Project description:Drosophila melanogaster undergoes a complete metamorphosis, during which time the larval male and female forms transition into sexually dimorphic, reproductive adult forms. To understand this complex morphogenetic process at a molecular-genetic level, we performed whole genome microarray analyses. Genes were identified that were expressed during metamorphosis in both somatic and germline tissues of males and females. Additionally, genes were identified that display sex-specific differences in abundance in both of these tissues at discrete times during metamorphosis. Keywords: time course; wild type; genetic modification;
Project description:The veined rapa whelk (Rapana venosa) is widely consumed in China but is also a predator that is reducing bivalves resources in oceans worldwide. Larval metamorphosis of this species, a pelagic to benthic transition that involves considerable structural and physiological changes, plays a pivotal role in its commercial breeding and natural populations. Thus, the endogenous microRNA that drive this transition attract considerable interest. This study is the first to investigate alterations of miRNA expression during metamorphosis in a marine gastropod by using high-throughput sequencing. A total of 195 differentially expressed miRNAs were obtained, including 65 miRNAs differentially expressed during the transition from pre-competent larva to competent larva (33 up-regulated and 32 down regulated) and 123 miRNAs differentially expressed during competent to post larva transition (96 up-regulated and 27 down regulated). Our data improve understanding of the microRNA function into R. venosa metamorphosis and provide a solid basis for further study.
Project description:Chromatin accessibility, histone modifications and transcription factor binding are highly dynamic during Drosophila metamorphosis and drive global changes in gene expression as larval tissues differentiate into adult structures. Unfortunately, the presence of pupa cuticle on many Drosophila tissues during metamorphosis prevents enzyme access to cells and has limited the use of enzymatic in situ methods for assessing chromatin accessibility and histone modifications. Here, we present a dissociation method for cuticle-bound pupal tissues that is optimized for use with ATAC-Seq and CUT&RUN to interrogate chromatin accessibility and histone modifications. We show this method provides comparable chromatin accessibility data to the non-enzymatic approach FAIRE-seq, with only a fraction of the amount of input tissue required. This approach is also compatible with CUT&RUN, which allows genome-wide mapping of histone modifications with less than 1/10th of the tissue input required for more conventional approaches such as Chromatin Immunoprecipitation Sequencing (ChIP-seq). Our protocol makes it possible to use newer, more sensitive enzymatic in situ approaches to interrogate gene regulatory networks during Drosophila metamorphosis.
Project description:Larval settlement and metamorphosis is a vital transition period for marine invertebrates and can have far-reaching effects on the ecology and evolution of a species. To explore the molecular mechanisms of this critical process in a non-model organism, the tropical abalone Haliotis asinina, we employed cDNA microarray methods. By comparing gene expression profiles through mid to late larval development and metamorphosis, we identified 144 genes as likely candidates for a role in competence and/or metamorphosis. Gene characterization showed that ~60% of these were significantly similar to previously described genes from other taxa, while ~40% had no significant similarities to any known genes. A high 49.3% of genes were gastropod- or abalone-specific, but none appear to be Lophotrochozoan-specific, despite the fact that metamorphosis is thought to have had a separate origin in this group. Based on temporal expression profiles, the differentially expressed larval and postlarval genes can be clustered into 5 categories that reveal there are strikingly different transcriptional patterns occurring during this phase of development. Some classes of gene activation are contingent upon exogenous cues and correlate with the initiation of settlement and metamorphosis. Importantly, there is also extensive gene activity associated with the endogenous attainment of competence, which occurs prior to, and independent of, the exogenous induction of settlement. Our results show that as the haliotid veliger larva matures, it requires the coordinated regulation of temporally different batteries of genes involved in a wide range of physiological and developmental processes associated with colonisation of the benthos. Although the signalling pathways operating at metamorphosis may be conserved across the animal kingdom, it appears they are regulating the expression of novel genes specific to abalone, gastropods and molluscs during H. asinina metamorphosis. Keywords: timecourse; metamorphosis; marine ecology