鸭瘟病毒(duck plague virus，DPV)是α-疱疹病毒的重要成员，可引发鸭瘟(duck plague，DP)，严重威胁水禽业。DPV UL54基因编码蛋白具有核质穿梭特性，影响病毒复制过程，但是其在进化过程中的作用尚不明确。本研究从进化角度出发，探究DPV UL54基因编码蛋白的核质穿梭特性。首先采用分子进化学方法对DPV全基因组及UL54基因进行共进化分析；接着，构建来自不同病毒源头的UL54基因的核苷酸和氨基酸系统进化树；然后，选取与DPV距离较近的病毒毒株和DPV进行UL54基因序列比对，发现DPV UL54基因具有特异性的突变位点；最后，构建UL54基因突变重组质粒，检测这些突变位点对其编码蛋白核质穿梭特性的影响。研究结果显示，在进化过程中DPV展现出与宿主共同进化以及跨越宿主传播的双重模式，同时源自不同病毒毒株的UL54基因呈现出显著的进化差异。进一步研究发现，UL54的氨基酸位点中具有与DPV进化关联的特定突变位点，即269位的赖氨酸(Lys)、348位的亮氨酸(Leu)和377位的亮氨酸(Leu)，这些位点的变异对UL54基因编码蛋白的核质穿梭特性具有显著影响。本研究结果为理解DPV的进化机制和开发新的治疗策略提供了重要理论依据。

Duck plague virus (DPV), a member of the alpha-herpesvirus, causes duck plague (DP), thereby posing a serious threat to the waterfowl industry. The DPV UL54-encoded protein shuttles between the nucleus and cytoplasm to modulate viral replication. However, the role of the UL54 protein in the evolutionary process remains unknown. This study is conducted from an evolutionary perspective to explore the nuclear-cytoplasmic shuttling characteristic of UL54 protein. First, we analyzed the co-evolution on DPV whole genome and its UL54 gene using molecular evolutionary methods. Next, we constructed phylogenetic trees based on UL54 nucleotide sequences and the corresponding amino-acid sequences from different alpha-herpesvirus stains. Based on these phylogenetic trees, we selected strains that are genetically close to DPV, and performed UL54 gene sequence alignment between DPV and those phylogenetically related strains. Then, we discovered there were specific mutation sites in UL54 gene of DPV. Finally, we constructed recombinant plasmids with genetic mutations to detect the influence of mutation sites on the nuclear-cytoplasmic shuttling property of the UL54-encoded proteins. The results showed that DPV exhibited dual modes comprising co-evolution with its natural hosts and cross-species transmission, meanwhile UL54 genes from different viral strains exhibited marked evolutionary divergence. Further investigation revealed there were three specific mutation sites (Lys269, Leu348 and Leu377) in UL54 amino acid sites, which were correlated with evolution of DPV. Mutation at these sites significantly impacted the nuclear-cytoplasmic shuttling property of the UL54-encoded protein. Our study provides a rationale for understanding the evolutionary mechanism of DPV and exploring new therapeutic strategy.