SPM discharge, and turbidity due to clay, silt and sand, and the areas of impervious surface and tree stand cover in the watershed were measured at three sites. SPM concentration, SPM discharge, and turbidity due to clay were greater upstream than downstream. The percentages of watershed area covered by impervious surfaces and tree …

A Quantitative Histological Evaluation Of Articular Cartilage And Regenerated Tissue From A Stress-Shielded In Vivo Model, Jeremy Matthew Kupsco

Master's Theses

Cartilage does not normally repair lesions. Cartilage induced to regenerate experimentally degenerates quickly, perhaps because stresses of articulation do not allow normal extracellular matrix to develop. I examined normal cartilage from dogs, pigs, rabbits, and humans, and canine patellar tissue regenerated in a stress-shielded environment. SEM of canine cartilage after trypsin digestion revealed meshworks of fibrils oriented with a bias normal to the surface in the deep zone, random in the middle zone, and parallel to the surface in the superficial zone. SEM after freeze-fracture revealed tubules of fibrils within the deep zone. I found no evidence of collagen arcades. …

Characterization Of A Non-Ribosomal Peptide From Agrobacterium Tumefaciens, Graham Strub

Honors Theses

The current efforts underway to sequence the genome of Agrobacterium tumefaciens have led to the discovery of a large region of DNA (52kb) with a strong homology to several polyketide synthetase genes. This was a matter of great interest to the Agrobacterium project; no current literature documents the production of a polyketide or non:iibosomal peptide from Agrobacterium. Furthermore, the multi-domain enzymes coded by these polyketide synthetase genes in other bacterial species are responsible for synthesizing several toxins, many which act as antibiotic agents {8, 9, 12, 16). This was also of great interest, since Agrobacterium is not known to produce …

The Role Of Matrix Metalloproteinase-2 In Glioma Invasion, Nicole Danielle Sauers

Master's Theses

Overexpression of matrix metalloproteinase 2, MMP-2, is correlated with highgrade gliomas in vivo. The purpose of this study was to investigate whether MMP-2 overexpression in glioma cell lines leads to increased invasion of glioma cells in vitro. The entire MMP-2 gene was isolated from U87, a glioma cell line known to have high expression of wild-type MMP-2. This :tvIMP-2 gene was inserted in a sense and antisense orientation into pCR3 .1 vectors with a CMV promoter to ensure high levels of expression. Glioma cell lines were transfected with the sense and antisense constructs, as well as the pCR3.l vector alone …

Chondrocranium And Visceral Skeleton Of Atelopus Tricolor And Atelophryniscus Chrysophorus, E O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium , cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations.

Invasion Of Mouse Fibroblasts And Macrophages By Human Isolates Of Agrobacterium, Karmon Leigh Kriechbaum

Honors Theses

In the past few decades there has been growing evidence that species of Agrobacterium can be opportunistic animal pathogens. One of these species is Agrobacterium tumefaciens, which for years has been studied as a plant pathogen. The results of one published experiment suggested that an Agrobacterium toxin could kill mice (12). Other strong evidence for Agrobacterium as an opportunistic human pathogen is the over fifty published clinical cases in which humans were infected by Agrobacterium species (3, 13-25). In almost all of these cases the patient was immunocompromised in some way and they often had an invasive procedure such as …

Do Timing And Pattern Of Myogenesis Correlate With Life History Mode In Anurans?, Matthew T. Smetanick, Rafael O. De Sá, Gary P. Radice

Biology Faculty Publications

The timing and pattern of myogenesis varies among anurans that have been studied and the different pat- terns may provide useful phylogenetic information. Specific myogenic markers have been described (Muntz, 1975; Kielbowna, 1981; Boudjelida & Muntz, 1987; Radice et al., 1989) and they can provide infor- mation on evolutionary changes for closely related lineages within a clade. For example, we previously com- pared first appearance of a muscle-specific protein, first twitch of axial muscle, onset of multinucleation within axial myotome, and first heartbeat in two pipid genera (Smetanick et al., 1999). We found that although the timing of myogenesis differed, …

Los Anfibios Del Monumento Natural Barro Colorado, Parque Nacional Soberania Y Areas Adyacentes, Rafael O. De Sá

Biology Faculty Publications

This book focuses on the batrachofauna of Barro Colorado Nature Monument. Soberania National Park and adjacent areas. It complements other recent publications on Neotropical amphibians such as those by Rodriguez and Duellman ( 1994) on Peru, Achaval and Olmos (1995) on Uruguay, and Meyer and Foster (1996) on Belize. The goal of these books is to reach a wider audience than the more technical batrachofaunal summaries-e.g., Frogs of Boracéia (Heyer 1990). Amphibians of Argentina (Cei 1985), and Frogs of the Genus Eleutherodactylus in Western Ecuador (Lynch and Duellman 1997). These geographically focused guides are especially useful to students, amateur biologists, …

An Ulstrastructural Study Of Acetabularia Acetabulum, Rachel Vangilder

Master's Theses

Calcification within the cell and the cell wall Acetabularia acetabulum, a large single cell alga, is examined through an ultrastructural investigation, electron diffraction, and an elemental analysis. These methods suggest that amorphous calcium carbonate is located adjacent to and within the cell wall. The location of the crystals within and directly outside the cell wall suggests the calcium is obtained from the surrounding environment. Fibrillar structures are seen through SEM in areas where calcification is occurring. This fibrillar material appears to serve as the organic matrix where calcification initiates. Intracellularly electron dense materials is seen in the chloroplasts. This …

Los Coquís De Puerto Rico: Su Historia Natural Y Conservación, Rafael O. De Sá

Biology Faculty Publications

As the title indicates, this well-illustrated (115 photographs and 76 illustrations) book summarizes the current knowledge about the natural history of the 16 species of Eleutherodactylus inhabiting Puerto Rico. The book consists of eight chapters (including the epilogue) and it is clearly stated that it was written to serve both the scientific community and the nonspecialist reader. The goal of bridging these two audiences is ambitious and usually difficult; however, the book has probably accomplished this goal. The technical reader, i.e., students and professional herpetologists, will find a good summary of data and enough information to continue reading with interest. …

Scientific Investigation Of The Plant Pathogen Agrobacterium Tumefaciens, Casey M. Flanagan, Christopher B. Crowell Ii, Bryan P. Markelz

Honors Theses

A. tumefaciensis a plant pathogen and causative agent of Crown Gall Disease, an ailment that results in the development of tumors in plants. It is a unique organism in that it is the only known non-viral pathogen that transfers its DNA into the host cell. Consequently, the majority of the research conducted on A. tumefaciensinvestigates its mechanism of infection. However, A. tumefaciensis also rare to the bacterial world in that its genome is comprised of two chromosomes: one circular and one linear. Most other bacteria only have one circular chromosome. This area of research has been grossly overlooked and therefore …

Characterizing The Role Of Mapk Phosphates In Plants, Laura Asakura

Honors Theses

Mitogen Activated Protein Kinase (MAPK) pathways e ubiquitous ongst eukaryotes, involved in the signal transduction of various external stimuli to the nucleus. In plants, only MAPK pathways related to pathogen- and stress-related responses have been identified. It has been proposed that another MAPK pathway exists in plants, one that is similar to animal MAPK pathways and postulated to connect the regulation of cell growth and the actions of hormones auxin, cytokinin, and gibberellin. In order to establish whether a link exists between the MAPK pathway and hormone signaling in plants, the role of MAPK phosphatases (MKP) on hormone signaling was …

Comparing The Tadpoles Of Hyla Geographica And Hyla Semilineata, Anne D'Heursel, Rafael O. De Sá

Biology Faculty Publications

External morphology, internal oral anatomy, and chondrocranial anatomy were examined for tadpoles of Hyla geographica from the Amazon rainforest, Brazil, and Hyla semilineata from the Atlantic rainforest, Brazil. Here, we provide morphological larval data to help diagnose these closely related species. Scanning electron microscopy analysis of buccal morphology showed the most distinctive features between these species: the distance between the lingual papillae in the buccal floor of H. geographica is three times greater than that distance in H. semilineata, and the relative size of the lingual papillae in H. geographica is less than half their size in H. semilineata. Although …