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Regulation by male-specific fruitless of neural circuitry used during courtship and copulation behavior in Drosophila melanogasterLatham, Kristin Lynn 09 June 2005 (has links)
Courtship and copulation behaviors in Drosophila melanogaster males are
regulated by sex-specific products from the gene fruitless (fru). Male-specific FRU
proteins (FRU[superscript M]) are putative transcription factors of the BTB-ZnF family that likely
act by controlling development and maintenance of the neural circuitry used during
male sexual behavior. However, which neuronal characteristics are regulated by
FRU[superscript M] is mostly unknown and how FRU[superscript M] neurons are grouped into circuits and the
role that specific neuronal circuits play in sexual behavior has not been elucidated. I
have identified a subset of FRU[superscript M] neurons that co-express the transcription factor,
Engrailed (En). After fru[superscript M]-RNAi-induced targeted removal of FRU[superscript M] proteins from
FRU[superscript M]/En neurons, males were impaired in their ability to initiate or maintain
copulation. Further, I examined two characteristics, the initial projections and
neurotransmitters used by FRU[superscript M]/En neurons. Males and females showed a difference
in the neurochemistry of FRU[superscript M]/En neurons in the thoracic ganglia; this
neurochemistry is disrupted in fru mutant males.
For one cohort of serotonergic neurons in the abdominal ganglion that were
previously shown to be dependent on FRU[superscript M] for expression of serotonin, I determined
that FRU[superscript M] works in conjunction with other sex-specific genes, TAKEOUT (TO) and
DOUBLESEX (DSX), to induce of serotonin expression in males; in females
serotonin expression is repressed by DSX and TO.
Finally, I performed a genetic screen for genes that interact with, or are
downstream targets of, fru, dsx, or dissatisfaction (dsf). I assessed fertility, copulation
success, and abdominal muscle development of EMS-mutagenized flies, resulting in
one fly line in which homozygous mutant animals had a novel muscle phenotype. By
genetic tests, the mutation was found to be allelic to string, which encodes a Cdc25-
like phosphatase.
Taken together, my research demonstrates that subsets of FRU[superscript M] neurons
function in circumscribed circuits to regulate specific portions of sexual behavior, and
that FRU[superscript M], along with other sex-specific genes, controls development of these
neurons in part by determining neurochemistry. Further, FRU[superscript M] likely directs multiple
downstream targets, in different subsets of neurons in which it is expressed, which
collectively provide correct development of neural circuits underlying courtship and
copulation behavior. / Graduation date: 2006
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The genetic dissection of the fruitless gene's functions during embryogenesis in Drosophila melanogasterSong, Ho-Juhn 16 August 2001 (has links)
The fruitless (fru) gene in Drosophila melanogaster is a multifunctional
gene having sex-specific functions in the regulation of male sexual behavior and
sex-nonspecific functions affecting adult viability and external morphology. While
much attention has focused on fru's sex-specific roles, little is known about its sex-nonspecific
functions. The embryonic central nervous system (CNS) is a prime
model system in which to study the genetic control of axonal outgrowth and proper
CNS formation. I have examined fru's sex-nonspecific role in embryonic neural
development. fru transcripts and FRU proteins from sex-nonspecific promoters are
expressed beginning at the earliest stages of neurogenesis and subsequently in both
neurons and glia. In embryos that lack most or all fru function, Fasciclin II- and
BP102-positive axons appeared to defasciculate from their normal pathway and
fasciculate along aberrant neuronal pathways, suggesting that one of fru's sex-nonspecific
roles is to regulate axonal differentiation. I next examined whether the
loss of fru function in FRU-expressing neuronal precursors causes neuronal fate
change. Analysis of fru mutant embryos revealed a lack of Even-skipped (Eve)
staining in Eve-expressing neurons, ectopic Eve staining in non-Eve-expressing
neurons and mispositioned dorsal Eve-expressing neurons, which suggests that fru
functions to maintain neuronal identity rather than to specify neuronal fate. In fru
mutants these defects in axonal projections and in Eve staining were rescued by the
expression of specific fru transgenes.
To better understand fru's function in the formation of the embryonic CNS,
I dissected out fru's function in neuron and glia through a genetic interaction study.
fru genetically interacts in neurons with longitudinal lacking to make proper axonal
projections. In addition, fru might be in the same genetic pathway as roundabout
(robo), a repulsive guidance receptor, and commissureless, a downregulator of
Robo, to ensure proper axonal pathfinding. Surprisingly, fru interacts with
tramtrack and glial cells missing to repress neuronal differentiation in the lateral
glia and with single-minded for the development of midline glia. Taken together,
fru function is required for proper axonal pathfinding in neurons and for proper
development of lateral and midline glia. / Graduation date: 2002
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Fate's grim intervention : determining sibling relationships and mechanisms of cell fate specification in the NB7-3 lineage of the Drosophila embryonic CNS /Karcavich, Rachel Elaine. January 2001 (has links)
Thesis (Ph. D.)--University of Oregon, 2001. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 99-105). Also available for download via the World Wide Web; free to University of Oregon users.
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Developing an eggshell marker based on a dominant female sterile mutation for the identification of complete follicle cell clones in Drosophila melanogasterEleiche, Aliaa Abdel-Salam. January 2006 (has links)
Patterning of the body axes of the Drosophila embryo depends on maternally expressed genes, some of which function in the follicular epithelium of the developing egg chamber. Many such genes were identified in genetic screens for homozygous mutant females that produce abnormal embryos. However, mutations in zygotically required maternal effect genes are homozygous lethal, and therefore viable females cannot be recovered using this screening approach. This limitation can be overcome by generating homozygous mutant follicle cell clones in heterozygous females using a system that induces site-specific mitotic recombination events. However, to date, eggs produced from egg chambers with complete follicle cell clones cannot be directly identified. We have developed an eggshell marker for follicle cell clones using a dominant negative (DN) allele of the gene defective chorion (dec). Females with a single copy of this allele, decDN, lay collapsed eggs and are therefore sterile. Site-specific mitotic recombination events induced in females heterozygous for decDN and a mutation on the homologous chromosome arm result in homozygous mutant follicle cells that have lost decDN. Therefore, egg chambers with the entire follicular epithelium homozygous mutant generate intact eggs that can be unambiguously identified amongst otherwise collapsed eggs.
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The evolution of sex-related traits and speciation in Drosophila /Civetta, Alberto. January 1998 (has links)
Thesis ( Ph.D.) -- McMaster University, 1998. / Includes bibliographical references (leaves 136-139). Also available via World Wide Web.
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Determining roles of the SUN domain proteins klaroid and Dspag4 in Drosophila developmentKracklauer, Martin Paul, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
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Steroid hormone receptor regulation of neuronal pruning and outgrowth in the Drosophila central nervous system /Brown, Heather L. D. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 121-139).
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<>.Rahman, Ishita. January 2008 (has links) (PDF)
Undergraduate honors paper--Mount Holyoke College, 2008. Dept of Biological Sciences. / Non-Latin script record. Includes bibliographical references (leaves 85-92).
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Genetic dissection of the transcriptional hypoxia response and genomic regional capture for massively parallel sequencing /Turnbull, Douglas William, January 2008 (has links)
Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 90-99). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
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Roles of the Rho1 small GTPase during development in Drosophila melanogaster /Magie, Craig Robert. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 140-161).
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