Expression of the Ets family in the lens
| Author(s) | O'Leary, Christine Marie | |
| Date Accessioned | 2020-07-24T11:49:51Z | |
| Date Available | 2020-07-24T11:49:51Z | |
| Publication Date | 2005 | |
| Abstract | The intricate process of lens fiber cell differentiation is regulated by multiple signaling pathways including the Fibroblast Growth Factor (FGF) cascade. This pathway induces the activation of cytoplasmic factors Ras-Raf which in turn can activate Erk. The active form of Erk causes phosphorylation of inactive transcription factors rendering them active. This final step results in a permanent alteration of gene expression. ☐ Currently, all the identities of the transcription factors involved in the process of lens fiber cell differentiation are not yet known; however, a transcription factor family known to be regulated by FGF is the Ets family. The Ets family consists of at least 30 members that each contain a characteristic winged helix-turn-helix DNA binding domain. ☐ A specific member of this family, Ets2, was previously shown by the Duncan Laboratory to be expressed at high levels in the lens transition zone through immunohistochemistry. The presence of Ets2 in this crucial differentiation region along with the Ets family’s known ability to interact with the FGF pathway suggests that it may be playing a role in the modulation of gene transcription. ☐ In order to better understand the potential roles of this family, the presence of each family member was first explored at the mRNA level. An Ets2 dominant negative transgenic mouse model was also created to further explore the role that the Ets family may play in lens fiber cell differentiation in vivo. ☐ The expression pattern of the known Ets family members was explored in the murine lens during the adult and 16.5dpc stages using quantitative RT-PCR. The lens was divided into three tissue groups, epithelia, lens fiber cell, and whole lens for this study. In all, eight family members displayed significant expression levels. ☐ When contrasting the RNA expression results from adult lens epithelia to lens fiber cell samples, Ets2, as well as other family members, (ER81, ERM, TEL, ELK4) were expressed at high levels in the epithelia, while only ERM and TEL were expressed at high levels in the lens fiber cells. In the comparison, between the whole adult lens and the whole 16.5dpc lens, only ERM and TEL were highly expressed in the adult whole lens, while Ets1, Ets2, ERM, ER81, all three ELKs, and TEL were highly expressed in the embryonic lens. ☐ The dominant negative transgenic mouse model was created from a fusion between the Ets2 DNA binding domain-LacZ reporter vector and the A-Crystallin promoter. Pronuclear injections were performed and resulting founders were screened for the designed transgene. Of the nine positive resulting founders only one transmitted the transgene to its offspring. While the transgene appears to be present at the DNA level, no ocular phenotypes resulted. ☐ The presence of Ets family members at high levels in the RNA samples assayed suggests that through possible interactions with the FGF pathway, they may play an important role in the process of lens fiber cell differentiation. | en_US |
| Advisor | Duncan, Melinda K. | |
| Degree | M.S. | |
| Department | University of Delaware, Department of Biological Sciences | |
| Unique Identifier | 75643867 | |
| URL | http://udspace.udel.edu/handle/19716/27343 | |
| Publisher | University of Delaware | en_US |
| URI | https://search.proquest.com/docview/304992629?accountid=10457 | |
| dc.subject.lcsh | Crystalline lens | |
| dc.subject.lcsh | Gene expression | |
| Title | Expression of the Ets family in the lens | en_US |
| Type | Thesis | en_US |