Abstract：
Adenosine Deaminases Acting on RNA (ADARs) are evolutionarily conserved enzymes known to convert adenosine to inosine in double-stranded RNAs and participate in host-virus interactions. Conducting a meta-analysis of available transcriptome data, we identified and characterised eight ADAR transcripts in Chlamys farreri, a farmed marine scallop susceptible to Acute viral necrosis virus (AVNV) infections and mortality outbreaks. Accordingly, we identified six ADAR genes in the Zhikong scallop genome, revised previous gene annotations, and traced alternative splicing variants. In detail, each ADAR gene encodes a unique combination of functional domains, always including the Adenosine deaminase domain, RNA binding domains and, in one case, two copies of a Z-DNA binding domain. After phylogenetic analysis, five C. farreri ADARs clustered in the ADAR1 clade along with sequences from diverse animal phyla. Gene expression analysis indicated CF051320 as the most expressed ADAR, especially in the eye and male gonad. The other four ADAR1 genes and one ADAR2 gene exhibited variable expression levels, with CF105370 and CF051320 significantly increasing during early scallop development. ADAR-mediated single-base editing, evaluated across adult C. farreri tissues and developmental stages, was mainly detectable in intergenic regions (83 % and 85 %, respectively). Overall, the expression patterns of the six ADAR genes together with the editing and hyper-editing values computed on scallops RNA-seq samples support the adaptive value of ADAR1-mediated editing, particularly in the pre-settling larval stages.
摘要：
作用于RNA的腺苷脱氨酶(ADAR)是已知将双链RNA中的腺苷转化为肌苷并参与宿主-病毒相互作用的进化上保守的酶。对可用的转录组数据进行荟萃分析，我们鉴定并鉴定了Chlamysfarreri中的八个ADAR转录本，养殖的海洋扇贝易受急性病毒性坏死病毒（AVNV）感染和死亡暴发的影响。因此，我们在知孔扇贝基因组中鉴定出6个ADAR基因,修改了以前的基因注释，并追踪可变剪接变体。详细来说,每个ADAR基因编码一个独特的功能域组合，总是包括腺苷脱氨酶结构域，RNA结合域和,在一个案例中,Z-DNA结合结构域的两个拷贝。经过系统发育分析,在ADAR1进化枝中聚集了5个FarreriADAR，以及来自不同动物门的序列。基因表达分析显示CF051320是表达最多的ADAR，尤其是眼睛和男性性腺.另外4个ADAR1基因和1个ADAR2基因表现出不同的表达水平,CF105370和CF051320在扇贝发育早期显著增加。ADAR介导的单碱基编辑，在成虫C.Farreri组织和发育阶段进行评估，主要在基因间区域检测到(83%和85%，分别)。总的来说,六个ADAR基因的表达模式以及在扇贝RNA-seq样本上计算的编辑和超编辑值支持ADAR1介导的编辑的适应性值，特别是在沉降前的幼虫阶段。
