Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.

Chlamydomonas reinhardtii is an important model organism for the study of many cellular processes, and protein tagging is an increasingly indispensable tool for these studies. To circumvent the disadvantages of conventional approaches in creating a tagged cell line, which involve transforming either...

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Main Authors: Yuqing Hou, Xi Cheng, George B Witman
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0278972
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author Yuqing Hou
Xi Cheng
George B Witman
author_facet Yuqing Hou
Xi Cheng
George B Witman
author_sort Yuqing Hou
collection DOAJ
description Chlamydomonas reinhardtii is an important model organism for the study of many cellular processes, and protein tagging is an increasingly indispensable tool for these studies. To circumvent the disadvantages of conventional approaches in creating a tagged cell line, which involve transforming either a wild-type or null-mutant cell line with an exogenous DNA construct that inserts randomly into the genome, we developed a strategy to tag the endogenous gene in situ. The strategy utilizes TIM, a CRISPR/Cas9-based method for targeted insertional mutagenesis in C. reinhardtii. We have tested the strategy on two genes: LF5/CDKL5, lack of which causes a long-flagella phenotype, and Cre09.g416350/NAP1L1, which has not been studied previously in C. reinhardtii. We successfully tagged the C-terminus of wild-type LF5 with the hemagglutinin (HA) tag with an efficiency of 7.4%. Sequencing confirmed that these strains are correctly edited. Western blotting confirmed the expression of HA-tagged LF5, and immunofluorescence microscopy showed that LF5-HA is localized normally. These strains have normal length flagella and appear wild type. We successfully tagged the N-terminus of Cre09.g416350 with mNeonGreen-3xFLAG with an efficiency of 9%. Sequencing showed that the tag region in these strains is as expected. Western blotting confirmed the expression of tagged protein of the expected size in these strains, which appeared to have normal cell size, growth rate, and swimming speed. This is the first time that C. reinhardtii endogenous genes have been edited in situ to express a wild-type tagged protein. This effective, efficient, and convenient TIM-tagging strategy promises to be a useful tool for the study of nuclear genes, including essential genes, in C. reinhardtii.
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spelling doaj.art-1c79f0762f49404cb6b048f8d915d38f2023-01-14T05:31:39ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-011712e027897210.1371/journal.pone.0278972Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.Yuqing HouXi ChengGeorge B WitmanChlamydomonas reinhardtii is an important model organism for the study of many cellular processes, and protein tagging is an increasingly indispensable tool for these studies. To circumvent the disadvantages of conventional approaches in creating a tagged cell line, which involve transforming either a wild-type or null-mutant cell line with an exogenous DNA construct that inserts randomly into the genome, we developed a strategy to tag the endogenous gene in situ. The strategy utilizes TIM, a CRISPR/Cas9-based method for targeted insertional mutagenesis in C. reinhardtii. We have tested the strategy on two genes: LF5/CDKL5, lack of which causes a long-flagella phenotype, and Cre09.g416350/NAP1L1, which has not been studied previously in C. reinhardtii. We successfully tagged the C-terminus of wild-type LF5 with the hemagglutinin (HA) tag with an efficiency of 7.4%. Sequencing confirmed that these strains are correctly edited. Western blotting confirmed the expression of HA-tagged LF5, and immunofluorescence microscopy showed that LF5-HA is localized normally. These strains have normal length flagella and appear wild type. We successfully tagged the N-terminus of Cre09.g416350 with mNeonGreen-3xFLAG with an efficiency of 9%. Sequencing showed that the tag region in these strains is as expected. Western blotting confirmed the expression of tagged protein of the expected size in these strains, which appeared to have normal cell size, growth rate, and swimming speed. This is the first time that C. reinhardtii endogenous genes have been edited in situ to express a wild-type tagged protein. This effective, efficient, and convenient TIM-tagging strategy promises to be a useful tool for the study of nuclear genes, including essential genes, in C. reinhardtii.https://doi.org/10.1371/journal.pone.0278972
spellingShingle Yuqing Hou
Xi Cheng
George B Witman
Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.
PLoS ONE
title Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.
title_full Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.
title_fullStr Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.
title_full_unstemmed Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.
title_short Direct in situ protein tagging in Chlamydomonas reinhardtii utilizing TIM, a method for CRISPR/Cas9-based targeted insertional mutagenesis.
title_sort direct in situ protein tagging in chlamydomonas reinhardtii utilizing tim a method for crispr cas9 based targeted insertional mutagenesis
url https://doi.org/10.1371/journal.pone.0278972
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