We investigated temporal trends of codon usage changes for different host species to determine their importance in Zika virus (ZIKV) evolution. Viral spillover resulting from the potential of codon adaptation to host genome was also assessed for the African genotype ZIKV in comparison to the Asian genotype. To improve our understanding on its zoonotic maintenance, we evaluated in vitro the biological properties of the African genotype ZIKV in vertebrate and mosquito cell lines. Analyses were performed in comparison to Yellow fever virus (YFV). Despite significantly lower codon adaptation index trends than YFV, ZIKV showed evident codon adaptation to vertebrate hosts, particularly for the green African monkey Chlorocebus aethiops. PCA and CAI analyses at the individual ZIKV gene level for both human and Aedes aegypti indicated a clear distinction between the two genotypes. African ZIKV isolates showed higher virulence in mosquito cells than in vertebrate cells. Their higher replication in mosquito cells than African YFV confirmed the role of mosquitoes in the natural maintenance of the African genotype ZIKV. An analysis of individual strain growth characteristics indicated that the widely used reference strain MR766 replicates poorly in comparison to African ZIKV isolates. The recombinant African Zika virus strain ArD128000*^E/NS5 may be a good model to include in studies on the mechanism of host tropism, as it cannot replicate in the tested vertebrate cell line.

中文翻译：

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非洲基因型寨卡病毒的生物学特征和密码子使用演化的模式。

我们调查了不同宿主物种的密码子使用变化的时空趋势，以确定它们在寨卡病毒（ZIKV）进化中的重要性。与亚洲基因型相比，非洲基因型ZIKV的密码子适应宿主基因组的潜力也导致病毒溢出。为了增进我们对其人畜共患病维护的了解，我们在体外评估了非洲基因型ZIKV在脊椎动物和蚊子细胞系中的生物学特性。与黄热病病毒（YFV）进行了比较。尽管密码子适应指数趋势明显低于YFV，但ZIKV仍显示出明显的密码子适应脊椎动物宿主，特别是绿色非洲猴Chlorocebus aethiops。在个人ZIKV基因水平上对人和人的PCA和CAI分析埃及伊蚊表明两种基因型之间有明显区别。非洲ZIKV分离株在蚊子细胞中显示出比在脊椎动物细胞中更高的毒力。它们在蚊子细胞中的复制率高于非洲YFV，这证明了蚊子在非洲基因型ZIKV的自然维持中的作用。对单个菌株生长特征的分析表明，与非洲ZIKV分离株相比，广泛使用的参考菌株MR766复制性差。重组非洲Zika病毒株ArD128000 * ^{E / NS5}可能是纳入宿主嗜性机制研究的一个很好的模型，因为它不能在测试的脊椎动物细胞系中复制。