SP7 and infection: The expression of many genes involved in innate immunity was down regulated from 5 to 7 dpi group, and there was no significant difference compared with the NC group; By comparing the 3 dpi and 7 dpi groups, it was found that miR-429-1, miR-143-3p-1, etc. were differentially expressed in both two groups, and they mainly regulated CALCRL, MYO3B, SP7 and others, which played a role in the regulation of transcription and signal transduction, which may be related to cross-species infection of SW2783.