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Genetic Resolution Of The Enigmatic Lesser Antillean Distribution Of The Frog Leptodactylus Validus (Anura, Leptodactylidae), Keneth Yanek, W. R. Heyer, Rafael O. De Sá Dec 2006

Genetic Resolution Of The Enigmatic Lesser Antillean Distribution Of The Frog Leptodactylus Validus (Anura, Leptodactylidae), Keneth Yanek, W. R. Heyer, Rafael O. De Sá

Biology Faculty Publications

Leptodactylus validus has 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 different island populations of L. validus, call data suggest the presence of a single species. Calls of L. pallidirostris from Venezuela and Brazil suggested that this taxon might be conspecific with L. validus. Sequence data from the 12S and 16S mt rDNA genes indicate that L. validus represents a single species throughout its distribution and is conspecific …


Karyotypes Of Eight Species Of Leptodactylus (Anura, Leptodactylidae) With A Description Of A New Karyotype For The Genus, Renata Cecília Amaro-Ghilardi, Gabriel Skuk, Rafael O. De Sá, Miguel Trefaut Rodrigues, Yatiyo Yonenaga-Yassuda Dec 2006

Karyotypes Of Eight Species Of Leptodactylus (Anura, Leptodactylidae) With A Description Of A New Karyotype For The Genus, Renata Cecília Amaro-Ghilardi, Gabriel Skuk, Rafael O. De Sá, Miguel Trefaut Rodrigues, Yatiyo Yonenaga-Yassuda

Biology Faculty Publications

Karyotypes of eight species of Leptodactylus (Anura, Leptodactylidae) with a description of a new karyotype for the genus. Eight species of the Neotropical genus Leptodactylus were karyologically studied: seven of them (L. gracilis, L. mystacinus, L. petersii, L. pustulatus, L. macrosternum, L. ocellatus, L. labyrinthicus) presented 2n=22 and L. silvanimbus showed a distinctive karyotype with 2n=24. Nucleolar organizer regions (Ag-NORs) were detected in two different pairs of chromosomes: pair 4 at the proximal region of the long arm of one individual of L. mystacinus from São Paulo state and of L. petersii; and …


Rana Ocellata Linnaeus, 1758 (Currently Leptodactylus Ocellatus; Amphibia, Anura): Proposed Conservation Of Usage Of The Specific Name By The Designation Of A Neotype, W. Ronald Heyer, Ulisses Caramaschi, Rafael O. De Sá Sep 2006

Rana Ocellata Linnaeus, 1758 (Currently Leptodactylus Ocellatus; Amphibia, Anura): Proposed Conservation Of Usage Of The Specific Name By The Designation Of A Neotype, W. Ronald Heyer, Ulisses Caramaschi, Rafael O. De Sá

Biology Faculty Publications

The purpose of this application, under Article 75.6 of the Code, is to conserve the usage of the specific name of Rana ocellata Linnaeus, 1758 for a species of leptodactylid frog from South America by the designation of a neotype. Prevailing usage of the name is threatened by the identity of the type specimen which is a different species than that which is currently known as Leptodactylus ocellatus. It is proposed that all name-bearing types be set aside and a neotype designated in accord with prevailing usage.


The Distress Calls Of Leptodactylus Chaquensis Cei, 1950 And Leptodactylus Elenae Heyer, 1978 (Anura: Leptodactylidae), José M. Padial, Rafael O. De Sá, Ignacio De La Riva Feb 2006

The Distress Calls Of Leptodactylus Chaquensis Cei, 1950 And Leptodactylus Elenae Heyer, 1978 (Anura: Leptodactylidae), José M. Padial, Rafael O. De Sá, Ignacio De La Riva

Biology Faculty Publications

We describe the distress calls of Leptodactylus chaquensis and Leptodactylus elenae. They each consist of a single, long, tonal sound with complex harmonic structure and complex frequency modulation. The distress calls of both species are different from their respective advertisement calls. Moreover, there are also clear interspecific differences. Harmonic frequencies in L. elenae are higher, there are fewer emphasized harmonics and the call is shorter and repeated at a higher rate (sometimes paired) than the call of L. chaquensis. Call duration, call rate, and position of the dominant harmonic change with the strength of the stimulus that the …


Phylogenetic Analyses Of Mtdna Sequences Reveal Three Cryptic Lineages In The Widespread Neotropical Frog Leptodactylus Fuscus (Schneider, 1799) (Anura, Leptodactylidae), Arley Camargo, Rafael O. De Sá, W. Ronald Heyer Feb 2006

Phylogenetic Analyses Of Mtdna Sequences Reveal Three Cryptic Lineages In The Widespread Neotropical Frog Leptodactylus Fuscus (Schneider, 1799) (Anura, Leptodactylidae), Arley Camargo, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Leptodactylus fuscus is a neotropical frog ranging from Panamá to Argentina, to the east of the Andes mountains, and also inhabiting Margarita, Trinidad, and the Tobago islands. We performed phylogenetic analyses of 12S rRNA, 16S rRNA, tRNA-Leu, and ND1 mitochondrial (mt) DNA sequences from specimens collected across the geographic distribution of L. fuscus to examine two alternative hypotheses: (i) L. fuscus is a single, widely distributed species, or (ii) L. fuscus is a species complex. We tested statistically for geographic association and partitioning of genetic variation among mtDNA clades. The mtDNA data supported the hypothesis of several cryptic species within …


Leptodactylus Fragilis (Brocchi): White-Lipped Thin-Toed Frog, Miriam M. Heyer, W. Ronald Heyer, Rafael O. De Sá Jan 2006

Leptodactylus Fragilis (Brocchi): White-Lipped Thin-Toed Frog, Miriam M. Heyer, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus fragilis are small. The head is longer than wide, and the hind limbs are moderately long (Table 1; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are laterally expanded and range from lightly gray speckled to darkly pigmented. Male snout is spatulate; female snout is rounded. Male forearms are not hypertrophied and males lack asperities on the thumbs and chest. The dorsum is spotted or blotched with dark markings, which are often chevron-shaped and sometimes confluent. The supratympanic fold is dark brown. A pair of dorsolateral folds …


Leptodactylus Fragilis, Mirriiam Muedeking Heyer, W. Ronald Heyer, Rafael O. De Sá Jan 2006

Leptodactylus Fragilis, Mirriiam Muedeking Heyer, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

Leptodactylus fragilis (Brocchi) White-lipped thin-toed frogs are characteristically defined according to their habitation and age. There is a diagnosis of different species group within Leptodactylus. It is furthermore described from different perspectives and discoveries such as its eggs and karyotype. The distribution of the frog is considered to be prominent occurring form Southernmost Teaxs throughout Mexico and Middle America expanding to Venezuela. The fossil fuel records and literature on Leptodactylus are slighly viewed before studying its nomenclatural history and rarity.


The Effects Of P53 Status And Egf On Timp-2 And Other Proteins Related To Migration In Human Glioblastoma Cell Cultures, Lisa M. Lint Jan 2006

The Effects Of P53 Status And Egf On Timp-2 And Other Proteins Related To Migration In Human Glioblastoma Cell Cultures, Lisa M. Lint

Honors Theses

The effects of epidermal growth factor (EGF) on proteins that have been implicated in the migration of the Grade IV brain tumor, glioblastoma multiforme, were investigated in this study. Differential expression levels of TIMP-2, MMP-2, and MT1-MMP in response to EGF treatment were compared by immunoprecipitation, and immunoblotting. This study involved two different cultured glioma cell lines, U87, which expresses wild-type p53, and T98, which has a mutation in the p53 gene, in order to determine if the status of the p53 tumor suppression gene is a factor in the regulation of proteins involved in this migration pathway. It was …


Development Of Proliferation Assays To Explore The Role Of Calcium Activated Potassium Channels In Cell Proliferation, Sean Foster Jan 2006

Development Of Proliferation Assays To Explore The Role Of Calcium Activated Potassium Channels In Cell Proliferation, Sean Foster

Honors Theses

Due to the large variety of Kchannel families implicated in cancer cell proliferation, it is desirable to develop techniques capable of quickly and reliably screening a variety of potential channels for a role in proliferation. While there are many established cell counting procedures, the time-consuming nature of such protocols limits their usefulness in broadly identifying particular channels in uncharacterized cell lines. For this reason, a primary goal of the present research was the development of techniques capable of implicating particular ion channels in proliferation with both qualitative and quantitative data. Once this goal was accomplished, the project sought …


The Effect Of Tgf-B And Egf On Mmp-2 Activation And Mt1-Mmp Phosphorylation In U87mg And T98g Human Glioma Cells, Jacquelyn B. Knupp Jan 2006

The Effect Of Tgf-B And Egf On Mmp-2 Activation And Mt1-Mmp Phosphorylation In U87mg And T98g Human Glioma Cells, Jacquelyn B. Knupp

Honors Theses

Glioblastoma multiforme (GBM), a high-grade, malignant brain tumor of astrocyte origin, invades normal brain tissue and most often results in death ofthe patient withinayearofdiagnosis. In order to invade the surrounding tissue and thereby metastasize, these tumor cells must migrate through the extracellular matrix. The pmpose ofthis research project is to investigate the family ofmatrix metalloproteinases responsible for extracellular degradation. Specifically, this investigation looks at MMP-2 activation via MT 1-MMP and the possible importance of phosphorylation of the tyrosine residue on the cytoplasmic tail of MTl-MMP. U87wildtypegliomacellsaswellasT98 p53 mutant glioma cells were treated with transforming growth factor beta (TGF-P). Preliminary results …


The Presence, Prevalence And Antibiotic Resistance Of Microbes In The Pamunkey River Basin, Christina Mcdowell Jan 2006

The Presence, Prevalence And Antibiotic Resistance Of Microbes In The Pamunkey River Basin, Christina Mcdowell

Honors Theses

This project examined the presence, prevalence and antibiotic resistance of Coliforms (mainly Escherichia coli), Staph/occocus aureus, fecal Streptococcus, andEnterobacteriacae found in the water samples taken from three selected sites on the North Anna, South Anna, and Little Rivers of the Pamunkey River Basin. The diversity and concentration of the microbes isolated from these sites was evaluated in late January and late March allowing for a comparison of the occurrence of microbes at different times and between the different sites. Over the course of two months the concentration of colonies increased based on colony counts from Nutrient agar. The rate of …


The Amphibian Tree Of Life, Darrel R. Frost, Taran Grant, Julián Faivovich, Raoul H. Bain, Alexander Haas, Célio F.B. Haddad, Rafael O. De Sá Jan 2006

The Amphibian Tree Of Life, Darrel R. Frost, Taran Grant, Julián Faivovich, Raoul H. Bain, Alexander Haas, Célio F.B. Haddad, Rafael O. De Sá

Biology Faculty Publications

The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit H1 (12S and 16S ribosomal RNA and tRNAValine genes, ø 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, …