title: Transformation of the Cyanidioschyzon merolae chloroplast genome: prospects for understanding chloroplast function in extreme environments.
abstract: We have successfully transformed an exthemophilic red alga with the chloramphenicol acetyltransferase gene, rendering this organism insensitive to its toxicity. Our work paves the way to further work with this new modelorganism. Here we report the first successful attempt to achieve a stable, under selectable pressure, chloroplast transformation in Cyanidioschizon merolae-an extremophilic red alga of increasing importance as a new model organism. The following protocol takes advantage of a double homologous recombination phenomenon in the chloroplast, allowing to introduce an exogenous, selectable gene. For that purpose, we decided to use chloramphenicol acetyltransferase (CAT), as chloroplasts are particularly vulnerable to chloramphenicol lethal effects (Zienkiewicz et al. in Protoplasma, 2015, doi: 10.1007/s00709-015-0936-9 ). We adjusted two methods of DNA delivery: the PEG-mediated delivery and the biolistic bombardment based delivery, either of these methods work sufficiently with noticeable preference to the former. Application of a codon-optimized sequence of the cat gene and a single colony selection yielded C. merolae strains, capable of resisting up to 400 µg/mL of chloramphenicol. Our method opens new possibilities in production of site-directed mutants, recombinant proteins and exogenous protein overexpression in C. merolae-a new model organism.
authors: Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland. maximus@biol.uw.edu.pl.
authors: Maksymilian
authors: M
authors: Zienkiewicz
authors: Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland.
authors: Tomasz
authors: T
authors: Krupnik
authors: Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland.
authors: Anna
authors: A
authors: Drożak
authors: Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland.
authors: Anna
authors: A
authors: Golke
authors: Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland.
authors: Elżbieta
authors: E
authors: Romanowska
mesh_terms: D019470:Biolistics; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D002736:Chloroplasts / Q000235:genetics* / Q000502:physiology; D054628:Genome, Chloroplast; D059765:Homologous Recombination; D030821:Plants, Genetically Modified; D000461:Rhodophyta / Q000235:genetics*; D014170:Transformation, Genetic
chemical_list: D015500:Chloramphenicol O-Acetyltransferase
keywords: Biolistic bombardment; Chloramphenicol acetyltransferase; Cyanidioschyzon merolae; PEG; Stable chloroplast transformation