Cagliani Rachele, Forni Diego, Mozzi Alessandra, Sironi Manuela
Scientific Institute, IRCCS E. MEDEA, Bioinformatics, 23842 Bosisio Parini, Italy.
Microorganisms. 2020 Apr 25;8(5):624. doi: 10.3390/microorganisms8050624.
Cytomegaloviruses (CMVs) infect many mammals, including humans and non-human primates (NHPs). Human cytomegalovirus (HCMV) is an important opportunistic pathogen among immunocompromised patients and represents the most common infectious cause of birth defects. HCMV possesses a large genome and very high genetic diversity. NHP-infecting CMVs share with HCMV a similar genomic organization and coding content, as well as the course of viral infection. Recent technological advances have allowed the sequencing of several HCMV strains from clinical samples and provided insight into the diversity of NHP-infecting CMVs. The emerging picture indicates that, with the exclusion of genes (genes that have orthologs in all herpesviruses), CMV genomes are relatively plastic and diverse in terms of gene content, both at the inter- and at the intra-species level. Such variability most likely underlies the strict species-specificity of these viruses, as well as their ability to persist lifelong and with relatively little damage to their hosts. However, genes, despite their strong conservation, also represented a target of adaptive evolution and subtle changes in their coding sequence contributed to CMV adaptation to different hosts. Indubitably, important knowledge gaps remain, the most relevant of which concerns the role of viral genetics in HCMV-associated human disease.
巨细胞病毒（CMV）感染包括人类和非人灵长类动物（NHP）在内的许多哺乳动物。人巨细胞病毒（HCMV）是免疫功能低下患者中的一种重要机会性病原体，也是出生缺陷最常见的感染原因。HCMV拥有庞大的基因组和非常高的遗传多样性。感染NHP的CMV与HCMV具有相似的基因组组织和编码内容，以及病毒感染过程。最近的技术进步使得能够对临床样本中的几种HCMV毒株进行测序，并深入了解感染NHP的CMV的多样性。新出现的情况表明，除了 基因（在所有疱疹病毒中都有直系同源物的基因）外，CMV基因组在基因含量方面在种间和种内水平上都相对具有可塑性和多样性。这种变异性很可能是这些病毒严格的物种特异性的基础，以及它们终身持续存在且对宿主造成相对较小损害的能力的基础。然而， 基因尽管具有很强的保守性，但也是适应性进化的目标，其编码序列的细微变化有助于CMV适应不同宿主。毫无疑问，仍然存在重要的知识空白，其中最相关的是病毒遗传学在HCMV相关人类疾病中的作用。
