Life Sciences Commons^™

An Analysis Of The Involvement Of Toll Receptors In Cell Movements During The Elongation Of Tribolium Castaneum, Kathryn Russell

Senior Theses and Projects

Elongation of the anterior/posterior body axis is a critical part of embryonic development. Cell movements are known to play a significant role in embryo elongation in the red flour beetle Tribolium castaneum. In the arthropod model organism, Drosophila, Toll receptors have a demonstrated role in the elongation of the embryo by driving convergent extension, in which rows of cells intercalate with one another in one direction to extend tissue in the other. In Drosophila, Toll receptors are a link between anterior-posterior patterning genes expressed in discrete stripes and effector molecules causing cell movements. This cell movement is caused …

The Role And Regulation Of The Caudal Gene In Tribolium Castaneum Segmentation, Suzanne Nicole Carpe Elias

Senior Theses and Projects

The embryo of the red flour beetle Tribolium castaneum develops sequentially by adding segments in an anterior-to-posterior progression using a “clock”-like mechanism similar to that of vertebrates. Previous studies indicate that the oscillations of this segmentation clock are driven by a gradient of the transcription factor caudal (cad), which activates and regulates the clock. Knocking down the cad gene using parental or early embryonic RNAi leads to animals with only head segments. We hypothesized that progressively later embryonic knockdowns would produce animals with progressively more segments if the function of cad does not change during segmentation. To examine …

The Effect Of Hypoxia On Brain Cell Proliferation In Weakly Electric Fish, Petrocephalus Degeni, Kaitlin Klovdahl

Senior Theses and Projects

Oxygen levels tend to remain at a steady state concentration in the Earth’s atmosphere, yet in some bodies of water, they can fluctuate and decrease drastically. Many organisms that inhabit the swamps, lakes, streams, and parts of the ocean where this occurs have evolved adaptations to manage this environmental uncertainty and continue normal oxygen consumption. The Lwamunda swamp in Uganda is chronically hypoxic, yet it is home to many species, including the electric fish Petrocephalus degeni. P. degeni are unusual by nature of their immense brain, and the Lwamunda swamp appears ill-suited for maintaining this large, metabolically active organ. To …

Investigating Notch Signaling And Sequential Segmentation In The Fairy Shrimp, Thamnocephalus Platyurus, Sara Izzat Khalil

Senior Theses and Projects

Segmentation is a key feature of arthropod diversity and evolution. In the standard model for arthropod development, Drosophila melanogaster, segments develop simultaneously by a progressive subdivision of the embryo. By contrast, most arthropods add segments sequentially from a posterior region called the growth zone and in a manner similar to vertebrates.

Recent work, mainly focused on insects, suggests that Notch signaling might play a role in arthropods that segment sequentially. These studies document a potential regulatory similarity between sequentially segmenting arthropods and vertebrates. In vertebrates, somite formation involves a molecular oscillator that functions as a pacemaker, driving periodic expression …