Toward establishing model organisms for marine protists: Successful transfection protocols for Parabodo caudatus (Kinetoplastida: Excavata)

Environ Microbiol. 2017 Sep;19(9):3487-3499. doi: 10.1111/1462-2920.13830. Epub 2017 Jul 21.

Abstract

We developed protocols for, and demonstrated successful transfection of, the free-living kinetoplastid flagellate Parabodo caudatus with three plasmids carrying a fluorescence reporter gene (pEF-GFP with the EF1 alpha promoter, pUB-GFP with Ubiquitin C promoter, and pEYFP-Mitotrap with CMV promoter). We evaluated three electroporation approaches: (1) a square-wave electroporator designed for eukaryotes, (2) a novel microfluidic transfection system employing hydrodynamically-controlled electric field waveforms, and (3) a traditional exponential decay electroporator. We found the microfluidic device provides a simple and efficient platform to quickly test a wide range of electric field parameters to find the optimal set of conditions for electroporation of target species. It also allows for processing large sample volumes (>10 ml) within minutes, increasing throughput 100 times over cuvettes. Fluorescence signal from the reporter gene was detected a few hours after transfection and persisted for 3 days in cells transfected by pEF-GFP and pUB-GFP plasmids and for at least 5 days post-transfection for cells transfected with pEYFP-Mitotrap. Expression of the reporter genes (GFP and YFP) was also confirmed using reverse transcription-PCR (RT-PCR). This work opens the door for further efforts with this taxon and close relatives toward establishing model systems for genome editing.

MeSH terms

  • Animals
  • Cell Survival / physiology
  • Electroporation / methods*
  • Genes, Reporter / genetics*
  • Green Fluorescent Proteins / genetics*
  • Kinetoplastida / genetics*
  • Kinetoplastida / physiology
  • Microfluidics / instrumentation
  • Microfluidics / methods
  • Plasmids / genetics*
  • Promoter Regions, Genetic / genetics
  • Transfection / methods*

Substances

  • Green Fluorescent Proteins