<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-19T06:11:10Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/40957" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/40957</identifier><datestamp>2022-01-13T07:54:15Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131022</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">H. Robert Horvitz.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Gustafson, Megan Alyse</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Dept. of Biology.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Biology</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2008-03-27T18:28:44Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2008-03-27T18:28:44Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/40957</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">213078324</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2007.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">Wild-type animals that have been acutely food deprived slow their locomotory rate upon encountering bacteria more than do well-fed animals. This behavior, called the enhanced slowing response, is partly serotonin (5-HT) dependent. Animals mutant for the 5-HT reuptake transporter gene mod-5 slow even more than wild-type animals because endogenous 5-HT activity is potentiated. This behavior, called the hyperenhanced slowing response, can be suppressed by mutations in genes that encode proteins important for 5-HT signaling, like the 5-HT receptor encoded by mod-1 and the Ga subunit of a G protein encoded by goa-1. This ability to suppress indicates that these genes likely act downstream of or in parallel to one or more 5-HT synapse(s) that mediate(s) the enhanced slowing response. To find genes that play a role in 5-HT signaling, we screened for suppressors of the 5-HT hypersensitivity of mod-5. We found at least seven alleles of goa-i and at least two alleles of mod-1. This shows that our screen is able to target genes that play a role in endogenous 5-HT signaling. We identified two alleles of the FMRFamide-encoding gene fp-1, which was known to mediate paralysis in exogenous 5-HT. We showed that loss-of-function mutations in flp-1 confer an enhanced slowing response defect. We also identified an allele of abts-1, which encodes a bicarbonate transporter, and showed that it has defects in cholinergic signaling. We identified three mutants that show linkage to LG I, four to II, three to V and one to X, most of which display defects consistent with a role in 5-HT signaling.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">(cont.) We used a candidate gene approach to find that deletions in ser-4, which encodes a metabotropic 5-HT receptor, confer 5-HT resistance. ser-4 acts redundantly with the ionotropic 5-HT receptor mod-1 to suppress the hyperenhanced slowing response of mod-5. Our genetic analysis suggests that ser-4 acts in a pathway with goa-1, in parallel to mod-1. We found that the enhanced slowing response defect of flp-1 is primarily due to its defect in transmitting a 5-HT signal and that flp-1 likely acts downstream of ser-4 and mod-1.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Megan Alyse Gustafson.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">Ph.D.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">121, [6] leaves</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by 
copyright. They may be viewed from this source for any purpose, but 
reproduction or distribution in any format is prohibited without written 
permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri" lang="en_US">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Biology.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Serotonin signaling in C. elegans</dim:field>
   <dim:field mdschema="dc" element="title" qualifier="alternative" lang="en_US">Serotonin signaling in Cerevisiae elegans</dim:field>
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   	&lt;Title>Serotonin signaling in C. elegans&lt;/Title>
   	&lt;Subtitle>Serotonin signaling in Cerevisiae elegans&lt;/Subtitle>
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   	&lt;PublicationDate>2007&lt;/PublicationDate>
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        	&lt;DisplayName>Gustafson, Megan Alyse&lt;/DisplayName>
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    &lt;Keyword>Biology.&lt;/Keyword>
   	&lt;Abstract>Wild-type animals that have been acutely food deprived slow their locomotory rate upon encountering bacteria more than do well-fed animals. This behavior, called the enhanced slowing response, is partly serotonin (5-HT) dependent. Animals mutant for the 5-HT reuptake transporter gene mod-5 slow even more than wild-type animals because endogenous 5-HT activity is potentiated. This behavior, called the hyperenhanced slowing response, can be suppressed by mutations in genes that encode proteins important for 5-HT signaling, like the 5-HT receptor encoded by mod-1 and the Ga subunit of a G protein encoded by goa-1. This ability to suppress indicates that these genes likely act downstream of or in parallel to one or more 5-HT synapse(s) that mediate(s) the enhanced slowing response. To find genes that play a role in 5-HT signaling, we screened for suppressors of the 5-HT hypersensitivity of mod-5. We found at least seven alleles of goa-i and at least two alleles of mod-1. This shows that our screen is able to target genes that play a role in endogenous 5-HT signaling. We identified two alleles of the FMRFamide-encoding gene fp-1, which was known to mediate paralysis in exogenous 5-HT. We showed that loss-of-function mutations in flp-1 confer an enhanced slowing response defect. We also identified an allele of abts-1, which encodes a bicarbonate transporter, and showed that it has defects in cholinergic signaling. We identified three mutants that show linkage to LG I, four to II, three to V and one to X, most of which display defects consistent with a role in 5-HT signaling.&lt;/Abstract>
   	&lt;Abstract>(cont.) We used a candidate gene approach to find that deletions in ser-4, which encodes a metabotropic 5-HT receptor, confer 5-HT resistance. ser-4 acts redundantly with the ionotropic 5-HT receptor mod-1 to suppress the hyperenhanced slowing response of mod-5. Our genetic analysis suggests that ser-4 acts in a pathway with goa-1, in parallel to mod-1. We found that the enhanced slowing response defect of flp-1 is primarily due to its defect in transmitting a 5-HT signal and that flp-1 likely acts downstream of ser-4 and mod-1.&lt;/Abstract>
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