2017 Fiscal Year Research-status Report
Molecular basis of immortality-to-mortality switch in the life cycle of Cnidaria
| Project/Area Number |
17K07420
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
ハルトゥーリン コンスタンチン 沖縄科学技術大学院大学, マリンゲノミックスユニット, 研究員 (80725458)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | Aurelia / metamorphosis / Cnidaria / immortality |
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| Outline of Annual Research Achievements |
Research project proceeded strictly according to the research plan for FY2017.
(1) Seven types of samples which represent polyp-to-jellyfish
transition (P1,S1-4) as well as jellyfishes of different age (J1,J2) were successfully collected, their transcriptomes were sequenced and mapped to the Aurelia genome. (2) Differential genes (1231 polyp-specific and 2487 jellyfish-specific) were identified. (3) Data analysis is proceeding according to the plan.
One potentially interesting finding is the identification of 9 genes encoding transcription factors belonging to doublesex-/mab-3-related group which are dynamically expressed during metamorphosis. Some of them are strictly polyp-specific and others are predominantly expressed in the jellyfish stage. In other animal models orthologs of these genes function as markers of developing germ cells (during embryogenesis and in gonads) and their high expression in the polyp stage (does not have gonads) is unusual. Due to the immortal nature of Aurelia polyp stage this finding might be interesting. One possible explanation might be that in Aurelia the activation of mab-3-related transcription factors contributes to the maintenance of unlimited proliferation potential of epithelial cells of the polyp stage. In essence it means that at least some part of polyp tissues might be kept in the state close to that in embryonic cells of higher animals.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Project proceeds according to the research plan because the technology for mRNA extraction, RNAseq sequencing and data analysis were tested by PI on Aurelia previously. Next steps such as ChIPseq might be more technically challenging. So far no technical difficulties were encounted.
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| Strategy for Future Research Activity |
I plan to follow the research scheme originally proposed in the application.
So far there is no need for any adjustment of research plan.
In FY2018 I will generate genome-wide maps of histone modifications during
polyp-to-jellyfish transition by using antibodies against H3K4me3, H3K4me2, H3K4me1, H3K36me3, H3K27ac followed by chromatin immunoprecipitation and sequencing on Illumina platform. Resulting data will be mapped to the genome assembly and genes with differential histone modification patterns during polyp-to-jellyfish transition will be identified. After that it will be possible to check for correlation between histone modifications and the set of differentially regulated genes identifier during FY2017.
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| Causes of Carryover |
Transcriptomic sequencing for jellyfish stages (J1,J2) and strobila head (S1) were performed in duplicates which reduced the cost of consumables. Originally I planned to make all sequencing steps in triplicates. However, taking into consideration that we work with clonal cultures, two biological replicates per life stage seem to be sufficient. Remaining amount transferred from FY2017 will be used for additional sequencing in FY2018.
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