Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup...

Experiments are described in which eggs of Rana species were treated prior to insemination with antisera prepared against oviducal materials of Rana, Bufo, and Ambystoma species. Three types of treatment with antisera were employed. Eggs of Rana pipiens and R. clamitans were treated with antisera against materials prepared from whole oviducts, or from upper and lower segments of oviducts, of R....

ii I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. Abstract Exposure of cells to environmental or chemical stressors will initiate the heat shock response, which is mediated by heat shock proteins. Heat shock...

Ecologists have often suggested that the presence of pathogens that differentially affect interacting species may affect the outcome of interactions, yet few experimental studies have documented pathogen-mediated interactions using a natural host–parasite system. We studied the effects of a pathogenic water mold, Saprolegnia ferax, on competitive interactions between the Cascades frog Rana casc...

In Neotropical streams, benthic sediment affects community structure and may impose energetic costs for some species yet to be a resource for others. This study tested the hypothesis that removal of benthic sediment through ingestion by Rana palmipes (Ranidae), a detritivorous tadpole, facilitated the growth of Ancistrus triradiatus (Loricariidae), an algivorous armored catfish. We hypothesized...

True frogs of the genus Rana are widely used as model organisms in studies of development, genetics, physiology, ecology, behavior, and evolution. Comparative studies among the more than 100 species of Rana rely on an understanding of the evolutionary history and patterns of diversification of the group. We estimate a well-resolved, time-calibrated phylogeny from sequences of six nuclear and th...