The dynamics, interactions and phenotypes associated with the three members of the 14-3-3 family in Drosophila melanogaster /
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2005]
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| Online Access: | Link to OAK Trust copy |
| Abstract: | It has been proposed that the various 14-3-3 isotypes and isoforms present in all eukaryotes are largely functionally equivalent. However, this is not consistent with the conservation of multiple isoforms and isotypes, especially in vertebrates with seven 14-3-3 encoding genes and nine isotypes. The hypothesis tested in this thesis is that both isoform-specific and overlapping functions are likely mediated through tissue specific expression, colocalization and dimerization of 14-3-3 proteins occur in vivo. Drosophila melanogaster was selected because it offers a simple, but representative system to study these proteins functionally. This thesis focuses primarily on D14-3-3[epsilon], although the expression pattern and phenotypes associated with all three Drosophila 14-3-3s were determined. I first determined the expression pattern of the three different 14-3-3 isotypes (leoI, leoII and D14-3-3[epsilon]) and described developmental phenotypes associated with mutations in 14-3-3 isotypes in Drosophila. I found that there is partial redundancy with respect to lethality. Both LEO and D14-3-3[epsilon] appear required for normal germ-line and somatic gonadal development. However, they do not appear to be functionally equivalent with respect to this phenotype since LEO is unable to compensate for the loss of D14-3-3[epsilon]. I also determined that D14-3-3[epsilon] mutants have unique phenotypes including deficits in adult cross-vein formation and rapid habituation to olfactory and footshock stimuli. To further understand the unique role that D14-3-3[epsilon] plays in the adult CNS, I mapped the areas in the brain involved in olfactory and footshock habituation. I found that although the mushroom bodies (MBs) are necessary to inhibit premature habituation such as that exhibited by D14-3-3[epsilon] mutants, D14-3-3[epsilon] expression specifically in the MBs is not sufficient to rescue premature habituation. Although the loss of either LEO or D14-3-3[epsilon] appears to cause a deficit in olfactory associative learning, premature habituation is the cause of the deficit seen in D14-3-3[epsilon] mutants. As leo mutants do not exhibit a premature habituation phenotype, it appears that within the MBs LEO and D14-3-3[epsilon] are not functionally equivalent. Therefore, the data supports the hypothesis that 14-3-3s have functional specificity and redundancy likely to represent use of homo and heterodimers in different processes within the tissues of an organism. |
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| Item Description: | "Major Subject: Genetics" Title from author supplied metadata (automated record created on Nov. , 09:45:50.) Vita. Abstract. Electronic resource. |
| Format: | Mode of access: World Wide Web. System requirements: World Wide Web access and Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |