Project description:Time course analysis series in Development of the transcriptome from Drosophila melanogaster using the Heidelberg FlyArray. All stages were hybridized against embryonic stage 0-4 h as reference control. Keywords: time-course
Project description:gene expression was measured in control and heat resistance selected adult female flies before and at 8 time points after heat stress for 1h @ 36 degrees Abstract The availability of full genome sequences has allowed the construction of microarrays, with which screening of the full genome for changes in gene expression is possible. This method can provide a wealth of information about biology at the level of gene expression and is a powerful method to identify genes and pathways involved in various processes. In this study, we report a detailed analysis of the full heat stress response in Drosophila melanogaster females, using whole genome gene expression arrays (Affymetrix Inc, Santa Clara, CA, USA). The study focuses on up- as well as downregulation of genes from just before and at 8 time points after an application of short heat hardening (368C for 1 hour). The expression changes were followed up to 64 hours after the heat stress, using 4 biological replicates. This study describes in detail the dramatic change in gene expression over time induced by a short-term heat treatment. We found both known stress responding genes and new candidate genes, and processes to be involved in the stress response. We identified 3 main groups of stress responsive genes that were early–upregulated, early– downregulated, and late–upregulated, respectively, among 1222 differentially expressed genes in the data set. Comparisons with stress sensitive genes identified by studies of responses to other types of stress allow the discussion of heat-specific and general stress responses in Drosophila. Several unexpected features were revealed by this analysis, which suggests that novel pathways and mechanisms are involved in the responses to heat stress and to stress in general. The majority of stress responsive genes identified in this and other studies were downregulated, and the degree of overlap among downregulated genes was relatively high, whereas genes responding by upregulation to heat and other stress factors were more specific to the stress applied or to the conditions of the particular study. As an expected exception, heat shock genes were generally found to be upregulated by stress in general. Keywords: Time series
Project description:Discovery of progenitor signatures by time series synexpression analysis during Drosophila cell immortalization [Microarray Expression]
Project description:Gene expression changes in response to aging compared to heat stress, oxidative stress and ionizing radiation in Drosophila melanogaster
Project description:The notion that genes are the sole units of heredity and that a barrier exists between soma and germline has been a major hurdle in elucidating the heritability of traits that were observed to follow a non-Mendelian inheritance pattern. It was only after the conception of “epigenetics” by C. H. Waddington that the effect of parental environment on subsequent generations via non-DNA sequence-based mechanisms, such as DNA methylation, chromatin modifications, non-coding RNAs and proteins, could be established in various organisms, now referred to as multigenerational epigenetic inheritance. Despite the growing body of evidence, the male gamete-derived epigenetic factors that mediate the transmission of such phenotypes are seldom explored, particularly in the model organism Drosophila melanogaster. Using the heat stress-induced multigenerational epigenetic inheritance paradigm in a widely used position-effect variegation line of Drosophila, named white-mottled, we have dissected the effect of heat stress on the sperm proteome in the current study. We demonstrate that multiple successive generations of heat stress at the early embryonic stage results in a significant downregulation of proteins associated with translation, chromatin organization, microtubule-based processes, and generation of metabolites and energy in the Drosophila sperms. Based on our findings, we propose chromatin-based epigenetic mechanisms, a well-established mechanism for environmentally induced multigenerational effects, as a plausible way of transmitting heat stress memory via the male germ line in subsequent generations. Moreover, we demonstrate the effect of multiple generations of heat stress on the reproductive fitness of Drosophila, shedding light on the adaptive or maladaptive potential of heat stress-induced multigenerational phenotypes.
Project description:A study evaluating the effect of stress resistance selection of Drosophila melanogaster. Abstract Here, we report a detailed analysis of changes in gene expression in Drosophila melanogaster selected for multiple eological relevant environmental stress resistance traits. We analyzed females from three biological replicates from seven selection regimes and one control regime using whole genome gene expression arrays. Replicated selection lines were selected for resistance to acute heat survival, high temperature knock down, constant 30°C during development, cold shock survival, desiccation and starvation, respectively. Additionally, a set of replicated lines was selected for increased longevity. When compared to gene expression profiles of control lines, we were able to detect consistent selection responses at the transcript level in each specific selection regime and also found a group of differentially expressed genes that were generally changed among all selected lines. Replicated selection lines clustered together, i.e. showed similar changes in gene expression (compared to controls) and thus showed that 10 generations of artificial selection gives a clear signal among gene expression profiles. The changes in gene expression in lines selected for increased longevity, desiccation and starvation resistance, respectively, showed high similarities. Cold resistance selected lines showed little differentiation from controls. Different methods of heat selection (heat survival, heat knock down and constant 30°C) showed little similarity verifying that different mechanism are involved in high temperature adaptation. The direction of change in gene expression in the selected lines showed a consistent pattern for each selection regime. For most selection regimes and in the comparison of all selected lines and controls exclusively up- or down regulation of gene expression among significant differentially expressed genes was found. The different responses to selection expressed in individual selection regimes and among all selected lines indicate that we have identified genes involved in stress specific and general stress response mechanisms. Keywords: control versus selected