This work was supported by Shenzhen Science and Technology Program (Grant No. KQTD20180411143628272) and special funds for science technology innovation and industrial development of Shenzhen Dapeng New District (Grant No. PT202101-02).

1. Target design and in vitro synthesis of sgRNA
<ol>
	<li>Predict the structure of target genes of interest and determine the boundaries between exons and introns via bioinformatic analysis of the B. dorsalis genome (software applications used here are listed in the Table of Materials). 
	NOTE: BLAT20 was used to search potential gene loci in the genome. The high-quality RNA-seq reads (transcriptome) were aligned to the acquired...

<ol>
	<li>Christenson, L. D., Foote, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biology+of+fruit+flies.">Biology of fruit flies.</a> Annual Review of Entomology. 5 (1), 171-192 (1960).</li><li>Ma, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+assessment+of+the+economic+losses+caused+by+Bactrocera+dorsalis,+B.+cucurbitae+and+B.+tau+to+Guangdong+province.">The assessment of the economic losses caused by Bactrocera dorsalis, B. cucurbitae and B. tau to Guangdong province.</a> Plant Quarantine. 27 (3), 50-56 (2013).</li><li>Jin, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+control+measures+and+drug+resistance+management+of+Bactrocera+dorsalis.">Chemical control measures and drug resistance management of Bactrocera dorsalis.</a> Agrochemicals. 60 (1), 1-5 (2021).</li><li>Yang, B., Liu, Y., Wang, B., Wang, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Olfaction-based+behaviorally+manipulated+technology+of+pest+insects:+research+progress,+opportunities+and+challenges.">Olfaction-based behaviorally manipulated technology of pest insects: research progress, opportunities and challenges.</a> Bulletin of National Natural Science Foundation of China. 34 (4), 441-446 (2020).</li><li>Jinek, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+programmable+dual-RNA-guided+DNA+endonuclease+in+adaptive+bacterial+immunity.">A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity.</a> Science. 337 (6096), 816-821 (2012).</li><li>Garneau, J. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+CRISPR/Cas+bacterial+immune+system+cleaves+bacteriophage+and+plasmid+DNA.">The CRISPR/Cas bacterial immune system cleaves bacteriophage and plasmid DNA.</a> Nature. 468 (7320), 67-71 (2010).</li><li>Pyzocha, N. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA-guided+genome+editing+of+mammalian+cells.">RNA-guided genome editing of mammalian cells.</a> Gene Correction. , 269-277 (2014).</li><li>Weiss, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CRISPR-Cas+systems:+new+players+in+gene+regulation+and+bacterial+physiology.">CRISPR-Cas systems: new players in gene regulation and bacterial physiology.</a> Frontiers in Cellular and Infection Microbiology. 4, 37 (2014).</li><li>Doudna, J. A., Charpentier, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+new+frontier+of+genome+engineering+with+CRISPR-Cas9.">The new frontier of genome engineering with CRISPR-Cas9.</a> Science. 346 (6213), 1258096 (2014).</li><li>Cong, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiplex+genome+engineering+using+CRISPR/Cas+systems.">Multiplex genome engineering using CRISPR/Cas systems.</a> Science. 339 (6121), 819-823 (2013).</li><li>Li, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heritable+gene+targeting+in+the+mouse+and+rat+using+a+CRISPR-Cas+system.">Heritable gene targeting in the mouse and rat using a CRISPR-Cas system.</a> Nature Biotechnology. 31 (8), 681-683 (2013).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-step+generation+of+mice+carrying+mutations+in+multiple+genes+by+CRISPR/Cas-mediated+genome+engineering.">One-step generation of mice carrying mutations in multiple genes by CRISPR/Cas-mediated genome engineering.</a> Cell. 153 (4), 910-918 (2013).</li><li>Li, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generating+mutant+Aedes+aegypti+mosquitoes+using+the+CRISPR/Cas9+system.">Generating mutant Aedes aegypti mosquitoes using the CRISPR/Cas9 system.</a> STAR protocols. 2 (2), 100432 (2021).</li><li>Zhu, G. -. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expanding+the+toolkit+for+genome+editing+in+a+disease+vector,+Aedes+aegypti:+transgenic+lines+expressing+Cas9+and+single+guide+RNA+induce+efficient+mutagenesis.">Expanding the toolkit for genome editing in a disease vector, Aedes aegypti: transgenic lines expressing Cas9 and single guide RNA induce efficient mutagenesis.</a> The CRISPR Journal. 4 (6), 846-853 (2021).</li><li>Li, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CRISPR/Cas9+in+locusts:+Successful+establishment+of+an+olfactory+deficiency+line+by+targeting+the+mutagenesis+of+an+odorant+receptor+co-receptor+(Orco).">CRISPR/Cas9 in locusts: Successful establishment of an olfactory deficiency line by targeting the mutagenesis of an odorant receptor co-receptor (Orco).</a> Insect Biochemistry and Molecular Biology. 79, 27-35 (2016).</li><li>Liu, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deletion+of+the+Bombyx+mori+odorant+receptor+co-receptor+(BmOrco)+impairs+olfactory+sensitivity+in+silkworms.">Deletion of the Bombyx mori odorant receptor co-receptor (BmOrco) impairs olfactory sensitivity in silkworms.</a> Insect Biochemistry &amp; Molecular Biology. 86, 58-67 (2017).</li><li>Zhao, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+somatic+and+germline+genome+engineering+of+Bactrocera+dorsalis+by+the+CRISPR/Cas9+system.">Efficient somatic and germline genome engineering of Bactrocera dorsalis by the CRISPR/Cas9 system.</a> Pest Management Science. 75 (7), 1921-1932 (2019).</li><li>Bai, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CRISPR/Cas9-mediated+knockout+of+the+eye+pigmentation+gene+white+leads+to+alterations+in+colour+of+head+spots+in+the+oriental+fruit+fly,+Bactrocera+dorsalis.">CRISPR/Cas9-mediated knockout of the eye pigmentation gene white leads to alterations in colour of head spots in the oriental fruit fly, Bactrocera dorsalis.</a> Insect Molecular Biology. 28 (6), 837-849 (2019).</li><li>Zheng, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clustered+regularly+interspaced+short+palindromic+repeats+(CRISPR)/CRISPR-associated+9-mediated+mutagenesis+of+the+multiple+edematous+wings+gene+induces+muscle+weakness+and+flightlessness+in+Bactrocera+dorsalis+(Diptera:+Tephritidae).">Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9-mediated mutagenesis of the multiple edematous wings gene induces muscle weakness and flightlessness in Bactrocera dorsalis (Diptera: Tephritidae).</a> Insect Molecular Biology. 28 (2), 222-234 (2019).</li><li>Kent, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BLAT-the+BLAST-like+alignment+tool.">BLAT-the BLAST-like alignment tool.</a> Genome Research. 12 (4), 656-664 (2002).</li><li>Kim, D., Langmead, B., Salzberg, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HISAT:+A+fast+spliced+aligner+with+low+memory+requirements.">HISAT: A fast spliced aligner with low memory requirements.</a> Nature Methods. 12 (4), 357-360 (2015).</li><li>Danecek, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twelve+years+of+SAMtools+and+BCFtools.">Twelve years of SAMtools and BCFtools.</a> Gigascience. 10 (2), (2021).</li><li>Kovaka, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptome+assembly+from+long-read+RNA-seq+alignments+with+StringTie2.">Transcriptome assembly from long-read RNA-seq alignments with StringTie2.</a> Genome Biology. 20 (1), 278 (2019).</li><li>. TransDecoder Available from: <a target="_blank" href="https://github.com/TransDecoder/TransDecoder/releases/tag/TransDecoder-v5.5.0">https://github.com/TransDecoder/TransDecoder/releases/tag/TransDecoder-v5.5.0</a> (2018)</li><li>Robinson, J. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrative+genomics+viewer.">Integrative genomics viewer.</a> Nature Biotechnology. 29 (1), 24-26 (2011).</li><li>Chang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+pheromone+antagonist+regulates+optimal+mating+time+in+the+moth+Helicoverpa+armigera.">A pheromone antagonist regulates optimal mating time in the moth Helicoverpa armigera.</a> Current Biology. 27 (11), 1610-1615 (2017).</li><li>Xie, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=sgRNAcas9:+a+software+package+for+designing+CRISPR+sgRNA+and+evaluating+potential+off-target+cleavage+sites.">sgRNAcas9: a software package for designing CRISPR sgRNA and evaluating potential off-target cleavage sites.</a> PloS One. 9 (6), 100448 (2014).</li><li>Zheng, Q. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Precise+gene+deletion+and+replacement+using+the+CRISPR/Cas9+system+in+human+cells.">Precise gene deletion and replacement using the CRISPR/Cas9 system in human cells.</a> Biotechniques. 57 (3), 115-124 (2014).</li><li>Ren, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rectal+bacteria+produce+sex+pheromones+in+the+male+oriental+fruit+fly.">Rectal bacteria produce sex pheromones in the male oriental fruit fly.</a> Current Biology. 31 (10), 2220-2226 (2021).</li><li>Xiao, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+CRISPR/Cas9-based+gene+editing+in+HIV-1/AIDS+therapy.">Application of CRISPR/Cas9-based gene editing in HIV-1/AIDS therapy.</a> Frontiers in Cellular and Infection Microbiology. 9, 69 (2019).</li><li>El-Mounadi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Principles,+applications,+and+biosafety+of+plant+genome+editing+using+CRISPR-Cas9.">Principles, applications, and biosafety of plant genome editing using CRISPR-Cas9.</a> Frontiers in Plant Science. 11, 56 (2020).</li><li>Hsu, P. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+applications+of+CRISPR-Cas9+for+genome+engineering.">Development and applications of CRISPR-Cas9 for genome engineering.</a> Cell. 157 (6), 1262-1278 (2014).</li><li>Labun, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CHOPCHOP+v3:+expanding+the+CRISPR+web+toolbox+beyond+genome+editing.">CHOPCHOP v3: expanding the CRISPR web toolbox beyond genome editing.</a> Nucleic Acids Research. 47, 171-174 (2019).</li><li>Ai, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryo+microinjection+and+knockout+mutant+identification+of+CRISPR/Cas9+genome-edited+Helicoverpa+armigera+(H&#252;bner).">Embryo microinjection and knockout mutant identification of CRISPR/Cas9 genome-edited Helicoverpa armigera (H&#252;bner).</a> Journal of Visualized Experiments. (173), e62068 (2021).</li><li>Xie, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=sgRNAcas9:+a+software+package+for+designing+CRISPR+sgRNA+and+evaluating+potential+off-target+cleavage+sites.">sgRNAcas9: a software package for designing CRISPR sgRNA and evaluating potential off-target cleavage sites.</a> PloS One. 9 (6), 100448 (2014).</li><li>Gratz, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome+engineering+of+Drosophila+with+the+CRISPR+RNA-guided+Cas9+nuclease.">Genome engineering of Drosophila with the CRISPR RNA-guided Cas9 nuclease.</a> Genetics. 194 (4), 1029-1035 (2013).</li><li>Zhu, G. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Knockout+of+juvenile+hormone+receptor,+Methoprene-tolerant,+induces+black+larval+phenotype+in+the+yellow+fever+mosquito,+Aedes+aegypti.">Knockout of juvenile hormone receptor, Methoprene-tolerant, induces black larval phenotype in the yellow fever mosquito, Aedes aegypti.</a> Proceedings of the National Academy of Sciences. 116 (43), 21501-21507 (2019).</li><li>Laohakieat, K., Isasawin, S., Thanaphum, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+transformer-2+and+fruitless+characterisation+with+developmental+expression+profiles+of+sex-determining+genes+in+Bactrocera+dorsalis+and+B.+correcta.">The transformer-2 and fruitless characterisation with developmental expression profiles of sex-determining genes in Bactrocera dorsalis and B. correcta.</a> Scientific Reports. 10 (1), 1-13 (2020).</li><li>Gabrieli, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sperm-less+males+modulate+female+behaviour+in+Ceratitis+capitata+(Diptera:+Tephritidae).">Sperm-less males modulate female behaviour in Ceratitis capitata (Diptera: Tephritidae).</a> Insect Biochemistry and Molecular Biology. 79, 13-26 (2016).</li></ol>

The CRISPR/Cas9 system is the most widely used gene editing tool and has various applications, such as gene threpy30, crop breeding31, and basic studies of gene fuctions32. This system has already been applied for gene editing in various insect species and has served as an effective tool for functional gene studies in pests. The protocols we present here standardize the procedure of design and synthesis of guide RNAs, collecting embryos, embryo injec...

The Oriental fruit fly, Bactrocera dorsalis, is a cosmopolitan insect pest species that causes damage to over 150 species of fruit crops, including guava, mango, Eugenia spp., Surinam cherry, citrus, loquat, and papaya1. The damage caused in Guangdong Province (China) alone is estimated at over 200 million yuans. Adult females insert their eggs beneath the skin of ripening or ripened fruits, causing decay and abscission of the fruit, which decreases fruit quality and overall yield of the crop2. Since adult fruit flies have great flight capacity and their larvae bore into the fruit skin, insecticides requiring direct contact with the pest perform poorly in the field. Additionally, the extensive use of insecticides has increased the resistance of B. dorsalis against various agricultural chemicals, making control of these damaging pests even more difficult3. Therefore, the development of effective and environmentally friendly pest management strategies is desperately needed.
Recently, with the development of molecular biological tools and high-throughput sequencing technologies, scientists are attempting to develop environmentally-friendly pest management strategies, such as RNAi, that target the functionality of important genes (molecular targets) of various insect pests. Genes that are critical to the survival and reproduction of the pest can be identified through functional gene studies and further serve as potential molecular targets for the improvement of specifically targeted and environmentally friendly pest management tools4. To adapt such strategies to Oriental fruit fly control, effective methods for functional gene research are needed.
The CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) endonuclease system was initially discovered in bacteria and archaea and found to be an adaptive mechanism involved in the recognition and degradation of foreign intracellular DNA, such as that introduced by infecting bacteriophages5. In the type II CRISPR system, Cas9 endonuclease is guided by small associated RNAs (crRNA and tracrRNA) to cleave trespassing DNA6,7,8 and has become one of the most widely used tools for gene-editing to date9,10,11,12. Since the CRISPR/Cas9 system has several advantages, such as high efficiency of gene silencing and low cost, it has already been applied for gene editing in various insect species, including Aedes aegypti13,14, Locusta migratoria15, and Bombyx mori16. In B. dorsalis, genes related to body color, wing dimorphism, and sex determination have been successfully knocked out using CRISPR/Cas917,18,19. However, detailed procedures for CRISPR/Cas9 application in this insect remain incomplete. Moreover, some steps provided by researchers for B. dorsalis gene editing are also varied and in need of standardization. For example, the forms of Cas9 were different in published references17,18,19.
This paper provides a systematic method for mutagenesis of B. dorsalis using the CRISPR/Cas9 system, including the design and synthesis of guide RNAs, collecting embryos, embryo injection, insect rearing, and mutant screening. This protocol will serve as a useful guide for generating mutant flies for researchers who are interested in the functional gene studies in B. dorsalis.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>6x DNA Loading Buffer</td>
			<td>TransGen Biotech</td>
			<td>GH101-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Artificial climate chamber</td>
			<td>ShangHai BluePard</td>
			<td>MGC-350P</td>
			<td></td>
		</tr>
		<tr>
			<td>AxyPrep Genomic DNA Mini-Extraction Kit</td>
			<td>Axygen</td>
			<td>AP-MN-MS-GDNA-250G</td>
			<td></td>
		</tr>
		<tr>
			<td>BLAT</td>
			<td>NA</td>
			<td>NA</td>
			<td>For searching potential gene loci in the genome</td>
		</tr>
		<tr>
			<td>Capillary Glass</td>
			<td>WPI&#160;</td>
			<td>1B100F-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf InjectMan 4 micromanipulator</td>
			<td>Eppendorf</td>
			<td>InjectMan 4</td>
			<td></td>
		</tr>
		<tr>
			<td>GeneArt Precision gRNA Synthesis Kit</td>
			<td>Thermo Fisher Scientific</td>
			<td>A29377</td>
			<td></td>
		</tr>
		<tr>
			<td>Hisat2</td>
			<td>NA</td>
			<td>NA</td>
			<td>For aligning the transcriptome to the acquired gene loci</td>
		</tr>
		<tr>
			<td>IGV</td>
			<td>NA</td>
			<td>NA</td>
			<td>For visualizing the results from Transdecoder</td>
		</tr>
		<tr>
			<td>Microgrinder</td>
			<td>NARISHIGE</td>
			<td>EG-401</td>
			<td></td>
		</tr>
		<tr>
			<td>Olympus Microscope</td>
			<td>Olympus Corporation</td>
			<td>SZ2-ILST</td>
			<td></td>
		</tr>
		<tr>
			<td>pEASY-Blunt Cloning Kit</td>
			<td>TransGen Biotech</td>
			<td>CB101-02</td>
			<td>https://www.transgenbiotech.com/data/upload/pdf/CB101_2022-07-14.pdf</td>
		</tr>
		<tr>
			<td>Phenol red solution</td>
			<td>Sigma-Aldrich</td>
			<td>P0290-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette cookbook 2018 P-97 &#38; P-1000 Micropipette Pullers</td>
			<td>Instrument Company&#160;</td>
			<td></td>
			<td>https://www.sutter.com/PDFs/cookbook.pdf</td>
		</tr>
		<tr>
			<td>PrimeSTAR HS (Premix)</td>
			<td>Takara Biomedical Technology</td>
			<td>R040A</td>
			<td></td>
		</tr>
		<tr>
			<td>SAMtools</td>
			<td>NA</td>
			<td>NA</td>
			<td>For generating the sorted bam files</td>
		</tr>
		<tr>
			<td>sgRNAcas9-AI</td>
			<td>NA</td>
			<td>NA</td>
			<td>sgRNA design 
			http://123.57.239.141:8080/home</td>
		</tr>
		<tr>
			<td>Sutter Micropipette Puller Sutter&#160;</td>
			<td>Instrument Company&#160;</td>
			<td>P-97</td>
			<td></td>
		</tr>
		<tr>
			<td>Trans2K DNA Marker</td>
			<td>TransGen Biotech</td>
			<td>BM101-02</td>
			<td></td>
		</tr>
		<tr>
			<td>Transdecoder</td>
			<td>NA</td>
			<td>NA</td>
			<td>For combining the results of assemble transcripts and gene loci information 
			https://github.com/TransDecoder/TransDecoder/releases/tag/TransDecoder-v5.5.0</td>
		</tr>
		<tr>
			<td>TrueCut Cas9 Protein v2</td>
			<td>Thermo Fisher Scientific</td>
			<td>A36498</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultra-trace biological detector</td>
			<td>Thermo Fisher Scientific</td>
			<td>Nanodrop 2000C</td>
			<td></td>
		</tr>
	</tbody>
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protocols for crispr/cas9 mutagenesis of the oriental fruit fly bactrocera dorsalis

The Oriental fruit fly, Bactrocera dorsalis, is a highly invasive and adaptive pest species that causes damage to citrus and over 150 other fruit crops worldwide. Since adult fruit flies have great flight capacity and females lay their eggs under the skins of fruit, insecticides requiring direct contact with the pest usually perform poorly in the field. With the development of molecular biological tools and high-throughput sequencing technology, many scientists are attempting to develop environmentally friendly pest management strategies. These include RNAi or gene editing-based pesticides that downregulate or silence genes (molecular targets), such as olfactory genes involved in searching behavior, in various insect pests. To adapt these strategies for Oriental fruit fly control, effective methods for functional gene research are needed. Genes with critical functions in the survival and reproduction of B. dorsalis serve as good molecular targets for gene knockdown and/or silencing. The CRISPR/Cas9 system is a reliable technique used for gene editing, especially in insects. This paper presents a systematic method for CRISPR/Cas9 mutagenesis of B. dorsalis, including the design and synthesis of guide RNAs, collecting embryos, embryo injection, insect rearing, and mutant screening. These protocols will serve as a useful guide for generating mutant flies for researchers interested in functional gene studies in B. dorsalis.

This protocol presents detailed steps for the development of B. dorsalis mutants using CRISPR/Cas9 technology, including representative results from gDNA selection, collecting embryos and microinjection, insect maintenance, and mutant screening.
The example of the target site of the selected gene is located in the third exon (Figure 1C). This site is highly conserved, and a single band was detected by gel electrophoresis for the DNA template for synthetic...

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Protocols for CRISPR/Cas9 Mutagenesis of the Oriental Fruit Fly Bactrocera dorsalis

This paper presents the step-by-step protocols for CRISPR/Cas9 mutagenesis of the Oriental fruit fly Bactrocera dorsalis. Detailed steps provided by this standardized protocol will serve as a useful guide for generating mutant flies for functional gene studies in B. dorsalis.

Protocols for CRISPR/Cas9 Mutagenesis of the Oriental Fruit Fly Bactrocera dorsalis

The Oriental fruit fly, Bactrocera dorsalis, is a highly invasive and adaptive pest species that causes damage to citrus and over 150 other fruit crops ...

The oriental fruit fly is a highly invasive and adaptive pest species. Effective methods for functional gene research could help us to develop environmental-friendly pest management strategies. This method is high efficiency and low cost.Our protocol will serve as a useful guide for generating mutant flies for oriental fruit fly researchers. To begin, predict the structure of target genes of interest and determine the boundaries between exons and introns via bioinformatic analysis of the Bactroceras dorsalis genome. Use the commercially available gRNA synthesis kit to generate the designed sgRNA.Resuspend the gRNA product in nuclease-free water. Quantify the concentration using a UV-visible spectrophotometer and store at 80 degrees Celsius prior to use. Place B.dorsalis pupae into a plastic cage, with a rearing condition of 55%relative humidity, 26.5 degrees Celsius, and a 14:10 light/day cycle.When the adults eclose, provide a mixture of sugar and yeast as food along with water. Most adults reach sexual maturity 10 days after emergence. Use a light stand with a light of 30 to 50 lux to improve the fecundity of females, therefore, improving the efficiency of embryo collection.Next, place a 200-mesh gauze in the oviposition chamber, approximately 1 to 2 millimeters away from the chamber lid. Put a new oviposition chamber into the cage when the microinjection setup is ready. Collect the embryos every 10 minutes using a fine wet brush and line them up on a self-made injection plate.Dip the embryos into halocarbon oil during injection to avoid further desiccation. Prepare the working solution by mixing the Cas9 protein and the corresponding sgRNA to a concentration of 300 nanograms per microliters of each. Then, add 1 microliter of phenol red to the mixture to serve as a convenient way to mark injected embryos.Place the prepared mixture on ice to avoid degradation of the sgRNA. Prepare the glass injection needle using a micropipette puller. Add 3 microliters of the mixture into the injection needle without introducing air bubbles.Then, open the needle using a Microgrinder and connect it to the micromanipulator according to the user guide. Set the parameters for the injector as Pi to 500 hectopascals. Ti to 0.5 seconds, and PC to 200 hectopascals.Place the plate with lined-up embryos on the objective table. Then, adjust the micropipette position under a fine optical microscope, setting the micropipette and embryo on the same plane. Insert the needle tip into the posterior, or vegetal pole, of the embryo.Then, press the pedal from the injector to deliver the mixtures into the embryo. The appearance of slight reddish color is due to the addition of phenol red in the mixture. Place the injection plate with the injected embryos into an artificial climate chamber.After 36 hours, transfer the hatched larvae into larval diet using a fine-tip brush. Collect the larvae three or four times daily until no more larvae hatch. Next, place the mature larvae into the wet sand to pupate.The pupation stage takes 10 days. After pupation, move the pupae to a plastic cage before eclosion begins. After isolating genomic DNA from a fresh puparium or a single mid-leg of individual adults and designing the specific primers to amplify the target area, perform polymerase chain reaction, or PCR, following cycling conditions described in the text manuscript.Then, sequence the purified PCR products. Detecting multiple overlapping peaks adjacent to the target site suggests successful mutagenesis. For sub-cloning, mix the purified PCR products with a blunt-end vector and ligate them at 25 degrees Celsius for 15 minutes.Then, add trans-T1 cells and place it on ice for 30 minutes. Then, add 500 microliters of LB medium and incubate at 37 degrees Celsius for 1 hour with shaking. Centrifuge and discard the supernatant.Resuspend the pellet and spread it on an LB plate. Place the plate for overnight incubation at 37 degrees Celsius. Then, select individual bacterial colonies for sequencing to verify the genotype of the mutants.In this study, the example of the target site of the selected gene is located in the third exon. The target site is highly conserved, and a single band was detected by gel electrophoresis for the DNA template for synthetic gRNA and gRNA obtained in vitro transcription. B.dorsalis survival and mutagenesis after microinjections are shown here.After sequencing the PCR products, 80%of the G0 individuals are mosaic mutants. In mutant screening, the mutant with 8-base-pair deletion resulted in premature termination of amino acid translation. Inserting the needle into the posterior area or vegetal pole of an embryo is a central step because this directly affects the survival of eggs.This technological provides a reference for studying areas of gene functions in B.Dorsalis They can quickly capture the mutants they want through this method.

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2.1K ビュー.  Northeast Forestry University. オリエンタルショウジョウバエは、非常に侵襲的で適応性のある害虫種です。機能遺伝子研究のための効果的な方法は、環境にやさしい害虫管理戦略の開発に役立つ可能性があります。この方法は高効率かつ低コストである。私たちのプロトコルは、オリエンタルショウジョウバエ研究者にとって突然変異ハエを生成するための有用なガイドとして役立ちます。ま?...

ビデオ: Protocols for CRISPR/Cas9 Mutagenesis of the Oriental Fruit Fly Bactrocera dorsalis

Mutagenesis and Functional Selection Protocols for Directed Evolution of Proteins in E. coli

The efficient generation of genetic diversity represents an invaluable molecular tool that can be used to label DNA synthesis, to create unique molecular signatures, or to evolve proteins in the laboratory. Here, we present a protocol that allows the generation of large (>1011) mutant libraries for a given target sequence. This method is based on replication of a ColE1 plasmid encoding the desired sequence by a low-fidelity variant of DNA polymerase I (LF-Pol I). The target plasmid is transformed into a mutator strain of E. coli and plated on solid media, yielding between 0.2 and 1 mutations/kb, depending on the location of the target gene. Higher mutation frequencies are achieved by iterating this process of mutagenesis. Compared to alternative methods of mutagenesis, our protocol stands out for its simplicity, as no cloning or PCR are involved. Thus, our method is ideal for mutational labeling of plasmids or other Pol I templates or to explore large sections of sequence space for the evolution of activities not present in the original target. The tight spatial control that PCR or randomized oligonucleotide-based methods offer can also be achieved through subsequent cloning of specific sections of the library. Here we provide protocols showing how to create a random mutant library and how to establish drug-based selections in E. coli to identify mutants exhibiting new biochemical activities.

Mutagenesis and Functional Selection Protocols for Directed Evolution of Proteins in E. coli

Here we demonstrate a simple protocol to create a random mutant library for a given target sequence. We show how this method, which is performed in vivo in Escherichia coli, can be coupled with functional selections to evolve new enzymatic activities.

The efficient generation of genetic diversity represents an invaluable molecular tool that can be used to label DNA synthesis, to create unique molecular ...

Isolation and Biophysical Study of Fruit Cuticles

The cuticle, a hydrophobic protective layer on the aerial parts of terrestrial plants, functions as a versatile defensive barrier to various biotic and abiotic stresses and also regulates water flow from the external environment.1 A biopolyester (cutin) and long-chain fatty acids (waxes) form the principal structural framework of the cuticle; the functional integrity of the cuticular layer depends on the outer 'epicuticular' layer as well as the blend consisting of the cutin biopolymer and 'intracuticular' waxes.2 Herein, we describe a comprehensive protocol to extract waxes exhaustively from commercial tomato (Solanum lycopersicum) fruit cuticles or to remove epicuticular and intracuticular waxes sequentially and selectively from the cuticle composite. The method of Jetter and Sch&auml;ffer (2001) was adapted for the stepwise extraction of epicuticular and intracuticular waxes from the fruit cuticle.3,4 To monitor the process of sequential wax removal, solid-state cross-polarization magic-angle-spinning (CPMAS) 13C NMR spectroscopy was used in parallel with atomic force microscopy (AFM), providing molecular-level structural profiles of the bulk materials complemented by information on the microscale topography and roughness of the cuticular surfaces. To evaluate the cross-linking capabilities of dewaxed cuticles from cultivated wild-type and single-gene mutant tomato fruits, MAS 13C NMR was used to compare the relative proportions of oxygenated aliphatic (CHO and CH2O) chemical moieties.
Exhaustive dewaxing by stepwise Soxhlet extraction with a panel of solvents of varying polarity provides an effective means to isolate wax moieties based on the hydrophobic characteristics of their aliphatic and aromatic constituents, while preserving the chemical structure of the cutin biopolyester. The mechanical extraction of epicuticular waxes and selective removal of intracuticular waxes, when monitored by complementary physical methodologies, provides an unprecedented means to investigate the cuticle assembly: this approach reveals the supramolecular organization and structural integration of various types of waxes, the architecture of the cutin-wax matrix, and the chemical composition of each constituent. In addition, solid-state 13C NMR reveals differences in the relative numbers of CHO and CH2O chemical moieties for wild-type and mutant red ripe tomato fruits. The NMR techniques offer exceptional tools to fingerprint the molecular structure of cuticular materials that are insoluble, amorphous, and chemically heterogeneous. As a noninvasive surface-selective imaging technique, AFM furnishes an effective and direct means to probe the structural organization of the cuticular assembly on the nm-&mu;m length scale.

Aerial plant organs are protected by the cuticle, a supramolecular biopolyester-wax assembly. We present protocols to monitor selective removal of epi- and intracuticular waxes from tomato fruit cuticles on molecular and micro scales by solid-state NMR and atomic force microscopy, respectively, and to assess the cross-linking capacity of engineered cuticular biopolyesters.

The cuticle, a hydrophobic protective layer on the aerial parts of terrestrial plants, functions as a versatile defensive barrier to various biotic and ...

Generation of Genomic Deletions in Mammalian Cell Lines via CRISPR/Cas9

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific eukaryotic genome engineering. CRISPR/Cas9 is an inexpensive, facile, and efficient genome editing tool that allows genetic perturbation of genes and genetic elements. Here we present a simple methodology for CRISPR design, cloning, and delivery for the production of genomic deletions. In addition, we describe techniques for deletion, identification, and characterization. This strategy relies on cellular delivery of a pair of chimeric single guide RNAs (sgRNAs) to create two double strand breaks (DSBs) at a locus in order to delete the intervening DNA segment by non-homologous end joining (NHEJ) repair. Deletions have potential advantages as compared to single-site small indels given the efficiency of biallelic modification, ease of rapid identification by PCR, predictability of loss-of-function, and utility for the study of non-coding elements. This approach can be used for efficient loss-of-function studies of genes and genetic elements in mammalian cell lines.

CRISPR/Cas9 is a robust system to produce disruption of genes and genetic elements. Here we describe a protocol for the efficient creation of genomic deletions in mammalian cell lines using CRISPR/Cas9.

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific ...

Silencing the Spark: CRISPR/Cas9 Genome Editing in Weakly Electric Fish

Electroreception and electrogenesis have changed in the evolutionary history of vertebrates. There is a striking degree of convergence in these independently derived phenotypes, which share a common genetic architecture. This is perhaps best exemplified by the numerous convergent features of gymnotiforms and mormyrids, two species-rich teleost clades that produce and detect weak electric fields and are called weakly electric fish. In the 50 years since the discovery that weakly electric fish use electricity to sense their surroundings and communicate, a growing community of scientists has gained tremendous insights into evolution of development, systems and circuits neuroscience, cellular physiology, ecology, evolutionary biology, and behavior. More recently, there has been a proliferation of genomic resources for electric fish. Use of these resources has already facilitated important insights with regards to the connection between genotype and phenotype in these species. A major obstacle to integrating genomics data with phenotypic data of weakly electric fish is a present lack of functional genomics tools. We report here a full protocol for performing CRISPR/Cas9 mutagenesis that utilizes endogenous DNA repair mechanisms in weakly electric fish. We demonstrate that this protocol is equally effective in both the mormyrid species Brienomyrus brachyistius and the gymnotiform Brachyhypopomus gauderio by using CRISPR/Cas9 to target indels and point mutations in the first exon of the sodium channel gene scn4aa. Using this protocol, embryos from both species were obtained and genotyped to confirm that the predicted mutations in the first exon of the sodium channel scn4aa were present. The knock-out success phenotype was confirmed with recordings showing reduced electric organ discharge amplitudes when compared to uninjected size-matched controls.

Here, a protocol is presented to produce and rear CRISPR/Cas9 genome knockout electric fish. Outlined in detail are the required molecular biology, breeding, and husbandry requirements for both a gymnotiform and a mormyrid, and injection techniques to produce Cas9-induced indel F0 larvae.

Electroreception and electrogenesis have changed in the evolutionary history of vertebrates. There is a striking degree of convergence in these ...

Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9

Culex mosquitoes are the major vectors of several diseases that negatively impact human and animal health including West Nile virus and diseases caused by filarial nematodes such as canine heartworm and elephantasis. Recently, CRISPR/Cas9 genome editing has been used to induce site-directed mutations by injecting a Cas9 protein that has been complexed with a guide RNA (gRNA) into freshly laid embryos of several insect species, including mosquitoes that belong to the genera Anopheles and Aedes. Manipulating and injecting Culex mosquitoes is slightly more difficult as these mosquitoes lay their eggs upright in rafts rather than individually like other species of mosquitoes. Here we describe how to design gRNAs, complex them with Cas9 protein, induce female mosquitoes of Culex pipiens to lay eggs, and how to prepare and inject newly laid embryos for microinjection with Cas9/gRNA. We also describe how to rear and screen injected mosquitoes for the desired mutation. The representative results demonstrate that this technique can be used to induce site-directed mutations in the genome of Culex mosquitoes and, with slight modifications, can be used to generate null-mutants in other mosquito species as well.&#160;

Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9

CRISPR/Cas9 is increasingly used to characterize gene function in non-model organisms. This protocol describes how to generate knock-out lines of Culex pipiens, from preparing injection mixes, to obtaining and injecting mosquito embryos, as well as how to rear, cross, and screen injected mosquitoes and their progeny for desired mutations.

Culex mosquitoes are the major vectors of several diseases that negatively impact human and animal health including West Nile virus and diseases caused by ...

Genome Engineering of Primary Human B Cells Using CRISPR/Cas9

B cells are lymphocytes derived from hematopoietic stem cells and are a key component of the humoral arm of the adaptive immune system. They make attractive candidates for cell-based therapies because of their ease of isolation from peripheral blood, their ability to expand in vitro, and their longevity in vivo. Additionally, their normal biological function&#8212;to produce large amounts of antibodies&#8212;can be utilized to express very large amounts of a therapeutic protein, such as a recombinant antibody to fight infection, or an enzyme for the treatment of enzymopathies. Here, we provide detailed methods for isolating primary human B cells from peripheral blood mononuclear cells (PBMCs) and activating/expanding isolated B cells in vitro. We then demonstrate the steps involved in using the CRISPR/Cas9 system for site-specific KO of endogenous genes in B cells. This method allows for efficient KO of various genes, which can be used to study the biological functions of genes of interest. We then demonstrate the steps for using the CRISPR/Cas9 system together with a recombinant, adeno-associated, viral (rAAV) vector for efficient site-specific integration of a transgene expression cassette in B cells. Together, this protocol provides a step-by-step engineering platform that can be used in primary human B cells to study biological functions of genes as well as for the development of B-cell therapeutics.

Here we provide a detailed, step-by-step protocol for CRISPR/Cas9-based genome engineering of primary human B cells for gene knockout (KO) and knock-in (KI) to study biological functions of genes in B cells and the development of B-cell therapeutics.

B cells are lymphocytes derived from hematopoietic stem cells and are a key component of the humoral arm of the adaptive immune system. They make ...

Construction of Homozygous Mutants of Migratory Locust Using CRISPR/Cas9 Technology

The migratory locust, Locusta migratoria, is not only one of the worldwide plague locusts that caused huge economic losses to human beings but also an important research model for insect metamorphosis. The CRISPR/Cas9 system can accurately locate at a specific DNA locus and cleave within the target site, efficiently introducing double-strand breaks to induce target gene knockout or integrate new gene fragments into the specific locus. CRISPR/Cas9-mediated genome editing is a powerful tool for addressing questions encountered in locust research as well as a promising technology for locust control. This study provides a systematic protocol for CRISPR/Cas9-mediated gene knockout with the complex of Cas9 protein and single guide RNAs (sgRNAs) in migratory locusts. The selection of target sites and design of sgRNA are described in detail, followed by in vitro synthesis and verification of the sgRNAs. Subsequent procedures include egg raft collection and tanned-egg separation to achieve successful microinjection with low mortality rate, egg culture,&#160;preliminary estimation of the mutation rate, locust breeding as well as detection, preservation, and passage of the mutants to ensure population stability of the edited locusts. This method can be used as a reference for CRISPR/Cas9 based gene editing applications in migratory locusts as well as in other insects.

This study provides a systematically optimized procedure of CRISPR/Cas9 ribonuclease-based construction of homozygous locust mutants as well as a detailed method for cryopreservation and resuscitation of the locust eggs.

The migratory locust, Locusta migratoria, is not only one of the worldwide plague locusts that caused huge economic losses to human beings but also an ...

CRISPR/Cas9 Gene Editing of Hematopoietic Stem and Progenitor Cells for Gene Therapy Applications

CRISPR/Cas9 is a highly versatile and efficient gene-editing tool adopted widely to correct various genetic mutations. The feasibility of gene manipulation of hematopoietic stem and progenitor cells (HSPCs) in vitro makes HSPCs an ideal target cell for gene therapy. However, HSPCs moderately lose their engraftment and multilineage repopulation potential in ex vivo culture. In the present study, ideal culture conditions are described that improves HSPC engraftment and generate an increased number of gene-modified cells in vivo. The current report displays optimized in vitro culture conditions, including the type of culture media, unique small molecule cocktail supplementation, cytokine concentration, cell culture plates, and culture density. In addition to that, an optimized HSPC gene-editing procedure, along with the validation of the gene-editing events, are provided. For in vivo validation, the gene-edited HSPCs infusion and post-engraftment analysis in mouse recipients are displayed. The results demonstrated that the culture system increased the frequency of functional HSCs in vitro, resulting in robust engraftment of gene-edited cells in vivo.

The present protocol describes an optimized hematopoietic stem and progenitor cell (HSPC) culture procedure for the robust engraftment of gene-edited cells in vivo.

CRISPR/Cas9 is a highly versatile and efficient gene-editing tool adopted widely to correct various genetic mutations. The feasibility of gene ...

CRISPR-Cas9-Mediated Precise Knock-In Edits in Zebrafish Hearts

Clustered regularly interspaced short palindromic repeats (CRISPR) in animal models enable precise genetic manipulation for the study of physiological phenomena. Zebrafish have been used as an effective genetic model to study numerous questions related to heritable disease, development, and toxicology at the whole-organ and -organism level. Due to the well-annotated and mapped zebrafish genome, numerous tools for gene editing have been developed. However, the efficacy of generating and ease of detecting precise knock-in edits using CRISPR is a limiting factor. Described here is a CRISPR-Cas9-based knock-in approach with the simple detection of precise edits in a gene responsible for cardiac repolarization and associated with the electrical disorder, Long QT Syndrome (LQTS). This two-single-guide RNA (sgRNA) approach excises and replaces the target sequence and links a genetically encoded reporter gene. The utility of this approach is demonstrated by describing non-invasive phenotypic measurements of cardiac electrical function in wild-type and gene-edited zebrafish larvae. This approach enables the efficient study of disease-associated variants in a whole organism. Furthermore, this strategy offers possibilities for the insertion of exogenous sequences of choice, such as reporter genes, orthologs, or gene editors.

This protocol describes an approach to facilitate precise knock-in edits in zebrafish embryos using CRISPR-Cas9 technology. A phenotyping pipeline is presented to demonstrate the applicability of these techniques to model a Long QT Syndrome-associated gene variant.

Clustered regularly interspaced short palindromic repeats (CRISPR) in animal models enable precise genetic manipulation for the study of physiological ...

Centromere-Associated Protein-E Gene Editing Using the CRISPR/Cas9 System

Generation of Centromere-Associated Protein-E CENP-E-/- Knockout Cell Lines using the CRISPR/Cas9 System

The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system has emerged as a powerful tool for precise and efficient gene editing in a variety of organisms. Centromere-associated protein-E (CENP-E) is a plus-end-directed kinesin required for kinetochore-microtubule capture, chromosome alignment, and spindle assembly checkpoint. Although cellular functions of the CENP-E proteins have been well studied, it has been difficult to study the direct functions of CENP-E proteins using traditional protocols because CENP-E ablation usually leads to spindle assembly checkpoint activation, cell cycle arrest, and cell death. In this study, we have completely knocked out the CENP-E gene in human HeLa cells and successfully generated the CENP-E-/- HeLa cells using the CRISPR/Cas9 system.
Three optimized phenotype-based screening strategies were established, including cell colony screening, chromosome alignment phenotypes, and the fluorescent intensities of CENP-E proteins, which effectively improve the screening efficiency and experimental success rate of the CENP-E knockout cells. Importantly, CENP-E deletion results in chromosome misalignment, the abnormal location of the BUB1 mitotic checkpoint serine/threonine kinase B (BubR1) proteins, and mitotic defects. Furthermore, we have utilized the CENP-E knockout HeLa cell model to develop an identification method for CENP-E-specific inhibitors.
In this study, a useful approach to validate the specificity and toxicity of CENP-E inhibitors has been established. Moreover, this paper presents the protocols of CENP-E gene editing using the CRISPR/Cas9 system, which could be a powerful tool to investigate the mechanisms of CENP-E in cell division. Moreover, the CENP-E&#160;knockout cell line would contribute to the discovery and validation of CENP-E inhibitors, which have important implications for antitumor drug development, studies of cell division mechanisms in cell biology, and clinical applications.

Author Spotlight: Establishing &lt;em&gt;CENP-E&lt;/em&gt; Knockout HeLa Cells &amp;#8211; A Novel Approach to Study Kinesin-7 &lt;em&gt;CENP-E&lt;/em&gt; Biology and its Inhibitors

This article reports the construction of centromere-associated protein-E (CENP-E) knockout cells using the CRISPR/Cas9 system and three phenotype-based screening strategies. We have utilized the CENP-E&#160;knockout cell line to establish a novel approach to validate the specificity and toxicity of the CENP-E inhibitors, which is useful for drug development and biological research.

The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system has emerged as a powerful tool for precise and efficient gene editing ...