Chapter 18
Efficient Transformation of the Diatoms Phaeodactylum
tricornutum by Multipulse Electroporation
Kentaro Ifuku and Dongyi Yan
Abstract
An efficient nuclear transformation method has been established for the pennate marine diatom Phaeodactylum tricornutum using an electroporation system that drives multisequence pulses to introduce foreign
DNAs into the cells. By removing excess salts in the culture medium and optimizing pulse conditions,
diatom cells can be transformed with high transformation efficiency. This method is also applicable to other
marine diatoms, such as the centric diatom Chaetoceros gracilis. This efficient and stable transformation
system will be useful for both functional analysis of diatom-specific genes and for further biotechnological
applications.
Key words Chaetoceros gracilis, Electroporation, Genetic transformation, Marine diatom, Multipulse,
Phaeodactylum tricornutum
1 Introduction
Diatoms are unicellular eukaryotic microalgae that play important
ecological roles on a global scale. Diatoms are responsible for 20%
of global carbon fixation and 40% of marine primary productivity
[1]. The evolutional history of diatoms as secondary endosymbionts also gives new insight into host–endosymbiont relationships
[2]. Furthermore, their unique abilities to form silica-based cell
walls and to produce valuable lipids have attracted attention to
them as biotechnologically important resources [3, 4]. For both
basic biological research and commercial exploitation of diatoms,
an efficient genetic transformation system is required. Transformation of diatoms has been reported for a number of diatom species,
where delivery of foreign DNAs into diatom cells has been mostly
done by a microprojectile bombardment [5–7]. However, this
method is not suited to high-throughput transformation of diatom
cells due to the time required for sample preparation, costly consumables, and limited transformation efficiency.
Shulin Li et al. (eds.), Electroporation Protocols: Microorganism, Mammalian System, and Nanodevice,
Methods in Molecular Biology, vol. 2050, https://doi.org/10.1007/978-1-4939-9740-4_18,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
169
Efficient Transformation of the Diatoms Phaeodactylum
tricornutum by Multipulse Electroporation
Kentaro Ifuku and Dongyi Yan
Abstract
An efficient nuclear transformation method has been established for the pennate marine diatom Phaeodactylum tricornutum using an electroporation system that drives multisequence pulses to introduce foreign
DNAs into the cells. By removing excess salts in the culture medium and optimizing pulse conditions,
diatom cells can be transformed with high transformation efficiency. This method is also applicable to other
marine diatoms, such as the centric diatom Chaetoceros gracilis. This efficient and stable transformation
system will be useful for both functional analysis of diatom-specific genes and for further biotechnological
applications.
Key words Chaetoceros gracilis, Electroporation, Genetic transformation, Marine diatom, Multipulse,
Phaeodactylum tricornutum
1 Introduction
Diatoms are unicellular eukaryotic microalgae that play important
ecological roles on a global scale. Diatoms are responsible for 20%
of global carbon fixation and 40% of marine primary productivity
[1]. The evolutional history of diatoms as secondary endosymbionts also gives new insight into host–endosymbiont relationships
[2]. Furthermore, their unique abilities to form silica-based cell
walls and to produce valuable lipids have attracted attention to
them as biotechnologically important resources [3, 4]. For both
basic biological research and commercial exploitation of diatoms,
an efficient genetic transformation system is required. Transformation of diatoms has been reported for a number of diatom species,
where delivery of foreign DNAs into diatom cells has been mostly
done by a microprojectile bombardment [5–7]. However, this
method is not suited to high-throughput transformation of diatom
cells due to the time required for sample preparation, costly consumables, and limited transformation efficiency.
Shulin Li et al. (eds.), Electroporation Protocols: Microorganism, Mammalian System, and Nanodevice,
Methods in Molecular Biology, vol. 2050, https://doi.org/10.1007/978-1-4939-9740-4_18,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
169