Context-dependent hyperactivity in syngap1a and syngap1b zebrafish autism models.
Context-dependent hyperactivity in syngap1a and syngap1b zebrafish autism models.
复制标题
syngap1a 和 syngap1b 斑马鱼自闭症模型中的情境依赖性过度活跃。
DOI：
10.1101/2023.09.20.557316
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Dallman,JuliaE
中科院分区：
文献类型：
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作者：
Sumathipala,SureniH;Khan,Suha;Kozol,RobertA;Araki,Yoichi;Syed,Sheyum;Huganir,RichardL;Dallman,JuliaE
背景和目的SYNGAP1障碍是自闭症谱系障碍和智能障碍(ASD/ID)的一种常见的遗传形式，由SYNGAP1基因的一个拷贝的从头突变或遗传性突变引起。除了ASD/ID，SYNGAP1障碍还与共病症状有关，包括难治性癫痫、睡眠障碍和胃肠道不适。这些不同的症状和SYNGAP1变异之间的机制联系仍然不清楚，因此，我们的目标是建立一个可以研究这一范围的症状的斑马鱼模型。方法我们使用CRISPR/Cas9在Syngap1a和syngap1b的重复序列(Syngap1ab)中引入移码突变，并验证了这些稳定的Syngap1功能丧失模型。由于SYNGAP1被广泛剪接，我们将剪接变体定位于斑马鱼的两个syngap1a和b基因，并确定了类似哺乳动物的异构体。然后我们量化了斑马鱼syngap1ab幼虫在三种条件下的运动行为，这三种条件通常会在野生型幼虫中引起不同的唤醒状态：厌恶、高唤醒声音、中等唤醒黑暗和低唤醒光刺激。结果我们发现斑马鱼syngap1a和syngap1b中的CRISPR/Cas9内含子在RNA和蛋白质水平上产生了功能丧失的等位基因。我们对斑马鱼Syngap1亚型的分析表明，与哺乳动物一样，斑马鱼Syngap1的N-末端和C-末端广泛剪接。我们发现了一个斑马鱼Syngap1α1类变体，它专门映射到Syngap1b基因。量化运动行为表明，与野生型相比，syngap1ab幼虫活动过度，但程度因刺激而异。在低觉醒环境下，多动症最为明显，随着突变型Syngap1等位基因数量的增加，整体运动增加。结论我们的数据支持斑马鱼Syngap1ab突变是与高觉醒相关的多动症的原因，这在低觉醒环境中尤其明显。
Background and AimsSYNGAP1 disorder is a prevalent genetic form of Autism Spectrum Disorder and Intellectual Disability (ASD/ID) and is caused by de novo or inherited mutations in one copy of the SYNGAP1 gene. In addition to ASD/ID, SYNGAP1 disorder is associated with comorbid symptoms including treatment-resistant-epilepsy, sleep disturbances, and gastrointestinal distress. Mechanistic links between these diverse symptoms and SYNGAP1 variants remain obscure, therefore, our goal was to generate a zebrafish model in which this range of symptoms can be studied.MethodsWe used CRISPR/Cas9 to introduce frameshift mutations in the syngap1a and syngap1b zebrafish duplicates (syngap1ab) and validated these stable models for Syngap1 loss-of-function. Because SYNGAP1 is extensively spliced, we mapped splice variants to the two zebrafish syngap1a and b genes and identified mammalian-like isoforms. We then quantified locomotory behaviors in zebrafish syngap1ab larvae under three conditions that normally evoke different arousal states in wild type larvae: aversive, high-arousal acoustic, medium-arousal dark, and low-arousal light stimuli.ResultsWe show that CRISPR/Cas9 indels in zebrafish syngap1a and syngap1b produced loss-of-function alleles at RNA and protein levels. Our analyses of zebrafish Syngap1 isoforms showed that, as in mammals, zebrafish Syngap1 N- and C-termini are extensively spliced. We identified a zebrafish syngap1 α1-like variant that maps exclusively to the syngap1b gene. Quantifying locomotor behaviors showed that syngap1ab larvae are hyperactive compared to wild type but to differing degrees depending on the stimulus. Hyperactivity was most pronounced in low arousal settings, with overall movement increasing with the number of mutant syngap1 alleles.ConclusionsOur data support mutations in zebrafish syngap1ab as causal for hyperactivity associated with elevated arousal that is especially pronounced in low-arousal environments.