Seed dormancy is the inability for seeds to germinate even under favorable conditions. In the Arabidopsis Landsberg <i>erecta</i> (L<i>er</i>) ecotype, 2 weeks of dry storage, called after-ripening, is sufficient to relieve seed dormancy. Such seed is referred to as after-ripened (AR) and has a high rate of germination when imbibed. While widespread transcriptome changes have been previously observed with seed dormancy loss, this experiment was designed to characterize transcriptional changes associated with the increased seed dormancy and dormancy loss of the gibberellin (GA) hormone-insensitive <i>sleepy1-2</i> (<i>sly1-2</i>) mutant. The <i>SLY1</i> gene encodes the F-box subunit of an SCF E3 ubiquitin ligase needed for GA-triggered proteolysis of DELLA repressors of seed germination. In the <i>sly1-2</i> mutant, GA-directed DELLA proteolysis cannot occur leading to DELLA protein accumulation and increased dormancy. <i>sly1-2</i> mutant seeds are fully dormant at 2 weeks of dry storage (0% germination), but germinate well with very long after-ripening (51% germination after 19 months). <i>sly1-2</i> seed germination can also be rescued by overexpression of the GA receptor, <i>GA-INSENSITIVE DWARF1b</i> (<i>GID1b-OE</i>), which resulted in 74% germination at 2 weeks of dry storage. In this experiment, we compared seeds of wild-type L<i>er</i> at 2 weeks of dry storage (non-dormant), dormant <i>sly1-2</i> (2 weeks of dry storage; <i>sly1-2</i>(D)), long after-ripened <i>sly1-2</i> (non-dormant, 19 months of dry storage; <i>sly1-2</i>(AR)), and <i>sly1-2 GID1b-OE</i> (non-dormant, 2 weeks of dry storage). Samples were collected at two imbibition timepoints: 1) a 0h timepoint after 4 days at 4°C, and 2) a 12h timepoint after 4 days at 4°C followed by 12 hours in the light at 22°C. These timepoints were selected to capture the transcriptomes at an early and late time in Phase II of imbibition. Using this experimental design we were able to determine transcriptome differences associated with seed dormancy in the <i>sly1-2</i> mutation (L<i>er</i> wt vs <i>sly1-2</i>(D)), and changes associated with <i>sly1-2</i> dormancy loss through dry after-ripening (<i>sly1-2</i>(AR) vs <i>sly1-2</i>(D)) or through <i>GID1b</i>-overexpression (<i>sly1-2 GID1b-OE</i> vs <i>sly1-2</i>(D)). Seeds for L<i>er</i> wt, <i>sly1-2</i>(D), and <i>sly1-2 GID1b-OE</i> were grown alongside each other under the same conditions and after-ripened for 2 weeks. Seeds from <i>sly1-2</i>(AR) were grown under the same conditions in advance of the other lines to allow for the long after-ripening requirement. RNA was extracted using a phenol-chloroform-based extraction from three biological replicates per treatment.
Transcriptional mechanisms associated with seed dormancy and dormancy loss in the gibberellin-insensitive sly1-2 mutant of Arabidopsis thaliana.
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Specimen part, Time
View SamplesPlant embryos can survive years in a desiccated, quiescent state within seeds. In many species, seeds are dormant and unable to germinate at maturity. They acquire the capacity to germinate through a period of dry storage called after-ripening (AR), a biological process that occurs at 5-15% moisture when most metabolic processes cease. Because stored transcripts will be among the first proteins translated upon water uptake, they likely impact germination potential. Transcriptome changes associated with the increased seed dormancy of the GA-insensitive <i>sly1-2</i> mutant, and with dormancy loss through <i>sly1-2</i> after-ripening or constitutive overexpression of the GA receptor (GID1b) were characterized in dry seeds. This experiment used the same seed batches as a previous experiment (E-MTAB-4782) to characterize transcriptional changes associated with the increased seed dormancy and dormancy loss in imbibing seeds. The <i>SLY1</i> gene encodes the F-box subunit of an SCF E3 ubiquitin ligase needed for GA-triggered proteolysis of DELLA repressors of seed germination. In the <i>sly1-2</i> mutant, GA-directed DELLA proteolysis cannot occur leading to DELLA protein accumulation and increased dormancy. <i>sly1-2</i> mutant seeds are fully dormant at 2 weeks of dry storage (0% germination), but germinate well with very long after-ripening (51% germination after 19 months). <i>sly1-2</i> seed germination can also be rescued by overexpression of the GA receptor, <i>GA-INSENSITIVE DWARF1b</i> (<i>GID1b-OE</i>), which resulted in 74% germination at 2 weeks of dry storage. In this experiment, we sampled dry seeds of wild-type L<i>er</i> at 2 weeks of dry storage (non-dormant), dormant <i>sly1-2</i> (2 weeks of dry storage; <i>sly1-2</i>(D)), long after-ripened <i>sly1-2</i> (non-dormant, 19 months of dry storage; <i>sly1-2</i>(AR)), and <i>sly1-2 GID1b-OE</i> (non-dormant, 2 weeks of dry storage). This experimental design allowed comparison between these transcriptomes in dry seeds to determine if dry seed stored mRNA differences contribute to the dormancy phenotypes observed once seeds are imbibed. Seeds for L<i>er</i> wt, <i>sly1-2</i>(D), and <i>sly1-2 GID1b-OE</i> were grown alongside each other under the same conditions and after-ripened for 2 weeks. Seeds from <i>sly1-2</i>(AR) were grown under the same conditions in advance of the other lines to allow for the long after-ripening requirement. RNA was extracted using a phenol-chloroform-based extraction from three biological replicates per treatment.
Biology in the Dry Seed: Transcriptome Changes Associated with Dry Seed Dormancy and Dormancy Loss in the Arabidopsis GA-Insensitive sleepy1-2 Mutant
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Specimen part
View SamplesWIN 18,446/RA treatment of neonatal mice was used to synchronize the initial wave of spermatogenesis and identify novel messages expressed within either germ or Sertoli cells as spermatogonia enter meiosis.
Riding the spermatogenic wave: profiling gene expression within neonatal germ and sertoli cells during a synchronized initial wave of spermatogenesis in mice.
Specimen part
View SamplesMurine testis developmental time course created from tissue samples collected from birth through adulthood and hybridized to MGU74v2 A, B, and C chips in duplicate
The murine testicular transcriptome: characterizing gene expression in the testis during the progression of spermatogenesis.
No sample metadata fields
View SamplesThis study describes a temporal profile of gene expression from normal human fetal testes and ovaries. Gonads from 34 fetuses between 9 weeks and 20 weeks of gestation were obtained from the Department of Pathology and the Birth Defects Research Laboratory at the University of Washington. Relative transcript levels were determined using the Affymetrix Human Genome U133A Plus 2.0 arrays.
Global gene expression in the human fetal testis and ovary.
Specimen part
View SamplesAnalysis of Sertoli and Leydig cell translatome utilizing an in vivo ribosome tagging strategy (RiboTag) that allows a detailed and physiologically relevant characterization of the polysome-associated mRNAs in vivo. Although progress has been made in the identification of specific transcripts that are translated in Sertoli and Leydig cells and their response to hormones, efforts to expand these studies have been restricted by technical hurdles. Our analysis identified all previously characterized Leydig and Sertoli cell-specific markers and identified in a comprehensive manner novel markers of Leydig and Sertoli cells; the translational response of these two cell types to gonadotropins or testosterone was also investigated.
No associated publication
Specimen part, Disease, Treatment
View SamplesTime course of gene expression in the murine embryonic testis from the time of the indifferent gonad (11.5dpc) to birth (18.5dpc)
Profiling gene expression during the differentiation and development of the murine embryonic gonad.
No sample metadata fields
View SamplesTime course of gene expression in the murine embryonic ovary from the time of the indifferent gonad (11.5dpc) to birth (18.5dpc)
Profiling gene expression during the differentiation and development of the murine embryonic gonad.
No sample metadata fields
View SamplesIn Arabidopsis, jasmonate is required for stamen and pollen maturation. Mutants deficient in jasmonate synthesis, such as opr3, are male-sterile but become fertile when jasmonate is applied to developing flower buds. We have used ATH1 oligonucleotide arrays to follow gene expression in opr3 stamens for 22 hours following jasmonate treatment. In these experiments, a total of 821 genes were specifically induced by jasmonate and 480 repressed. Comparisons with data from previous studies indicate that these genes constitute a stamen-specific jasmonate transcriptome, with a large proportion (70%) of the genes expressed in the sporophytic tissue but not in the pollen. Bioinformatics tools allowed us to associate many of the induced genes with metabolic pathways that are likely up-regulated during jasmonate-induced maturation. Our pathway analysis led to the identification of specific genes within larger families of homologues that apparently encode stamen-specific isozymes. Extensive additional analysis of our dataset identified 13 transcription factors that may be key regulators of the stamen maturation processes triggered by jasmonate. Two of these transcription factors, MYB21 and MYB24, are the only members of subgroup 19 of the R2R3 family of MYB proteins. A myb21 mutant obtained by reverse genetics exhibited shorter anther filaments, delayed anther dehiscence and greatly reduced male fertility. A myb24 mutant was phenotypically wild type, but production of a myb21myb24 double mutant indicated that introduction of the myb24 mutation exacerbated all three aspects of the myb21 phenotype. Exogenous jasmonate could not restore fertility to myb21 or myb21myb24 mutant plants. Together with the data from transcriptional profiling, these results indicate that MYB21 and MYB24 are induced by jasmonate and mediate important aspects of the jasmonate response during stamen development.
Transcriptional regulators of stamen development in Arabidopsis identified by transcriptional profiling.
No sample metadata fields
View SamplesThe tissues of the male reproductive tract are characterized by distinct morphologies, ranging from highly coiled to un-coiled. Global gene expression profiles of the efferent ducts, epididymis, and vas deferens were generated from embryonic day 14.5 to postnatal day 1, the period when gross morphological changes are initiated and tissue-specific morphologies emerge. Expression profiles of homeobox genes, as potential regionalization factors, were examined. Tissue transcriptome comparison identified two expression profiles of interest: genes similar between the epididymis and vas deferens early in development but dissimilar later and genes dissimilar between the epididymis and efferent duct early but similar later. Ontology analysis demonstrated cell adhesion-associated genes to be highly enriched in both comparisons. This work identified several potential regulators of cell adhesion along the tract and indicates cell adhesion may be modulated in a tissue-specific manner, playing an important role in the establishment of each tissues final morphology.
No associated publication
Sex, Specimen part
View Samples