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Watanabe Y, Kadono T, Kira N, Suzuki K, Iwata O, Ohnishi K, Yamaguchi H, Adachi M. Development of endogenous promoters that drive high-level expression of introduced genes in the model diatom Phaeodactylum tricornutum. Mar Genomics 2018; 42:41-48. [PMID: 30509379 DOI: 10.1016/j.margen.2018.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 06/20/2018] [Accepted: 06/20/2018] [Indexed: 10/28/2022]
Abstract
The marine diatom Phaeodactylum tricornutum is attractive for basic and applied diatom research. We isolated putative endogenous gene promoters derived from genes that are highly expressed in P. tricornutum: the fucoxanthin chlorophyll a/c-binding protein (FCP) C gene, the vacuolar ATP synthase 16-kDa proteolipid subunit (V-ATPase C) gene, the clumping factor A gene and the solute carrier family 34 member 2 gene. Five putative promoter regions were isolated, linked to an antibiotic resistance gene (Sh ble) and transformed into P. tricornutum. Using quantitative RT-PCR, the promoter activities in the transformants were analyzed and compared to that of the diatom endogenous gene promoter, the FCP A gene promoter which has been used for the transformation of P. tricornutum. Among the five isolated potential promoters, the activity of the V-ATPase C gene promoter was approximately 2.73 times higher than that of the FCP A gene promoter. The V-ATPase C gene promoter drove the expression of Sh ble mRNA transcripts under both light and dark conditions at the stationary phase. These results suggest that the V-ATPase C gene promoter is a novel tool for the genetic engineering of P. tricornutum.
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Affiliation(s)
- Yumi Watanabe
- Laboratory of Aquatic Environmental Science, Faculty of Agriculture and Marine Science, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan
| | - Takashi Kadono
- Laboratory of Aquatic Environmental Science, Faculty of Agriculture and Marine Science, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan
| | - Nozomu Kira
- Laboratory of Aquatic Environmental Science, Faculty of Agriculture and Marine Science, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan
| | - Kengo Suzuki
- Euglena Co., Ltd., 22F, Morinaga Plaza Building, Shiba-5-33-1, Minato-ku, Tokyo 108-0019, Japan
| | - Osamu Iwata
- Euglena Co., Ltd., 22F, Morinaga Plaza Building, Shiba-5-33-1, Minato-ku, Tokyo 108-0019, Japan
| | - Kouhei Ohnishi
- Research Institute of Molecular Genetics, Kochi University, Otsu-200, Nankoku, Kochi 783-8502, Japan
| | - Haruo Yamaguchi
- Laboratory of Aquatic Environmental Science, Faculty of Agriculture and Marine Science, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan
| | - Masao Adachi
- Laboratory of Aquatic Environmental Science, Faculty of Agriculture and Marine Science, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan.
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Ferriols VMEN, Yaginuma-Suzuki R, Fukunaga K, Kadono T, Adachi M, Matsunaga S, Okada S. An exception among diatoms: unique organization of genes involved in isoprenoid biosynthesis in Rhizosolenia setigera CCMP 1694. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:822-833. [PMID: 28921701 DOI: 10.1111/tpj.13719] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/27/2017] [Accepted: 09/04/2017] [Indexed: 06/07/2023]
Abstract
The marine diatom Rhizosolenia setigera is unique among this group of microalgae given that it is only one of a handful of diatom species that can produce highly branched isoprenoid (HBI) hydrocarbons. In our efforts to determine distinguishing molecular characteristics in R. setigera CCMP 1694 that could help elucidate the underlying mechanisms for its ability to biosynthesize HBIs, we discovered the occurrence of independent genes encoding for two isopentenyl diphosphate isomerases (RsIDI1 and RsIDI2) and one squalene synthase (RsSQS), enzymes that catalyze non-consecutive steps in isoprenoid biosynthesis. These genes are peculiarly fused in all other genome-sequenced diatoms to date, making their organization in R. setigera CCMP 1694 a clear distinguishing molecular feature. Phylogenetic and sequence analysis of RsIDI1, RsIDI2, and RsSQS revealed that such an arrangement of individually transcribed genes involved in isoprenoid biosynthesis could have arisen through a secondary gene fission event. We further demonstrate that inhibition of squalene synthase (SQS) shifts the flux of exogenous isoprenoid precursors towards HBI biosynthesis suggesting the competition for isoprenoid substrates in the form of farnesyl diphosphate between the sterol and HBI biosynthetic pathways in this diatom.
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Affiliation(s)
- Victor Marco Emmanuel N Ferriols
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Institute of Aquaculture, University of the Philippines Visayas, Iloilo, Philippines
| | - Ryoko Yaginuma-Suzuki
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | | | | | - Masao Adachi
- Faculty of Agriculture, Kochi University, Kochi, Japan
| | - Shigeki Matsunaga
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Shigeru Okada
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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