Transmission of the crinivirus, lettuce infectious yellows virus (LIYV), is determined by a minor coat protein (CPm)-mediated virion retention mechanism located in the foregut of its whitefly vector. To better understand the functions of LIYV CPm, chimeric CPm mutants engineered with different lengths of the LIYV CPm amino acid sequence and that of the crinivirus, lettuce chlorosis virus (LCV), were constructed based on bioinformatics and sequence alignment data. The 485 amino acid-long chimeric CPm of LIYV mutant, CPmP-1, contains 60 % (from position 3 to 294) of LCV CPm amino acids. The chimeric CPm of mutants CPmP-2, CPmP-3 and CPmP-4 contains 46 (position 3 to 208), 51 (position 3 to 238) and 41 % (position 261 to 442) of LCV CPm amino acids, respectively. All four mutants moved systemically, expressed the chimeric CPm and formed virus particles. However, following acquisition feeding of the virus preparations, only CPmP-1 was retained in the foreguts of a significant number of vectors and transmitted. In immuno-gold labelling transmission electron microscopy (IGL-TEM) analysis, CPmP-1 particles were distinctly labelled by antibodies directed against the LCV but not LIYV CPm. In contrast, CPmP-4 particles were not labelled by antibodies directed against the LCV or LIYV CPm, while CPmP-2 and -3 particles were weakly labelled by anti-LIYV CPm but not anti-LCV CPm antibodies. The unique antibody recognition and binding pattern of CPmP-1 was also displayed in the foreguts of whitefly vectors that fed on CPmP-1 virions. These results are consistent with the hypothesis that the chimeric CPm of CPmP-1 is incorporated into functional virions, with the LCV CPm region being potentially exposed on the surface and accessible to anti-LCV CPm antibodies.

中文翻译：

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生菜传染性黄色病毒小外壳蛋白 (CPm) 在介导粉虱载体嵌合 CPm 突变体的前肠保留和传播中的可塑性

crinivirus，生菜传染性黄色病毒 (LIYV) 的传播是由位于其粉虱载体前肠中的次要外壳蛋白 (CPm) 介导的病毒粒子保留机制决定的。为了更好地理解 LIYV CPm 的功能，基于生物信息学和序列比对数据构建了用不同长度的 LIYV CPm 氨基酸序列和 crinivirus、莴苣萎黄病毒 (LCV) 的嵌合 CPm 突变体。LIYV 突变体 CPmP-1 的 485 个氨基酸长嵌合 CPm，包含 60%（从第 3 位到 294 位）的 LCV CPm 氨基酸。突变体CPmP-2、CPmP-3和CPmP-4的嵌合CPm分别含有46个(位置3至208)、51个(位置3至238)和41％(位置261至442)的LCV CPm氨基酸。所有四个突变体系统地移动，表达嵌合 CPm 并形成病毒颗粒。然而，在获得病毒制剂后，只有 CPmP-1 保留在大量载体的前肠中并被传播。在免疫金标记透射电子显微镜 (IGL-TEM) 分析中，CPmP-1 颗粒被针对 LCV 而不是 LIYV CPm 的抗体明显标记。相比之下，CPmP-4 颗粒没有被针对 LCV 或 LIYV CPm 的抗体标记，而 CPmP-2 和 -3 颗粒被抗 LIYV CPm 弱标记，但没有被抗 LCV CPm 抗体标记。CPmP-1 的独特抗体识别和结合模式也显示在以 CPmP-1 病毒粒子为食的粉虱载体的前肠中。这些结果与 CPmP-1 的嵌合 CPm 并入功能性病毒粒子的假设一致，