Microarray technologies allow the identification of large numbers of expression differences within and between species. Although environmental and physiological stimuli are clearly responsible for changes in the expression levels of many genes, it is not known whether the majority of changes of gene expression fixed during evolution between species and between various tissues within a species are caused by Darwinian selection or by stochastic processes. We find the following: (1) expression differences between species accumulate approximately linearly with time; (2) gene expression variation among individuals within a species correlates positively with expression divergence between species; (3) rates of expression divergence between species do not differ significantly between intact genes and expressed pseudogenes; (4) expression differences between brain regions within a species have accumulated approximately linearly with time since these regions emerged during evolution. These results suggest that the majority of expression differences observed between species are selectively neutral or nearly neutral and likely to be of little or no functional significance. Therefore, the identification of gene expression differences between species fixed by selection should be based on null hypotheses assuming functional neutrality. Furthermore, it may be possible to apply a molecular clock based on expression differences to infer the evolutionary history of tissues.
A neutral model of transcriptome evolution.
Sex, Age, Specimen part, Disease, Disease stage
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General detoxification and stress responses are mediated by oxidized lipids through TGA transcription factors in Arabidopsis.
No sample metadata fields
View Samples12-oxo-phytodienoic acid (OPDA) and phytoprostane A1 (PPA1) are cyclopentenone oxylipins that are formed via the enzymatic
General detoxification and stress responses are mediated by oxidized lipids through TGA transcription factors in Arabidopsis.
No sample metadata fields
View Samples12-Oxo-phytodienoic acid (OPDA) and several phytoprostanes are structurally related cyclopentenone oxylipins that can be formed via the enzymatic jasmonate pathway and a non-enzymatic, free radical-catalyzed pathway, respectively. To elucidate the biological activities of phytoprostanes in comparison to OPDA as well as the metabolism we performed genome-wide expression analysis.
General detoxification and stress responses are mediated by oxidized lipids through TGA transcription factors in Arabidopsis.
No sample metadata fields
View SamplesNonsyndromic clefts of the palate and/or lip are common birth defects arising in about 1/700 live births worldwide. They are caused by multiple genetic and environmental factors, can only be corrected surgically and require complex post-operative care that imposes significant burdens on individuals and society. Our understanding of the molecular networks that control palatogenesis has advanced through studies on mouse genetic models of cleft palate. In particular, the transcription factor Pax9 regulates palatogenesis through the Bmp, Fgf and Shh pathways in mice. But there is still much to learn about Pax9's relationship with other signaling pathways in this process. Expression analyses and unbiased gene expression profiling studies offer a molecular explanation for the resolution of palatal defects by showing that Wnt and Eda/Edar-related genes are expressed in normal palatal tissues and that the Wnt and Eda/Edar signaling pathway is downstream of Pax9 in palatogenesis. Overall design: E13.5 mouse embryos palate were micro-dissceted, control and mutant samples were seperated and individually lyzed for the RNA extraction.
Small-molecule Wnt agonists correct cleft palates in <i>Pax9</i> mutant mice <i>in utero</i>.
Specimen part, Cell line, Treatment, Subject
View SamplesNonsyndromic clefts of the palate and/or lip are common birth defects arising in about 1/700 live births worldwide. They are caused by multiple genetic and environmental factors, can only be corrected surgically and require complex post-operative care that imposes significant burdens on individuals and society. Our understanding of the molecular networks that control palatogenesis has advanced through studies on mouse genetic models of cleft palate. In particular, the transcription factor Pax9 regulates palatogenesis through the Bmp, Fgf and Shh pathways in mice. But there is still much to learn about Pax9''s relationship with other signaling pathways in this process. Here we show alterations of Wnt expression and decreased Wnt activity in Pax9-/- palatal shelves are a likely result of Pax9''s ability to directly bind and repress the promoters of Dkk1 and Dkk2, proteins that antagonize Wnt signaling. We exploited this relationship by delivering small-molecule Dkk inhibitors into the tail-veins of pregnant Pax9+/- females from E10.5 to E14.5. Such therapies restored Wnt signaling, promoted cell proliferation, bone formation and fusion of palatal shelves in Pax9-/- embryos. These data uncover a connection between the roles of Pax9 and Wnt genes in palatogenesis and offer a new approach for treating human cleft palates. Overall design: E14 embryos of Pax9-/- and control littermates with or without WAY-262611 treatment, mouse embryos palate were micro-dissected, control and mutant samples were separated and individually lysed for the RNA extraction.
Small-molecule Wnt agonists correct cleft palates in <i>Pax9</i> mutant mice <i>in utero</i>.
Specimen part, Cell line, Treatment, Subject
View SamplesLoss of Syk in normal breast cells in vivo and in vitro: gene expression and phenotypic switch to stem-cell like with induction of invadopodia
Tumor suppressor function of Syk in human MCF10A in vitro and normal mouse mammary epithelium in vivo.
Cell line
View SamplesEngineering of genetically encoded calcium indicators predominantly focused on optimizing fluorescence changes, but effects of indicator expression on host organisms have largely not been addressed. Here, we report biocompatibility and wide-spread functional expression of the genetically encoded calcium indicator TN-XXL in a transgenic mouse model. To validate the model and to characterize potential effects of indicator expression we assessed both indicator function and a variety of host parameters such as anatomy, physiology, behavior and gene expression profiles in these mice. We also demonstrate the usefulness of primary cell types and organ explants prepared from these mice for imaging applications. While we do find mild signatures of indicator expression that may guide further indicator development the green indicator mice generated provide a well characterized resource of primary cells and tissues for in vitro and in vivo calcium imaging applications.
Biocompatibility of a genetically encoded calcium indicator in a transgenic mouse model.
Specimen part
View SamplesMesoderm differentiation in zebrafish relies on a complex interaction between transcription factors and signaling pathways. Tbx16 is a t-box transcription factor involved in this interaction. Here, we examine downstream targets of tbx16 in the intermediate mesoderm at the 4/5-somite stage and tail mesoderm at the 21-somite stage by comparing wild-type tissues with tissues from the tbx16 mutant, spadetail (spt).
Spatio-temporal regulation of Wnt and retinoic acid signaling by tbx16/spadetail during zebrafish mesoderm differentiation.
No sample metadata fields
View SamplesTranscript levels of barley genes were examined in the wheat-barley chromosome addition lines having one of six barley chromomes, 2H, 3H, 4H, 5H, 6H and 7H. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Seungho Cho. The equivalent experiment is BB8 at PLEXdb.]
Transcriptome analysis and physical mapping of barley genes in wheat-barley chromosome addition lines.
Specimen part
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