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Full-Text Articles in Cell Biology

The Specification Of Hemogenic Endothelium During Embryogenesis And Beyond, Amanda Danielle Yzaguirre Jan 2017

The Specification Of Hemogenic Endothelium During Embryogenesis And Beyond, Amanda Danielle Yzaguirre

Publicly Accessible Penn Dissertations

The primary goal of regenerative medicine is the in vitro derivation of cells that are functional and safe for transplantation into patients. Although progress has been made towards this goal there are no clinical applications that utilize cells derived in vitro from pluripotent stem cells or reprogrammed primary cells. The foremost reason for this is an incomplete understanding of the development processes that regulate cell identity. In order to gain a better understanding of the specification of hematopoietic stem cells (HSC), I studied their de novo generation during embryogenesis.

Using confocal microscopy, I mapped out hematopoiesis during midgestation and discovered ...


The Role Of The Dosage Compensation Complex As A Pathway For Spiroplasma To Induce Male Lethality In Drosophila Melanogaster, Becky Cheng Jan 2017

The Role Of The Dosage Compensation Complex As A Pathway For Spiroplasma To Induce Male Lethality In Drosophila Melanogaster, Becky Cheng

CMC Senior Theses

Drosophila melanogaster and many other insects harbor intracellular bacterial symbionts that are transmitted vertically from infected host mothers to their offspring. Many of these bacteria alter host reproductive developmental processes in order to increase their transmission success. For example, Spiroplasma, a spirochete that naturally infects D. melanogaster, selectively kills males during mid-embryogenesis while sparing females. Previous studies suggested that Spiroplasma interacts genetically with the male-specific dosage compensation pathway, which causes ~2-fold up-regulation of most genes located on the male’s single X chromosome so that their expression matches the levels found in females who have two Xs. To further test ...


Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve Aug 2015

Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of regenerative medicine seeks to create replacement tissues and organs, both to repair deficiencies in biological function and to treat structural damage caused by injury. Scaffoldings mimicking extracellular matrix (ECM), the structure to which cells attach to form tissues, have been developed from synthetic polymers and also been prepared by decellularizing adult tissue. However, the structure of ECM undergoes significant remodeling during natural tissue repair, suggesting that ECM-replacement constructs that mirror developing tissues may promote better regeneration than those modeled on adult tissues. This work investigated the effectiveness of a method of viewing the extracellular matrix of developing ...


A New Role For The Endoplasmic Reticulum At Endosome Contact Sites, Ashley Ann Rowland Jan 2015

A New Role For The Endoplasmic Reticulum At Endosome Contact Sites, Ashley Ann Rowland

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

The Endoplasmic Reticulum (ER) forms a dynamic network that spans throughout the cell. In addition to the well characterized roles in lipid synthesis, protein folding, and calcium handling, the ER coordinates important functions at stable membrane contact sites formed with other organelles. Recent work from the lab demonstrated that ER tubules circumscribe mitochondrial constrictions and define the position of mitochondrial fission. We predicted that mechanisms of membrane fission are conserved between various organelles. Here we hypothesized and tested whether ER contacts define the timing and the position of endosome fission. Endocytic cargo and Rab GTPases are segregated to distinct domains ...