Project description:Photoperiod and hormonal cues drive dramatic seasonal changes in structure and function of the avian song control system. Little is known, however, about the patterns of gene expression associated with seasonal changes. Here we address this issue by exposing GambelM-bM-^@M-^Ys white-crowned sparrows to season-appropriate cues and extracting RNA from the telencephalic song control nuclei HVC and RA across multiple time points that capture different stages of growth and regression. We chose HVC and RA because while both nuclei change in volume across seasons, the cellular mechanisms underlying these changes differ. We thus hypothesized that different genes would be expressed between HVC and RA. We tested this by using the extracted RNA to perform a cDNA microarray hybridization developed by the SoNG initiative. We then validated these results using qRT-PCR. Supporting our hypothesis, only 59 of the 363 genes of interest were found to vary by more than |1.5| fold in expression in both nuclei, while 132 gene expression changes were HVC specific and 172 genes were RA specific. We then assigned many of these genes to functional categories relevant to the different mechanisms underlying seasonal change in HVC and RA, including neurogenesis, apoptosis, cell growth, dendrite arborization and axonal growth, angiogenesis, endocrinology, growth factors, and electrophysiology. This revealed categorical differences in the kinds of genes regulated in HVC and RA. These results show that different molecular programs underlie seasonal changes in HVC and RA, and that gene expression is time specific across different reproductive conditions. Our results provide insights into the complex molecular pathways that underlie adult neural plasticity. Experimental groups: long-term Short Day (SD); Long Day (LD) with Testosterone (T) for 3, 7, and 21 days (3LD+T, 7LD+T, 21LD+T respectively); SD and removal of T at 1 and 2 days (1SD-T, 2SD-T); two tissues (HVC, RA) collected separately from each individual animal; one experimental sample and one universal SoNG reference sample per array; dye balanced within groups. Six biological replicates per group, five biological replicates in 3LD+T.HVC group.

Project description:Songbirds provide rich natural models for studying the relationships of brain anatomy, behavioral function, environmental signals and gene expression. Under the Songbird Neurogenomics Initiative, investigators from more than a dozen laboratories collected brain samples from six species of songbird under a range of experimental conditions, and 488 of these samples were analyzed systematically for gene expression by microarray. ANOVA was used to test 32 planned contrasts in the data, revealing the relative impact of different factors. The brain region from which tissue was taken had the greatest influence on gene expression profile, affecting the majority of signals measured by the 18,848 non-redundant cDNAs spotted on the microarray. Social and environmental manipulations had highly variable impact, ranging from nil in some cases to robust in others. Several specific genes were identified as points of interest in the evolution of mechanisms by which environmental signals influence behavior. The data were also analyzed using Weighted Gene Co-expression Network Analysis (WGCNA) followed by Gene Ontology (GO) analysis. This revealed modules of co-regulated genes that are also enriched for specific functional annotations such as M-bM-^@M-^\ribosomeM-bM-^@M-^] (expressed more highly in juvenile brain) and M-bM-^@M-^\dopamine metabolic processM-bM-^@M-^] (expressed more highly in striatal song control nucleus Area X). These results underscore the complexity of influences on neural gene expression and provide a resource for studying how these influences are integrated during natural experience. RNA samples were collected from six different songbird species (phylogeny in SI Appendix, Figure S1) and representing 80 different M-bM-^@M-^\treatmentsM-bM-^@M-^], i.e., combinations of species, brain region, sex, age, and behavioral state. The tissue samples were organized around 15 standalone experiments (Table 1 and SI Appendix, Table S1), contributed by investigators in a dozen different laboratories but analyzed under uniform conditions in a single laboratory as originally planned under the Songbird Neurogenomics Initiative. Each sample was hybridized to a zebra finch cDNA array along with a universal reference (a pool of zebra finch telencephalic RNA). e01: Brain regions HVC and RA were collected from Gambel's White crowned sparrows (Zonotrichia leucophrys gambelii) from the following experimental groups: long-term Short Day (SD); Long Day (LD) with Testosterone (T) for 3, 7, and 21 days (3LD+T, 7LD+T, 21LD+T respectively); SD and removal of T at 1 and 2 days (1SD-T, 2SD-T). Six biological replicates per group, five biological replicates in 3LD+T.HVC group. All samples were hybridized against the SoNG universal reference RNA pool.

Project description:The role of androgen in breast cancer development is not fully understood although androgen receptors (AR) have been identified in breast cancer clinical samples and cell lines. However the whole spectra of androgen actions cannot be accounted to the classic AR mode of action and the possible existence of a cell surface AR has been suggested. Indeed androgens like all steroids have been reported to trigger membrane initiated signaling activity and exert specific actions. Androgens acting on the membrane can rapidly activate kinase signaling pathways and ultimately could affect gene expression. However, the molecular nature of membrane androgen binding sites represents another major persisting question. In the present study, we investigated early transcriptional effects of testosterone and the impermeable testosterone-BSA conjugate, in two breast cancer cell lines, in an attempt to decipher specific genes modified in each case, providing evidences about specific membrane initiating actions. Our data indicate that the two agents tested affect the expression of several genes. A group of genes were commonly affected while others were uniquely modified by each agent. In MDA-MB-231 cells, that are AR negative, the majority of genes affected by testosterone were also affected by testosterone-BSA indicating a membrane action. Subsequent analysis revealed that the two agents trigger different molecular pathways and cellular/molecular functions, suggestive of a molecular heterogeneity of membrane and intracellular AR. In addition, the phenotypic interactions of membrane-acting androgen with growth factor were verified at the transcriptomic level. Finally an interesting interplay between membrane-acting androgen with inflammation-related molecules, with potential clinical implications was revealed. Experiment Overall Design: Cell lines and culture conditions Experiment Overall Design: The hormone-sensitive breast cancer cell line T47D (expressing ERÎ±, ERÎ² and AR) and the hormone insensitive breast cancer cell line MDA-MB-231 (expressing only ERÎ²) were purchased from the European Collection of Cell Cultures (Salisbury, UK). T47D cells and MDA-MB-231 were cultured in RPMI-1640 medium, supplemented with 10% charcoal treated fetal bovine serum (FBS), in a humidified atmosphere of 5% CO2 in air, at 37Â°C. Culture media and serum were from Gibco BRL (Life Technologies, Paisley, UK). Experiment Overall Design: Treatment- Gene expression assay Experiment Overall Design: Cells were serum starved for 6 hours and then treated with 10-7M Testosterone or charcoal-treated Testosterone-BSA, for 3 hours. Total RNA was isolated using Nucleospin II columns (Macheray-Nagel, DÃ¼ren, Germany), labeled and hybridized according to the Affymetrix protocol (Affymetrix Gene-Chip Expression Analysis Technical Manual), using the HGU133A plus 2 chip, analyzing a total of 54675 transcripts. Signals were detected by an Affymetrix microarray chip reader.

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Transcriptomic response of red grouse to gastro-intestinal nematode parasites and testosterone

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