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   <ui>1687-4153-2007-70561</ui>
   <ji>1687-4153</ji>
   <fm>
      <dochead>Research Article</dochead>
      <bibl>
         <title>
            <p>Clustering Time-Series Gene Expression Data Using Smoothing Spline Derivatives</p>
         </title>
         <aug>
            <au ca="yes" id="A1"><snm>D&#233;jean</snm><fnm>S</fnm><insr iid="I1"/><email>sebastien.dejean@math.ups-tlse.fr</email></au>
            <au id="A2"><snm>Martin</snm><fnm>PGP</fnm><insr iid="I2"/><email>pascal.martin@toulouse.inra.fr</email></au>
            <au id="A3"><snm>Baccini</snm><fnm>A</fnm><insr iid="I1"/><email>alain.baccini@math.ups-tlse.fr</email></au>
            <au id="A4"><snm>Besse</snm><fnm>P</fnm><insr iid="I1"/><email>philippe.besse@math.ups-tlse.fr</email></au>
         </aug>
         <insg>
            <ins id="I1"><p>Laboratoire de Statistique et Probabilit&#233;s, UMR 5583, Universit&#233; Paul Sabatier, Toulouse Cedex 9 31062, France</p></ins>
            <ins id="I2"><p>Laboratoire de Pharmacologie et Toxicologie, UR 66, Institut National de la Recherche Agronomique (INRA), 180 Chemin de Tournefeuille, BP 3, Toulouse Cedex 9 31931, France</p></ins>
         </insg>
         <source>EURASIP Journal on Bioinformatics and Systems Biology</source>
         <issn>1687-4153</issn>
         <pubdate>2007</pubdate>
         <volume>2007</volume>
         <issue>1</issue>
         <fpage>70561</fpage>
         <url>http://bsb.eurasipjournals.com/content/2007/1/70561</url>
         <xrefbib><pubid idtype="doi">10.1155/2007/70561</pubid></xrefbib>
      </bibl>
      <history><rec><date><day>14</day><month>12</month><year>2006</year></date></rec><revrec><date><day>6</day><month>3</month><year>2007</year></date></revrec><acc><date><day>16</day><month>5</month><year>2007</year></date></acc><pub><date><day>18</day><month>6</month><year>2007</year></date></pub></history>
      <cpyrt><year>2007</year><collab>S. D&#233;jean et al.</collab><note>This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</note></cpyrt>
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            <p>Microarray data acquired during time-course experiments allow the temporal variations in gene expression to be monitored. An original postprandial fasting experiment was conducted in the mouse and the expression of 200 genes was monitored with a dedicated macroarray at 11 time points between 0 and 72 hours of fasting. The aim of this study was to provide a relevant clustering of gene expression temporal profiles. This was achieved by focusing on the shapes of the curves rather than on the absolute level of expression. Actually, we combined spline smoothing and first derivative computation with hierarchical and partitioning clustering. A heuristic approach was proposed to tune the spline smoothing parameter using both statistical and biological considerations. Clusters are illustrated a posteriori through principal component analysis and heatmap visualization. Most results were found to be in agreement with the literature on the effects of fasting on the mouse liver and provide promising directions for future biological investigations.</p>
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      <refgrp><bibl id="B1"><title><p>Statistical tests for identifying differentially expressed genes in time-course microarray experiments</p></title><aug><au><snm>Park</snm><fnm>T</fnm></au><au><snm>Yi</snm><fnm>S-G</fnm></au><au><snm>Lee</snm><fnm>S</fnm></au><etal/></aug><source>Bioinformatics</source><pubdate>2003</pubdate><volume>19</volume><issue>6</issue><fpage>694</fpage><lpage>703</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1093/bioinformatics/btg068</pubid><pubid idtype="pmpid" link="fulltext">12691981</pubid></pubidlist></xrefbib></bibl><bibl id="B2"><title><p>Gene selection and clustering for time-course and dose-response microarray experiments using order-restricted inference</p></title><aug><au><snm>Peddada</snm><fnm>SD</fnm></au><au><snm>Lobenhofer</snm><fnm>EK</fnm></au><au><snm>Li</snm><fnm>L</fnm></au><au><snm>Afshari</snm><fnm>CA</fnm></au><au><snm>Weinberg</snm><fnm>CR</fnm></au><au><snm>Umbach</snm><fnm>DM</fnm></au></aug><source>Bioinformatics</source><pubdate>2003</pubdate><volume>19</volume><issue>7</issue><fpage>834</fpage><lpage>841</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1093/bioinformatics/btg093</pubid><pubid idtype="pmpid" link="fulltext">12724293</pubid></pubidlist></xrefbib></bibl><bibl id="B3"><title><p>Significance analysis of time course microarray experiments</p></title><aug><au><snm>Storey</snm><fnm>JD</fnm></au><au><snm>Xiao</snm><fnm>W</fnm></au><au><snm>Leek</snm><fnm>JT</fnm></au><au><snm>Tompkins</snm><fnm>RG</fnm></au><au><snm>Davis</snm><fnm>RW</fnm></au></aug><source>Proceedings of the National Academy of Sciences of the United States of America</source><pubdate>2005</pubdate><volume>102</volume><issue>36</issue><fpage>12837</fpage><lpage>12842</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1073/pnas.0504609102</pubid><pubid idtype="pmcid">1201697</pubid><pubid idtype="pmpid" link="fulltext">16141318</pubid></pubidlist></xrefbib></bibl><bibl id="B4"><title><p>A multivariate empirical Bayes statistic for replicated microarray time course data</p></title><aug><au><snm>Tai</snm><fnm>YC</fnm></au><au><snm>Speed</snm><fnm>TP</fnm></au></aug><source>The Annals of Statistics</source><pubdate>2006</pubdate><volume>34</volume><issue>5</issue><fpage>2387</fpage><lpage>2412</lpage><xrefbib><pubid idtype="doi">10.1214/009053606000000759</pubid></xrefbib></bibl><bibl id="B5"><title><p>Cluster analysis of gene expression dynamics</p></title><aug><au><snm>Ramoni</snm><fnm>MF</fnm></au><au><snm>Sebastiani</snm><fnm>P</fnm></au><au><snm>Kohane</snm><fnm>IS</fnm></au></aug><source>Proceedings of the National Academy of Sciences of the United States of America</source><pubdate>2002</pubdate><volume>99</volume><issue>14</issue><fpage>9121</fpage><lpage>9126</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1073/pnas.132656399</pubid><pubid idtype="pmcid">123104</pubid><pubid idtype="pmpid" link="fulltext">12082179</pubid></pubidlist></xrefbib></bibl><bibl id="B6"><title><p>Clustering short time series gene expression data</p></title><aug><au><snm>Ernst</snm><fnm>J</fnm></au><au><snm>Nau</snm><fnm>GJ</fnm></au><au><snm>Bar-Joseph</snm><fnm>Z</fnm></au></aug><source>Bioinformatics</source><pubdate>2005</pubdate><volume>21</volume><issue>1</issue><fpage>i159</fpage><lpage>i168</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1093/bioinformatics/bti1022</pubid><pubid idtype="pmpid" link="fulltext">15961453</pubid></pubidlist></xrefbib></bibl><bibl id="B7"><title><p>Clustering time series gene expression data based on sum-of-exponentials fitting</p></title><aug><au><snm>Giurc&#462;neanu</snm><fnm>CD</fnm></au><au><snm>T&#462;bu&#351;</snm><fnm>I</fnm></au><au><snm>Astola</snm><fnm>J</fnm></au></aug><source>EURASIP Journal on Applied Signal Processing</source><pubdate>2005</pubdate><volume>2005</volume><issue>8</issue><fpage>1159</fpage><lpage>1173</lpage><xrefbib><pubid idtype="doi">10.1155/ASP.2005.1159</pubid></xrefbib></bibl><bibl id="B8"><title><p>Bayesian coclustering of Anopheles gene expression time series: study of immune defense response to multiple experimental challenges</p></title><aug><au><snm>Heard</snm><fnm>NA</fnm></au><au><snm>Holmes</snm><fnm>CC</fnm></au><au><snm>Stephens</snm><fnm>DA</fnm></au><au><snm>Hand</snm><fnm>DJ</fnm></au><au><snm>Dimopoulos</snm><fnm>G</fnm></au></aug><source>Proceedings of the National Academy of Sciences of the United States of America</source><pubdate>2005</pubdate><volume>102</volume><issue>47</issue><fpage>16939</fpage><lpage>16944</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1073/pnas.0408393102</pubid><pubid idtype="pmcid">1287961</pubid><pubid idtype="pmpid" link="fulltext">16287981</pubid></pubidlist></xrefbib></bibl><bibl id="B9"><title><p>maSigPro: a method to identify significantly differential expression profiles in time-course microarray experiments</p></title><aug><au><snm>Conesa</snm><fnm>A</fnm></au><au><snm>Nueda</snm><fnm>MJ</fnm></au><au><snm>Ferrer</snm><fnm>A</fnm></au><au><snm>Tal&#243;n</snm><fnm>M</fnm></au></aug><source>Bioinformatics</source><pubdate>2006</pubdate><volume>22</volume><issue>9</issue><fpage>1096</fpage><lpage>1102</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1093/bioinformatics/btl056</pubid><pubid idtype="pmpid" link="fulltext">16481333</pubid></pubidlist></xrefbib></bibl><bibl id="B10"><title><p>Designing better probes: effect of probe size, mismatch position and number on hybridization in DNA oligonucleotide microarrays</p></title><aug><au><snm>Letowski</snm><fnm>J</fnm></au><au><snm>Brousseau</snm><fnm>R</fnm></au><au><snm>Masson</snm><fnm>L</fnm></au></aug><source>Journal of Microbiological Methods</source><pubdate>2004</pubdate><volume>57</volume><issue>2</issue><fpage>269</fpage><lpage>278</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1016/j.mimet.2004.02.002</pubid><pubid idtype="pmpid" link="fulltext">15063067</pubid></pubidlist></xrefbib></bibl><bibl id="B11"><aug><au><snm>Ramsay</snm><fnm>J</fnm></au><au><snm>Silverman</snm><fnm>B</fnm></au></aug><source>Functional Data Analysis</source><publisher>Springer, New York, NY, USA</publisher><edition>2</edition><pubdate>2005</pubdate></bibl><bibl id="B12"><title><p>Continuous representations of time-series gene expression data</p></title><aug><au><snm>Bar-Joseph</snm><fnm>Z</fnm></au><au><snm>Gerber</snm><fnm>GK</fnm></au><au><snm>Gifford</snm><fnm>DK</fnm></au><au><snm>Jaakkola</snm><fnm>TS</fnm></au><au><snm>Simon</snm><fnm>I</fnm></au></aug><source>Journal of Computational Biology</source><pubdate>2003</pubdate><volume>10</volume><issue>3-4</issue><fpage>341</fpage><lpage>356</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1089/10665270360688057</pubid><pubid idtype="pmpid" link="fulltext">12935332</pubid></pubidlist></xrefbib></bibl><bibl id="B13"><title><p>Analyzing time series gene expression data</p></title><aug><au><snm>Bar-Joseph</snm><fnm>Z</fnm></au></aug><source>Bioinformatics</source><pubdate>2004</pubdate><volume>20</volume><issue>16</issue><fpage>2493</fpage><lpage>2503</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1093/bioinformatics/bth283</pubid><pubid idtype="pmpid" link="fulltext">15130923</pubid></pubidlist></xrefbib></bibl><bibl id="B14"><title><p>Transcriptional modulations by RXR agonists are only partially subordinated to PPAR<inline-formula><graphic file="1687-4153-2007-70561-i1.gif"/></inline-formula> signaling and attest additional, organ-specific, molecular cross-talks</p></title><aug><au><snm>Martin</snm><fnm>PGP</fnm></au><au><snm>Lasserre</snm><fnm>F</fnm></au><au><snm>Calleja</snm><fnm>C</fnm></au><etal/></aug><source>Gene Expression</source><pubdate>2005</pubdate><volume>12</volume><issue>3</issue><fpage>177</fpage><lpage>192</lpage><xrefbib><pubidlist><pubid idtype="doi">10.3727/000000005783992098</pubid><pubid idtype="pmpid">16128002</pubid></pubidlist></xrefbib></bibl><bibl id="B15"><title><p>Novel aspects of PPAR<inline-formula><graphic file="1687-4153-2007-70561-i2.gif"/></inline-formula>-mediated regulation of lipid and xenobiotic metabolism revealed through a nutrigenomic study</p></title><aug><au><snm>Martin</snm><fnm>PGP</fnm></au><au><snm>Guillou</snm><fnm>H</fnm></au><au><snm>Lasserre</snm><fnm>F</fnm></au><etal/></aug><source>Hepatology</source><pubdate>2007</pubdate><volume>45</volume><issue>3</issue><fpage>767</fpage><lpage>777</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1002/hep.21510</pubid><pubid idtype="pmpid" link="fulltext">17326203</pubid></pubidlist></xrefbib></bibl><bibl id="B16"><title><p>Laboratoire de Pharmacologie et Toxicologie, INRA</p></title><aug><au><cnm>INRArray</cnm></au></aug><pubdate>2005</pubdate><url>http://www.inra.fr/internet/Centres/toulouse/pharmacologie/lpt.htm</url></bibl><bibl id="B17"><title><p>Some aspects of the spline smoothing approach to non-parametric regression curve fitting</p></title><aug><au><snm>Silverman</snm><fnm>B</fnm></au></aug><source>Journal of the Royal Statistical Society: Series B</source><pubdate>1985</pubdate><volume>47</volume><issue>1</issue><fpage>1</fpage><lpage>52</lpage></bibl><bibl id="B18"><title><p>Simultaneous non-parametric regressions of unbalanced longitudinal data</p></title><aug><au><snm>Besse</snm><fnm>P</fnm></au><au><snm>Cardot</snm><fnm>H</fnm></au><au><snm>Ferraty</snm><fnm>F</fnm></au></aug><source>Computational Statistics &amp; Data Analysis</source><pubdate>1997</pubdate><volume>24</volume><issue>3</issue><fpage>255</fpage><lpage>270</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1016/S0167-9473(96)00067-9</pubid><pubid idtype="pmpid" link="fulltext">21757463</pubid></pubidlist></xrefbib></bibl><bibl id="B19"><aug><au><snm>Seber</snm><fnm>GAF</fnm></au></aug><source>Multivariate Observations</source><publisher>John Wiley &amp; Sons, New York, NY, USA</publisher><pubdate>1984</pubdate></bibl><bibl id="B20"><title><p>Principal component analysis for clustering gene expression data</p></title><aug><au><snm>Yeung</snm><fnm>KY</fnm></au><au><snm>Ruzzo</snm><fnm>WL</fnm></au></aug><source>Bioinformatics</source><pubdate>2001</pubdate><volume>17</volume><issue>9</issue><fpage>763</fpage><lpage>774</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1093/bioinformatics/17.9.763</pubid><pubid idtype="pmpid" link="fulltext">11590094</pubid></pubidlist></xrefbib></bibl><bibl id="B21"><title><p>Clustering microarray data</p></title><aug><au><snm>Chipman</snm><fnm>H</fnm></au><au><snm>Hastie</snm><fnm>TJ</fnm></au><au><snm>Tibshirani</snm><fnm>T</fnm></au></aug><source>Statistical Analysis of Gene Expression Microarray Data</source><publisher>Chapmann &amp; Hall/CRC Press, Boca Raton, Fla, USA</publisher><editor>Speed T</editor><pubdate>2003</pubdate><fpage>159</fpage><lpage>200</lpage></bibl><bibl id="B22"><title><p>Peroxisome proliferator-activated receptor <inline-formula><graphic file="1687-4153-2007-70561-i3.gif"/></inline-formula> mediates the adaptive response to fasting</p></title><aug><au><snm>Kersten</snm><fnm>S</fnm></au><au><snm>Seydoux</snm><fnm>J</fnm></au><au><snm>Peters</snm><fnm>JM</fnm></au><au><snm>Gonzalez</snm><fnm>FJ</fnm></au><au><snm>Desvergne</snm><fnm>B</fnm></au><au><snm>Wahli</snm><fnm>W</fnm></au></aug><source>Journal of Clinical Investigation</source><pubdate>1999</pubdate><volume>103</volume><issue>11</issue><fpage>1489</fpage><lpage>1498</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1172/JCI6223</pubid><pubid idtype="pmcid">408372</pubid><pubid idtype="pmpid" link="fulltext">10359558</pubid></pubidlist></xrefbib></bibl><bibl id="B23"><title><p>Peroxisome proliferator-activated receptor <inline-formula><graphic file="1687-4153-2007-70561-i4.gif"/></inline-formula> target genes</p></title><aug><au><snm>Mandard</snm><fnm>S</fnm></au><au><snm>M&#252;ller</snm><fnm>M</fnm></au><au><snm>Kersten</snm><fnm>S</fnm></au></aug><source>Cellular and Molecular Life Sciences</source><pubdate>2004</pubdate><volume>61</volume><issue>4</issue><fpage>393</fpage><lpage>416</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1007/s00018-003-3216-3</pubid><pubid idtype="pmpid" link="fulltext">14999402</pubid></pubidlist></xrefbib></bibl><bibl id="B24"><title><p>Starvation response in mouse liver shows strong correlation with life-span-prolonging processes</p></title><aug><au><snm>Bauer</snm><fnm>M</fnm></au><au><snm>Hamm</snm><fnm>AC</fnm></au><au><snm>Bonaus</snm><fnm>M</fnm></au><etal/></aug><source>Physiological Genomics</source><pubdate>2004</pubdate><volume>17</volume><issue>2</issue><fpage>230</fpage><lpage>244</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1152/physiolgenomics.00203.2003</pubid><pubid idtype="pmpid">14762175</pubid></pubidlist></xrefbib></bibl></refgrp>
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