Life Sciences Commons^™

High Local Diversity Of Trypanosoma In A Common Bat Species, And Implications For The Biogeography And Taxonomy Of The T. Cruzi Clade, Veronika M. Cottontail, Elisabeth K. V. Kalko, Iain Cottontail, Nele Wellinghausen, Marco Tschapka, Susan L. Perkins, C. Miguel Pinto

Publications and Research

The Trypanosoma cruzi clade is a group of parasites that comprises T. cruzi sensu lato and its closest relatives. Although several species have been confirmed phylogenetically to belong to this clade, it is uncertain how many more species can be expected to belong into this group. Here, we present the results of a survey of trypanosome parasites of the bat Artibeus jamaicensis from the Panama´ Canal Zone, an important seed disperser. Using a genealogical species delimitation approach, the Poisson tree processes (PTP), we tentatively identified five species of trypanosomes – all belonging to the T. cruzi clade. A small monophyletic …

Dynamically-Expressed Prion-Like Proteins Form A Cuticle In The Pharynx Of Caenorhabditis Elegans, Julia B. George-Raizen, Keith R. Shockley, Nicholas F. Trojanowski, Annesia L. Lamb, David M. Raizen

Publications and Research

In molting animals, a cuticular extracellular matrix forms the first barrier to infection and other environmental insults. In the nematode Caenorhabditis elegans there are two types of cuticle: a wellstudied collagenous cuticle lines the body, and a poorly-understood chitinous cuticle lines the pharynx. In the posterior end of the pharynx is the grinder, a tooth-like cuticular specialization that crushes food prior to transport to the intestine for digestion. We here show that the grinder increases in size only during the molt. To gain molecular insight into the structure of the grinder and pharyngeal cuticle, we performed a microarray analysis to …

Nesting Behaviour Influences Species-Specific Gas Exchange Across Avian Eggshells, Steven J. Portugal, Golo Maurer, Gavin H. Thomas, Mark E. Hauber, Tomáš Grim, Phillip Cassey

Publications and Research

Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. …

Review: Zinc’S Functional Significance In The Vertebrate Retina, Harris Ripps, Richard L. Chappell

Publications and Research

This review covers a broad range of topics related to the actions of zinc on the cells of the vertebrate retina. Much of this review relies on studies in which zinc was applied exogenously, and therefore the results, albeit highly suggestive, lack physiologic significance. This view stems from the fact that the concentrations of zinc used in these studies may not be encountered under the normal circumstances of life. This caveat is due to the lack of a zinc-specific probe with which to measure the concentrations of Zn2+ that may be released from neurons or act upon them. However, a …

Naïve Hosts Of Avian Brood Parasites Accept Foreign Eggs, Whereas Older Hosts Fine-Tune Foreign Egg Discrimination During Laying, Csaba Moskát, Miklós Bán, Mark E. Hauber

Publications and Research

Background: Many potential hosts of social parasites recognize and reject foreign intruders, and reduce or altogether escape the negative impacts of parasitism. The ontogenetic basis of whether and how avian hosts recognize their own and the brood parasitic eggs remains unclear. By repeatedly parasitizing the same hosts with a consistent parasitic egg type, and contrasting the responses of naïve and older breeders, we studied ontogenetic plasticity in the rejection of foreign eggs by the great reed warbler (Acrocephalus arundinaceus), a host species of the common cuckoo (Cuculus canorus).

Results: In response to experimental parasitism before the …

Rendering The Unthinkable: (Un)Knowable Animality, Compulsory Recovery, And Heterosexualized Trauma In The Hunger Games, Jennifer Polish

Dissertations, Theses, and Capstone Projects

Dystopian fiction is expected to reflect deeply on the interactions between identities, bodies, and state control. Suzanne Collins's The Hunger Games Trilogy is no exception. The disturbing trilogy situated animality, disability, and trauma (both of non-humans and of humans) as being firmly controlled by the power of the state (the Capitol). Through its portrayal of hunting and genetic manipulation, the trilogy constructed a state-created animality which refused definitive labeling and insisted upon facing animal subjectivity while simultaneously disregarding the needs and desires of those considered to be non-human. Similarly, the state held sway over both the creation and elimination of …

Comparative Phylogeography, Phylogenetics, And Population Genomics Of East African Montane Small Mammals, Terrence Constant Demos

Dissertations, Theses, and Capstone Projects

The Eastern Afromontane region of Africa is characterized by striking levels of endemism and species richness which rank it as a global biodiversity hotspot for diverse plants and animals including mammals, but has been poorly sampled and little studied to date. Using mtDNA and multi-locus nDNA sequence data, genome-wide RAD-Seq SNP data, and morphological data, I identify major cryptic biogeographic patterns within and between 11 co-distributed small mammal species/species groups across the Eastern Afromontane region. I focus on two endemic montane small mammal species complexes, Hylomyscus mice and Sylvisorex shrews, co-distributed across the Albertine Rift (AR) and Kenya Highlands (KH) …

Host Responses To Interspecific Brood Parasitism: A By-Product Of Adaptations To Conspecific Parasitism?, Peter Samas, Mark E. Hauber, Phillip Cassey, Tomáš Grim

Publications and Research

Background: Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host’s ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with …

Multilocus Coalescent Analyses Reveal The Demographic History Of Mouse Lemur Sister Species., Christopher Blair, Kellie L. Heckman, Amy L. Russell, Anne D. Yoder

Publications and Research

Debate continues as to whether allopatric speciation or peripatric speciation through a founder effect is the predominant force driving evolution in vertebrates. The mouse lemurs of Madagascar are a system in which evolution has generated a large number of species over a relatively recent time frame. Here, we examine speciation patterns in a pair of sister species of mouse lemur, Microcebus murinus and M. griseorufus. These two species have ranges that are disparately proportioned in size, with M. murinus showing a much more extensive range that marginally overlaps that of M. griseorufus. Given that these two species are …

Nest Destruction Elicits Indiscriminate Con- Versus Heterospecific Brood Parasitism In A Captive Bird, Rachel C. Shaw, William E. Feeney, Mark E. Hauber

Publications and Research

Following nest destruction, the laying of physiologically committed eggs (eggs that are ovulated, yolked, and making their way through the oviduct) in the nests of other birds is considered a viable pathway for the evolution of obligate interspecific brood parasitism. While intraspecific brood parasitism in response to nest predation has been experimentally demonstrated, this pathway has yet to be evaluated in an interspecific context. We studied patterns of egg laying following experimental nest destruction in captive zebra finches, Taeniopygia guttata, a frequent intraspecific brood parasite. We found that zebra finches laid physiologically committed eggs indiscriminately between nests containing conspecific eggs …

Agalychnis Dacnicolor—Predation., Víctor H. Jiménez-Arcos, Eric Centenero-Alcala, Leopoldo D. Vázquez Reyes, Christopher Blair, Samuel A. Santa Cruz-Padilla

Publications and Research

No abstract provided.