Development and improvement of ‘functional neural cellomics’ to elucidate the structure‐function relationships of neural networks of Caenorhabditis elegans
Development and improvement of ‘functional neural cellomics’ to elucidate the structure‐function relationships of neural networks of Caenorhabditis elegans
复制标题
开发和改进“功能神经细胞组学”以阐明秀丽隐杆线虫神经网络的结构功能关系
DOI:
10.1096/fasebj.2020.34.s1.03223
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发表时间:
2020
期刊:
影响因子:
--
通讯作者:
Ueda Mitsuyoshi
中科院分区:
文献类型:
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作者:
Yamauchi Yuji;Aoki Wataru;Ueda Mitsuyoshi
BackgroundA nervous system generates complex behaviors. However, relationships between neural computation and behaviors have hardly been elucidated. Optogenetics is a powerful technique for investigating mechanisms of neural computation. However, conventional optogenetics has three problems: (1) a hypothesis is required before an experiment; (2) the throughput is low because we should generate appropriate transgenic animals to test each hypothesis; (3) single‐cell analysis is difficult because few single‐cell‐specific promoters are known. To solve these problems, we have developed a new methodology ‘functional neural cellomics’ which enables comprehensive elucidation of relationships between behaviors and neural networks ofCaenorhabditis elegans.MethodThe core technology of functional neural cellomics is the stochastic labeling of opsin in the neural network ofC. elegans. The stochastic labeling of opsin was implemented by applying the Cre‐loxsystem. We designed a genetics circuit in which two sets of lox variants,lox2272andloxPsequences, are inserted alternately downstream of pan‐neuronal F25B3.3 promoter. In addition, mCherry and a transcription factor, QF2w, are interposed between theseloxsequences. After the induction of Cre recombinase by heat shock, a Cre‐loxrecombination event occurs exclusively either betweenlox2272sequences or betweenloxPsequences. If Cre is allowed to act onlox2272sequences, QF2w is expressed. Then, QF2w induces expression of ChR2::GFP. In this way, we can easily acquire aC. eleganslibrary in which ChR2 is labeled in a stochastic manner in each animal.Results & DiscussionBy inducing Cre recombinase, we confirmed that ChR2::GFP was labeled in a stochastic manner in each animal. To verify the feasibility of functional neural cellomics, we tried to demonstrate that neurons involved in the egg‐laying behavior ofC. eleganscould be identified in a high‐throughput manner. TheC. eleganslibrary was irradiated with blue light to activate ChR2, and we found some animals laid eggs in a blue‐light‐dependent manner. We identified neurons producing ChR2 using a confocal microscope, and confirmed that ChR2::GFP was expressed in HSNs (hermaphrodite‐specific neurons) in the egg‐laying individuals, but was not in the non‐egg laying individuals [1].In the above experiment, we found that the labeling rate of opsin was about 30%. If opsin is labeled in too many neurons, it becomes difficult to distinguish the function of individual neurons. To enable precise control of the labeling rate, we generated a library of randomized lox sequences by PCR. We evaluated excision efficiencies of theloxvariants by using NGS, and successfully identifiedloxvariant sequences which showed excision efficiencies ranging from 0.01% to 100%. Using theseloxvariants, we will be able to improve functional neural cellomics for comprehensive intervention in neural networks and high‐throughput identification of neural functions.Support or Funding InformationThis work was supported by PRESTO, JST (grant No. JPMJPR16F1), JSPS KAKENHI (grant No. JP17K19452), and Kyoto University Live Imaging Center.[1]Aoki et. al. Sci Rep 8, 10380 ( 2018)