Identification and characterization of two CRISPR/Cas systems associated with the mosquito microbiome.
Identification and characterization of two CRISPR/Cas systems associated with the mosquito microbiome.
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DOI：
10.1099/acmi.0.000599.v4
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发表时间：
2023
影响因子：
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通讯作者：
Shariat, Nikki
中科院分区：
文献类型：
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作者：
Hegde, Shivanand;Rauch, Hallie E;Hughes, Grant L;Shariat, Nikki
微生物组深刻地影响了蚊子等医学相关载体的许多特征，对宿主与微生物相互作用的更深入的功能了解可能有助于开发基于微生物的新方法来控制蚊子传播的疾病。在这里，我们表征了沙雷氏菌中两个新颖的成簇规则间隔短回文重复（CRISPR）/Cas系统。 Ag1，从冈比亚按蚊的肠道中分离出来。在沙雷氏菌 Ag1 中鉴定出两种不同的 CRISPR/Cas 系统：CRISPR1 和 CRISPR2。根据cas基因组成，CRISPR1被归类为I-E型CRISPR/Cas系统，并且具有单个阵列CRISPR1。 CRISPR2是一种I-F型系统，具有两个阵列：CRISPR2.1和CRISPR2.2。 RT-PCR 分析表明，两个系统的所有 cas 基因均在培养基中的对数生长过程中表达。 CRISPR 2.1 和 2.2 的同向重复序列是相同的，并在其他沙雷氏菌属的阵列中发现，包括粘质沙雷氏菌和方型沙雷氏菌，而 CRISPR1 则不然。我们搜索了潜在的间隔靶标，并揭示了两个系统之间的一个有趣的差异：只有 9% 的 CRISPR1（I-E 型）靶标位于噬菌体序列中，而 91% 位于质粒序列中。相反，约 66 % 的 CRISPR2（I-F 型）靶标存在于噬菌体基因组中。我们的结果强调了蚊子肠道相关细菌中 CRISPR 位点的存在，并表明了共生体与入侵性移动遗传元件在进化过程中的相互作用。
The microbiome profoundly influences many traits in medically relevant vectors such as mosquitoes, and a greater functional understanding of host–microbe interactions may be exploited for novel microbial-based approaches to control mosquito-borne disease. Here, we characterized two novel clustered regularly interspaced short palindromic repeats (CRISPR)/Cas systems in Serratia sp. Ag1, which was isolated from the gut of an Anopheles gambiae mosquito. Two distinct CRISPR/Cas systems were identified in Serratia Ag1, CRISPR1 and CRISPR2. Based on cas gene composition, CRISPR1 is classified as a type I-E CRISPR/Cas system and has a single array, CRISPR1. CRISPR2 is a type I-F system with two arrays, CRISPR2.1 and CRISPR2.2. RT-PCR analyses show that all cas genes from both systems are expressed during logarithmic growth in culture media. The direct repeat sequences of CRISPRs 2.1 and 2.2 are identical and found in the arrays of other Serratia spp., including S. marcescens and S. fonticola , whereas CRISPR1 is not. We searched for potential spacer targets and revealed an interesting difference between the two systems: only 9 % of CRISPR1 (type I-E) targets are in phage sequences and 91 % are in plasmid sequences. Conversely, ~66 % of CRISPR2 (type I-F) targets are found within phage genomes. Our results highlight the presence of CRISPR loci in gut-associated bacteria of mosquitoes and indicate interplay between symbionts and invasive mobile genetic elements over evolutionary time.