Project description:We applied an iTRAQ-based quantitative proteomic approach to compare the protein expressionprofiles of Skeletonema dohrnii grown in lower silicate and temperature conditions.
Project description:We applied an iTRAQ-based quantitative proteomic approach to understand the differential proteome expression of marine diatom Skeletonema dohrnii grown in different temperature and silicate concentration.
Project description:Medusae of Turritopsis dohrnii undergo reverse development in response to physical damage, adverse environmental conditions, or aging. Senescent, weakened or damaged medusae transform into a cluster of poorly differentiated cells (known as the cyst stage), which metamorphose back into a preceding life cycle stage, the polyp. During the metamorphosis, cell transdifferentiation occurs. The cyst represents the intermediate stage between a reverting medusa and a healthy polyp, during which cell transdifferentiation and tissue reorganization take place. Here we characterize and compare the transcriptomes of the polyp and newborn medusa stages of T. dohrnii with that of the cyst, to identify biological networks potentially involved in the reverse development and transdifferentiation processes. The polyp, medusa and cyst of T. dohrnii were sequenced through Illumina RNA-sequencing and assembled using a de novo approach, resulting in 92,569, 74,639 and 86,373 contigs, respectively. The transcriptomes were annotated and comparative analyses among the stages identified biological networks that were significantly over-and under-expressed in the cyst as compared to the polyp and medusa stages. Biological processes that occur at the cyst stage such as telomerase activity, regulation of transposable elements and DNA repair systems, and suppression of cell signaling pathways, mitotic cell division and cellular differentiation and development may be involved in T. dohrnii's reverse development and transdifferentiation. Our results are the first attempt to understand T. dohrnii's life-cycle reversal at the genetic level, and indicate possible avenues of future research on developmental strategies, cell transdifferentiation, and aging using T. dohrnii as a non-traditional in vivo system.
| S-EPMC6893190 | biostudies-literature
Project description:RNA-sequencing for Turritopsis dohrnii
Project description:Only two hydromedusan species, Turritopsis dohrnii and T. sp., have exhibited experimental multiple-repeat life cycle reversion in the laboratory, which can be artificially induced by various means such as incubation with CsCl, heat shock, and mechanical damage with needles. In the present study, we constructed a genome assembly of T. dohrnii using Pacific Biosciences long-reads and Illumina short-reads, for which the genome DNA was extracted from 1,500 young medusae originated from a single clone. The total length of the draft genome sequence of T. dohrnii was 435.9 Mb (N50 length 747.2 kb). We identified 23,314 high-confidence genes and found the characteristics of RNA expression amongst developmental stages. Our genome assembly and transcriptome data provide a key model system resource that will be useful for understanding cyclical rejuvenation.
Project description:Global warming is expected to reduce the nutrient concentration in the upper ocean and affect the physiology of marine diatoms, but the underlying molecular mechanisms controlling these physiological changes are currently unknown. To understand these mechanisms, here we investigated iTRAQ based proteomic profiling of diatom Skeletonema dohrnii in a multifactorial experimental with a combining change of temperature and silicate concentrations. In total, 3369 differently abundant proteins were detected in four different environmental conditions, and the function of all proteins was identified using Gene Ontology and KEGG pathway analysis. For discriminating the proteome variation among samples, multivariate statistical analysis (PCA, PLS-DA) was performed by comparing the protein ratio differences. Further, performing pathway analysis on diatom proteomes, we here demonstrated downregulation of photosynthesis, carbon metabolism, and ribosome biogenesis in the cellular process that leads to decrease the oxidoreductase activity and affects the cell cycle of the diatom. Using PLS-DA VIP score plot analysis, we identified 15 protein biomarkers for discriminating studied samples. Of these, five proteins or gene (rbcL, PRK, atpB, DNA-binding, and signal transduction) identified as key biomarkers, induced by temperature and silicate stress in diatom metabolism. Our results show that proteomic finger-printing of S. dohrnii with different environmental conditions adds biological information that strengthens marine phytoplankton proteome analysis.