An Ao-kay thesis: A cytological approach to the molecular role of Abnormal Oocyte (ao) Restricted; Files Only

Abstract

Abnormal oocyte (ao, formerly: abo) is a Drosophila maternal effect gene first characterized in 1970. Loss-of-function mutations cause lethality during early embryogenesis but can be rescued with excess heterochromatin. Later characterization suggested that Ao negatively regulates histone gene expression, providing a satisfying mechanistic explanation for earlier observations. After this discovery, ao received little attention. We recently developed new ao genetic tools and discovered Ao is likely not a histone regulator in ovaries, despite localizing to the histone gene cluster. In order to determine if Ao influences histones in other tissues, we leveraged our endogenously tagged ao transgenes. Here, we show Ao does not localize to the histone gene cluster in larval polytene chromosomes, as previously shown, even in an overexpression environment. However, we observe Ao localization to the histone genes in blastula-stage and later embryos, indicating tissue specificity. Yet, even in embryos, Ao does not affect histone transcript levels. Further entangling our understanding of Ao, is that our recent work illustrated Ao levels were sensitive to histone gene stoichiometry. Thus, we also assess Ao localization in a reduced and histone gene environment. Our work indicates Ao localization without regulation and reopens the fifty-year-old mystery into the role of Ao with potential insights into its molecular mechanism.

Table of Contents

Abstract......................................................................................................................... 1

 

Introduction.................................................................................................................. 1

 

Results.......................................................................................................................... 3

 

Discussion.................................................................................................................. 11

 

Materials and Methods.............................................................................................. 16

 

Author Contributions................................................................................................. 23

 

References.................................................................................................................. 24

 

Supplemental Figures............................................................................................... 29

 

Appendix..................................................................................................................... 34

About this Honors Thesis

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School	Emory College
Department	Biology
Degree	B.S.
Submission	Honors Thesis
Language	English
Research Field	Biology, Evolution and Development Biology, Molecular Biology, Genetics
Keyword	Drosophila Histone Cell cycle Microscopy Embryogenesis Immunofluorescence Gene Regulation
Committee Chair / Thesis Advisor	Rieder, Leila, Emory University
Committee Members	Cafferty, Patrick , Emory University Weinschenk, Matthew , Emory University

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