Life Sciences Commons^™

Regulators Of Ins-6, A Major Node Of The Insulin-Like Peptide Network For Developmental Plasticity, Lisa Li

Wayne State University Theses

In C. elegans, an insulin-like peptide (ILP) network coordinates various physiological

processes, including developmental plasticity, to enhance survival under different environments. During stressful conditions, such as high temperatures, low food and high population density, first-stage larval worms enter an alternative developmental arrest program called dauer. When ideal environmental conditions are restored, worms exit from the dauer stage to go through reproductive adulthood. Different subsets of ILPs regulate the entry into versus the exit from the dauer state. For example, the ILP ins-6 plays a minor role in inhibiting dauer entry from the ASI sensory neurons, but a more primary role …

Developmental Evolution Of The Visual System In The Cave-Adapted Small Carrion Beetle Ptomaphagus Hirtus, Jasmina Kulacic

Wayne State University Theses

Extensive research has been done to date on Drosophila and Tribolium eye development; however, not much is known about the molecular basis of development of extremely reduced and modified eyes in cave insects. Ptomaphagus hirtus represents an emerging model system for studying the changes at the molecular level that occurred during the evolutionary adaptation of the eye to the cave environment. Therefore, I have started exploring the morphology and organization of the reduced P. hirtus eyelet, using immunohistochemistry, laser scanning microscopy, and ultrastructural imaging approaches. My findings demonstrate that the adult eyelet lacks ommatidial subdivision and has a thick, clear …

The Xenopus Lefty (Xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion, Adrian Amelio Vasquez

Wayne State University Theses

In vertebrates, the TGF #914; superfamily of secreted peptides are stringently regulated since they are responsible for multiple cell processes and behaviors that give rise to the proper patterning of embryonic tissues. Examples of members of the TGF #914; superfamily are Nodal and Lefty. Dysregulation of these proteins can lead to many diseases and developmental syndromes in humans.

Lefty functions by antagonizing Nodal an essential organizer signal that patterns dorsal mesoderm and the embryonic axes. Loss of Lefty expression results in excess Nodal signaling which has been shown to cause several perturbations including metastatic cancer. Although studies have clearly shown …

Pax6 Is Required For The Development Of The Lateral Procephalon In Tribolium, Qing Luan

Wayne State University Theses

In Tribolium, combinatorial knockdown of the Pax6 orthologs eyeless (ey) and twin of eyeless (toy) affects the peripheral visual system but also other areas of the dorsal larval head capsule. To elucidate the role of Pax6 genes during Tribolium embryonic head development in detail, we performed an extensive analysis of cuticle

elements, brain anatomy, embryonic head morphogenesis and developmental marker gene expression. Our results reveal that Pax6 is required for the development of a large contiguous area of the lateral anterior head, morphologically addressed as the embryonic head lobes, which encompass the neuroectodermal precursor tissues of the visual system, parts …