Methodologies for transferring DNA into eukaryotic microalgae: a review

J.M Coll

doi:10.5424/sjar/2006044-209

Abstract

Agitation with glass beads, electroporation and microparticle bombardment are all used to transfer exogenous genes into unicellular eukaryotic algae (microalgae). For nuclear transformation most researchers use glass beads techniques or, to a lesser extent, electroporation, while for chloroplast transformation bombardment is often used. Glass bead agitation and electroporation require the removal of the cell wall while bombardment can be performed with intact microalgae. Chlamydomonas reinhardtii has been the microalga most commonly transformed, but success has also been reported with Volvox carteri, Chlorella spp., Dunaliella salina, Haematococcus pluvialis, Euglena gracilis, diatoms (Phaeodactylum tricornutum, Navicula saprophila, Cyclotella cryptica and Thalassiosira weissflogii), dinoflagellates (Amphidinium klebsii and Symbiodinium microadriaticum) and red algae (Porphyridium spp and Cyanidioschyzon merolae). The first C. reinhardtii transformants produced by making use of Agrobacterium tumefaciens have also been reported. A comparison of the above methods might help provide the information necessary to successfully transform further microalgal species.

Highlights

Unicellular eukaryotic algae stably expressing an exogenous gene have been obtained for basic research and for certain practical applications (Table 1)
To select the few transformants produced among the many transfected microalgae obtained by these methods, two procedures are possible: 1) the rescue of auxotrophic mutants, or 2) selection by resistance to antibiotics/herbicides
The presence of exogenous demonstrated in most reports by Southern (DNA) in the genomes of C. reinhardtii (Rochaix and VanDillewijn, 1982; Sizova et al, 1996) and Ch. ellipsoidea (Kim et al, 2002) transformants has been correlated with survival in the absence of selection (Table 3)

Summary

Introduction

Unicellular eukaryotic algae (referred to as microalgae in this review) stably expressing an exogenous gene have been obtained for basic research and for certain practical applications (Table 1). From ~ 1 to 100 transformants per million transfected microalgae have been obtained with C. reinhardtii, D. salina, Ch. vulgaris and Ch. ellipsoidea using the glass bead method (Table 3).

Results

Conclusion