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Dataset Details (GSE25841)

Superfund Research Program

Title: Evolutionary Diversification of Duplicated Genes; Experiment A

Accession Number: GSE25841

Link to Dataset:

Repository: Gene Expression Omnibus (GEO)

Data Type(s): Gene Expression

Experiment Type(s): Expression profiling by array

Organism(s): Daphnia pulex

Summary: This study measured the rates at which duplicated genes in the Daphnia pulex genome diverge in function, based on significant differences in their gene expression when paralogs of various ages were tested across 8 to 12 contrasting conditions. The conditions were designated A to L. The number and diversity of experiments were designed to uncover condition-specific expression. The age of duplicated genes was measured as the level of silent-site nucleotide substitution (Ks) between paralogs. Two methods were used to evaluate the degree to which expression pattern of paralogs differ. (1) The first method investigated variation in the differential expression patterns among duplicates of individual gene families by calculating the M values (log2 treatment – log2 reference) from eight experiments, then calculating Pearson correlations. (2) The second method is a global investigation which defined a distinguishable expression pattern by a significance criterion (p < 0.05) using ANOVA for the simple statistical model of aov( Yab ~ Xab ), for matrices Yab differential expression M values and Xab gene factors, with replicates. We used pr(M) < 0.05 as criterion that expression differs between paralog genes, for zero to twelve treatments. The hypothesis that is tested is one of how many paralog pairs in each Ks category reach the criterion of a distinguishable expression pattern, which is tested for significance with Fisher's exact test for count data. This method is reliable for as few as two probes for one gene and one probe for the other, although a greater number of replicate probes produced more significant results.

Publication(s) associated with this dataset:
  • Pfrender ME, Gilbert D, Thomas W, Tucker A, Oakley TH, Tokishita S, Aerts A, Arnold GJ, Basu MK, Bauer DJ, Caceres CE, Carmel L, Casola C, Choi J, Detter JC, Dong Q, Dusheyko S, Eads BD, Frohlich T, Geiler-Samerotte KA, Gerlach D, Hatcher P, Jogdeo S, Krijgsveld J, Kriventseva EV, Kültz D, Laforsch C, Lindquist E, Lopez J, Manak J, Muller J, Pangilinan J, Patwardhan RP, Pitluck S, Pritham EJ, Rechtsteiner A, Rho M, Rogozin IB, Sakarya O, Salamov A, Schaack S, Shapiro H, Shiga Y, Skalitzky C, Smith Z, Souvorov A, Sung W, Tsuchiya D, Tu H, Vos H, Wang M, Wolf YI, Yamagata H, Yamada T, Ye Y, Shaw JR, Andrews J, Crease TJ, Tang H, Lucas SM, Robertson HM, Bork P, Koonin EV, Zdobnov EM, Grigoriev IV, Lynch M, Boore JL, Colbourne JK. 2011. The ecoresponsive genome of Daphnia pulex. Science 331(6017):555-561. doi:10.1126/science.1197761 PMID:21292972 PMCID:PMC3529199
Project(s) associated with this dataset:
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