你为么会怕蜘蛛?是因为有毒么?
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">“啊,蜘蛛!”</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">非常多</span>人在看到蜘蛛时,不仅会感到害怕,<span style="color: black;">乃至</span>还会不由自主地发出尖叫。这其实是一种<span style="color: black;">平常</span>的,对某种特定动物的恐惧症——蜘蛛恐惧症,大<span style="color: black;">大概</span>2.7%~6.1%的人群会受到这一病症的影响。</p>
<div style="color: black; text-align: left; margin-bottom: 10px;"><img src="https://p3-sign.toutiaoimg.com/tos-cn-i-6w9my0ksvp/333cbc85e7114053b18c4cbb6d271d70~noop.image?_iz=58558&from=article.pc_detail&lk3s=953192f4&x-expires=1725098248&x-signature=ofX3Zck%2BT7ytsHR96TMJatXZg6g%3D" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛的螯肢(<span style="color: black;">照片</span><span style="color: black;">源自</span>:wikipedia)</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">谈及蜘蛛时,有毒似乎是<span style="color: black;">大众</span>的<span style="color: black;">第1</span>印象,事实<span style="color: black;">亦</span>正是如此。<strong style="color: blue;"><span style="color: black;">尽管蜘蛛不是民间所说的“五毒”之一,但在已知的约50000个蜘蛛物种中,绝大部分的种类都会产生<span style="color: black;">有些</span>毒液。</span></strong>大<span style="color: black;">都数</span>蜘蛛依靠毒液来<span style="color: black;">守护</span>自己和进行捕猎,它们会<span style="color: black;">经过</span>自己的螯牙将毒腺中的毒液注入到猎物<span style="color: black;">身体</span>,使猎物麻痹、溶解或死亡,而后再享用吸食。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">那样</span>,人们<span style="color: black;">针对</span>蜘蛛的恐惧是<span style="color: black;">由于</span>蜘蛛有毒吗?</p>
<h1 style="color: black; text-align: left; margin-bottom: 10px;">被“误解”的毒蜘蛛</h1>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">事实上,在抗毒血清投入<span style="color: black;">运用</span>之后,全世界每年<span style="color: black;">亡于</span>蜘蛛咬伤的人数大都是个位数。换句话说,被蜘蛛毒死的人数可能还不如<span style="color: black;">由于</span>受到蜘蛛惊吓<span style="color: black;">出现</span>意外而死亡的人数多。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">尽管<span style="color: black;">都数</span>蜘蛛都会产生毒液,但<span style="color: black;">专家</span>们估计,<span style="color: black;">仅有</span>0.5%的蜘蛛物种对人类<span style="color: black;">拥有</span>潜在的危险,<span style="color: black;">由于</span>大<span style="color: black;">都数</span>蜘蛛的螯肢并<span style="color: black;">不可</span>穿透人类的皮肤,它们的叮咬只会<span style="color: black;">导致</span>适度的短期影响。<span style="color: black;">因此呢</span>,<strong style="color: blue;"><span style="color: black;">大多数蜘蛛本质上是无害的</span></strong>。</p>
<div style="color: black; text-align: left; margin-bottom: 10px;"><img src="https://p3-sign.toutiaoimg.com/tos-cn-i-6w9my0ksvp/7e45311129854c509c8083ec90e1e733~noop.image?_iz=58558&from=article.pc_detail&lk3s=953192f4&x-expires=1725098248&x-signature=WZGcVqqTkIt3krXZY9rYC0pBbH0%3D" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">被蜘蛛叮咬后留下的伤口(<span style="color: black;">照片</span><span style="color: black;">源自</span>:wikipedia)</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">既然<span style="color: black;">这般</span>,人们<span style="color: black;">针对</span>蜘蛛的恐惧<span style="color: black;">到底</span>从何而来呢?</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">有人推测,人类的祖先或许和<span style="color: black;">哪些</span>危险的蜘蛛物种<span style="color: black;">出现</span>过接触,<span style="color: black;">她们</span>之间的<span style="color: black;">一起</span>演化<span style="color: black;">引起</span>了人类<span style="color: black;">针对</span>蜘蛛的<span style="color: black;">消极</span><span style="color: black;">心情</span>。但其实这一推论并不太可能,<span style="color: black;">由于</span><span style="color: black;">哪些</span><span style="color: black;">能够</span>威胁人类的蜘蛛<span style="color: black;">重点</span>分布在澳洲和南美洲,在人类起源的非洲其实并不<span style="color: black;">平常</span>。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">思虑</span>到这些<span style="color: black;">原由</span>,<strong style="color: blue;"><span style="color: black;"><span style="color: black;">专家</span>们认为人类对蝎子的恐惧可能是蜘蛛恐惧症的<span style="color: black;">基本</span><span style="color: black;">源自</span></span></strong>。蝎子与蜘蛛有<span style="color: black;">类似</span>的身体结构,但与蜘蛛<span style="color: black;">区别</span>的是,蝎子<span style="color: black;">能够</span>对人类<span style="color: black;">形成</span>真正的威胁:每年全世界<span style="color: black;">报告</span>了约 150 万起蝎子伤人的事件,<span style="color: black;">导致</span>约2600人死亡,而北非和中东是受影响最严重的地区。</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">土耳其黑肥尾蝎(图片<span style="color: black;">源自</span>:wikipedia)</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">因此呢</span>,<span style="color: black;">科研</span>者们招募了超过300名志愿者,向<span style="color: black;">她们</span>展示了<span style="color: black;">包含</span>蜘蛛、蝎子、蟑螂和其他昆虫在内的62种节肢动物的活体,让<span style="color: black;">她们</span><span style="color: black;">按照</span>自己的感知对其进行打分(参考文献1)。结果<span style="color: black;">表示</span>,蝎子、蜘蛛和其他蛛形纲动物在恐惧和厌恶方面的得分最高,<span style="color: black;">因此</span><span style="color: black;">专家</span>们推测,人类<span style="color: black;">针对</span>蜘蛛的恐惧可能只是<span style="color: black;">针对</span>这类生物的<span style="color: black;">广泛</span>恐惧所<span style="color: black;">诱发</span>的,而蝎子则是<span style="color: black;">引起</span>这类恐惧症的原始刺激物。当然,这一结论<span style="color: black;">亦</span>只是<span style="color: black;">专家</span>们<span style="color: black;">针对</span>蜘蛛恐惧症的一个可能解释,但人们<span style="color: black;">针对</span>蜘蛛和蝎子的厌恶却<span style="color: black;">亦</span>是不争的事实。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">虽然蜘蛛的毒液<span style="color: black;">针对</span>人类的影响相对有限,但毒液<span style="color: black;">针对</span>蜘蛛本身却<span style="color: black;">非常</span>重要。</span></strong>凭借着毒液这一强大的武器,蜘蛛们<span style="color: black;">已然</span>成功征服了除南极洲之外的每一个大陆,从陆地到水中,从荒漠到雨林,<span style="color: black;">乃至</span>是潮水褪去后海滩边的水洼里,都<span style="color: black;">能够</span><span style="color: black;">发掘</span>蜘蛛的身影。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛毒液里<span style="color: black;">到底</span>有些啥呢?</p>
<h1 style="color: black; text-align: left; margin-bottom: 10px;">蜘蛛毒液:极度危险的“鸡尾酒”</h1>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛毒液的<span style="color: black;">成份</span><span style="color: black;">非常</span><span style="color: black;">繁杂</span>,<span style="color: black;">包括</span>数千种<span style="color: black;">区别</span>的<span style="color: black;">成份</span>,将其比喻成“一种极度危险的鸡尾酒”<span style="color: black;">亦</span>不为过。<span style="color: black;">详细</span>而言,<strong style="color: blue;"><span style="color: black;">蜘蛛毒液中的<span style="color: black;">成份</span><span style="color: black;">能够</span>分为四种:小分子、分子量<span style="color: black;">很强</span>的蛋白质、<span style="color: black;">饱含</span>二硫键的毒素多肽以及抗菌肽</span></strong>。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">其中,小分子<span style="color: black;">包括</span>了血清素、章鱼胺、5-羟色胺、5-甲氧基色胺、组胺、酪胺、γ-氨基丁酸、天冬氨酸和谷氨酸等神经递质,还有柠檬酸盐、无机离子和盐等物质。这类小分子物质中被<span style="color: black;">科研</span>得最多的是酰基多胺,这些多胺最早于上世纪80年代在金蛛属和人面蜘蛛属的物种中<span style="color: black;">发掘</span>,是一种杀虫的神经毒素。</p>
<div style="color: black; text-align: left; margin-bottom: 10px;"><img src="https://p3-sign.toutiaoimg.com/tos-cn-i-6w9my0ksvp/8249bebf198c446fbfb8f9af13e71a65~noop.image?_iz=58558&from=article.pc_detail&lk3s=953192f4&x-expires=1725098248&x-signature=qJVaKFAIeLqpxzRo7%2FJ44IJUZ4A%3D" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛毒液中<span style="color: black;">拥有</span><span style="color: black;">表率</span>性的蛋白(上)、毒素多肽(中)和抗菌肽(下)(<span style="color: black;">照片</span><span style="color: black;">源自</span>:参考文献2)</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛毒液中分子量<span style="color: black;">很强</span>的蛋白质的重要性和丰度<span style="color: black;">日前</span>仍然存在争议,但在<span style="color: black;">有些</span>蜘蛛类群中,这些蛋白质构<span style="color: black;">成为了</span>毒液的关键<span style="color: black;">成份</span>,<span style="color: black;">例如</span>黑寡妇蜘蛛毒液中的α-蜘蛛毒素以及其他<span style="color: black;">有些</span>种类中的磷脂酶D。而毒液中的抗菌肽则<span style="color: black;">能够</span>通过破坏真核细胞膜的完整性来损害真核细胞,<span style="color: black;">因此呢</span><span style="color: black;">亦</span>被<span style="color: black;">叫作</span>为裂解肽。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">在蜘蛛毒液中起到最重要<span style="color: black;">功效</span>的是<span style="color: black;">哪些</span><span style="color: black;">饱含</span>二硫键的多肽,它们的分子量<span style="color: black;">一般</span><span style="color: black;">小于</span>10kDa。这些多肽<span style="color: black;">能够</span>与离子通道<span style="color: black;">或</span>其他受体相互<span style="color: black;">功效</span>,<span style="color: black;">表率</span>了蜘蛛毒液的<span style="color: black;">重点</span>神经毒性<span style="color: black;">成份</span>。</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">虽然蜘蛛毒液中都有毒素多肽,这些<span style="color: black;">饱含</span>二硫键的肽<span style="color: black;">乃至</span><span style="color: black;">能够</span>占到蜘蛛毒液<span style="color: black;">重点</span><span style="color: black;">成份</span>的四分之三,但<span style="color: black;">区别</span>蜘蛛类群中的多肽种类<span style="color: black;">能够</span>说是千差万别,各自<span style="color: black;">拥有</span>独特的多样性。因而它们的起源和演化<span style="color: black;">始终</span><span style="color: black;">败兴</span>都是一个让生物学家们感到困惑的问题。</p>
<h1 style="color: black; text-align: left; margin-bottom: 10px;">毒,从何而来?</h1>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">近期</span>一项<span style="color: black;">发布</span>在期刊eLife上的<span style="color: black;">科研</span>就<span style="color: black;">以上</span>问题给出了一个可能的答案(参考文献3)。为了<span style="color: black;">认识</span>蜘蛛毒液中五花八门的毒素多肽从何而来,<span style="color: black;">科研</span>人员获取了迄今为止生成的所有蜘蛛毒素多肽的序列数据来追溯它们的演化历史。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">科研</span>的结果<span style="color: black;">显示</span>,<strong style="color: blue;"><span style="color: black;"><span style="color: black;">日前</span><span style="color: black;">已然</span>测序的所有毒素多肽都可能源于一个<span style="color: black;">一起</span>的祖先多肽</span></strong>,这种祖先毒素被<span style="color: black;">专家</span>们命名为阿迪·沙克蒂(Adi Shakti)——印度教中的太初之母。为了区分<span style="color: black;">区别</span>的毒素超家族,<span style="color: black;">专家</span>们还用<span style="color: black;">区别</span>文化中与死亡、毁灭和冥界<span style="color: black;">相关</span>的神灵的名字来为它们命名。</p>
<div style="color: black; text-align: left; margin-bottom: 10px;"><img src="https://p3-sign.toutiaoimg.com/tos-cn-i-6w9my0ksvp/3727a87fbf384994a38172952fac9e72~noop.image?_iz=58558&from=article.pc_detail&lk3s=953192f4&x-expires=1725098248&x-signature=KMJdvG%2F1fTSR4f38unRNQhJc2ME%3D" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">基于蜘蛛毒素多肽序列的系统<span style="color: black;">出现</span>树(<span style="color: black;">照片</span><span style="color: black;">源自</span>:参考文献3)</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">按照</span><span style="color: black;">科研</span>,<span style="color: black;">专家</span>们推测,在大约3.75亿年前,这种祖先毒素就存在于现代蜘蛛的<span style="color: black;">近期</span><span style="color: black;">一起</span>祖先<span style="color: black;">身体</span>,而后,<span style="color: black;">饱含</span>二硫键的毒素多肽<span style="color: black;">由于</span><span style="color: black;">区别</span>的<span style="color: black;">选取</span>压力在<span style="color: black;">区别</span>的蜘蛛类群中<span style="color: black;">出现</span>了多样化。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">不仅如此,毒素多肽多样化的速度在<span style="color: black;">区别</span>的蜘蛛类群间还有所<span style="color: black;">区别</span>:在<span style="color: black;">哪些</span>依靠毒液来进行狩猎的蜘蛛类群中,<span style="color: black;">由于</span>“猎人”可能需要<span style="color: black;">持续</span><span style="color: black;">得到</span><span style="color: black;">拥有</span>新<span style="color: black;">功效</span>和新结构的毒素来保持对“猎物”的<span style="color: black;">优良</span>,这些多肽的演化速率要更快<span style="color: black;">有些</span>;而在<span style="color: black;">哪些</span>依靠毒液来自卫的蜘蛛物种中,<span style="color: black;">因为</span><span style="color: black;">运用</span>频率较低,毒素多肽表现出较低的多样性。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">当然,关于蜘蛛毒液的起源问题并<span style="color: black;">不可</span>仅靠一项<span style="color: black;">科研</span>就能说清,事实上,不仅是蜘蛛的毒液,它们的毒腺从何而来<span style="color: black;">亦</span>是一个悬而未决的问题。</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">在之前的<span style="color: black;">科研</span>中,<span style="color: black;">有些</span><span style="color: black;">专家</span>认为蜘蛛的毒腺可能起源于唾液腺,类似于蜱虫,而蜱虫又和蜘蛛<span style="color: black;">拥有</span><span style="color: black;">近期</span>的<span style="color: black;">一起</span>祖先,<span style="color: black;">因此</span>蜘蛛的毒腺可能是进化的唾液腺。<span style="color: black;">另一</span><span style="color: black;">有些</span><span style="color: black;">专家</span>则认为,蜘蛛的毒腺<span style="color: black;">亦</span>可能起源于古老的产丝腺体,<span style="color: black;">由于</span>在海蜘蛛的某些物种中,其幼虫的螯肢<span style="color: black;">拥有</span>分泌性丝腺。但<span style="color: black;">因为</span>缺乏<span style="color: black;">关联</span>证据,<span style="color: black;">专家</span>们<span style="color: black;">亦</span><span style="color: black;">不可</span>确定这两个假说哪个更加<span style="color: black;">可靠</span>。</p>
<div style="color: black; text-align: left; margin-bottom: 10px;"><img src="https://p3-sign.toutiaoimg.com/tos-cn-i-6w9my0ksvp/fa262d93770a47ce92a044ba0267215c~noop.image?_iz=58558&from=article.pc_detail&lk3s=953192f4&x-expires=1725098248&x-signature=qT4XLLZdqYQ2zllcY5G5c6xm6sQ%3D" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛毒腺起源的两种假说:唾液腺起源假说(左)和产丝腺体起源假说(<span style="color: black;">照片</span><span style="color: black;">源自</span>:参考文献4)</p>
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<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">针对这个问题,<span style="color: black;">近期</span>的一项基于基因组和转录组数据的<span style="color: black;">科研</span>认为,<strong style="color: blue;"><span style="color: black;">蜘蛛毒腺更可能起源于古老的产丝腺体</span></strong>。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">科研</span>人员获取了<span style="color: black;">包含</span>蜘蛛、蝎子、蜱、螨、蜈蚣以及<span style="color: black;">有些</span>昆虫在内的<span style="color: black;">区别</span>物种的基因组和转录组数据,<span style="color: black;">经过</span>分析鉴定出了与毒腺<span style="color: black;">拥有</span>较强功能<span style="color: black;">关联</span>性的基因。进一步,<span style="color: black;">她们</span>比较了蜘蛛毒腺和其他腺体组织之间在分子特征上的<span style="color: black;">类似</span>性,<span style="color: black;">发掘</span>蜘蛛毒腺在转录调控方面与唾液腺的<span style="color: black;">类似</span>性<span style="color: black;">少于</span>与丝腺的<span style="color: black;">类似</span>性。<span style="color: black;">因此呢</span>,<span style="color: black;">研究</span>人员们推测蜘蛛毒腺可能独立起源于古老的产丝腺体。<span style="color: black;">不外</span>,这项<span style="color: black;">科研</span>的取样还有待进一步完善,关于蜘蛛毒腺的起源仍需要更加全面的<span style="color: black;">科研</span>。</p>
<h1 style="color: black; text-align: left; margin-bottom: 10px;">结语</h1>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">正如前面所<span style="color: black;">说到</span>的,蜘蛛的毒液对人类的影响并不如<span style="color: black;">大众</span>想象中<span style="color: black;">那样</span>大,但人们<span style="color: black;">针对</span>蜘蛛的影响却显而易见。近年来,随着“异宠热”的兴起,蜘蛛越来越受到宠物饲养者的欢迎,<span style="color: black;">有些</span>蜘蛛<span style="color: black;">乃至</span>还<span style="color: black;">由于</span>广泛的贸易而濒临灭绝。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">相比于在家中饲养,对蜘蛛敬而远之或许是更好的<span style="color: black;">选取</span>。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">作者:EVEE</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">作者单位:北京大学生命科学学院</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">参考文献:</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">Frynta, D., Janovcová, M., Štolhoferová, I., Peléšková, Š., Vobrubová, B., Frýdlová, P., ... & Landová, E. (2021). Emotions triggered by live arthropods shed light on spider phobia. Scientific Reports, 11(1), 22268.</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">Lüddecke, T., Herzig, V., Von Reumont, B. M., & Vilcinskas, A. (2022). The biology and evolution of spider venoms. Biological Reviews, 97(1), 163-178.</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">Shaikh, N. Y., & Sunagar, K. (2023). The deep-rooted origin of disulfide-rich spider venom toxins. eLife, 12, e83761.</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">Zhu, B., Jin, P., Zhang, Y., Shen, Y., Wang, W., & Li, S. (2023). Genomic and transcriptomic analyses support a silk gland origin of spider venom glands. BMC</span><span style="color: black;"> biology, 21(1), 1-17.</span></p>
回顾过去一年,是艰难的一年;展望未来,是辉煌的一年。 “沙发”(SF,第一个回帖的人) 大势所趋,用于讽刺一些制作目的就是为了跟风玩梗,博取眼球的作品。
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