你好请帮我修改以下语句中的语法错误并进行适当优化Porcine enterovirus G EV-G is a member of the Enterovirus genus of the Picornaviridae family of small RNA viruses EV-G usually has no clinical manifestations when infecting pig

Porcine enterovirus G (EV-G) belongs to the Enterovirus genus of the Picornaviridae family of small RNA viruses. While EV-G typically does not cause clinical symptoms in pigs, it is often associated with diarrhea when mixed with other GI viruses. In recent years, natural recombination of EV-G with the PLP gene has been observed in various countries. This study aimed to prepare specific antibodies for porcine enterovirus G by performing prokaryotic expression of 3C protein and preparing polyclonal antibodies to 3C protein. Additionally, the study investigated the ability of the EV-G-PLP strain to infect mice using ICR mammary mice for animal experiments.

1. Prokaryotic expression of porcine enterovirus type G 3C protein and preparation of polyclonal antibodies To prepare polyclonal antibodies to EV-G non-structural protein 3C, the researchers constructed the recombinant plasmid pET-32a-EV-G-3C and transformed it into BL21 (DE3) cells. They screened for the optimal induction conditions (induction temperature, IPTG concentration, and induction time) to obtain the best conditions for 3C protein recombination. The purified 3C protein was then immunized by subcutaneous injection into New Zealand rabbits to prepare polyclonal antibodies to 3C protein. The potency was determined using indirect ELISA, and the specificity was identified using indirect immunofluorescence assay and Western-blot. The results showed that the expressed 3C protein was mainly in the form of inclusion bodies with a relative molecular mass of about 38.8 ku and had reactivity. This study provides a reference for the diagnosis of EV-G and the biological function of 3C protein.

2. Investigation of the ability of EV-G-PLP to infect mice To investigate the susceptibility of the EV-G-PLP strain to mice, the researchers orally administered CH/20GXNN/2020/PLP virus solution to SPF grade 3-day-old ICR suckling mice. The suckling mice were executed and dissected on days 1, 3, 5, and 7 after the attack. RT-PCR identified that the EV-G-PLP strain was able to infect the suckling rats. The viral load of EV-G-PLP was detected in both intestinal and brain tissues using qRT-PCR, with little difference, and the overall comparison was intestinal > brain. The infected tissues were ground into tissue fluid and infected with Marc-145 cells, and the results showed that the intestinal and brain tissue fluids could cause cytopathic lesions. Indirect immunofluorescence identification further clarified that the cytopathic lesions were caused by the EV-G-PLP virus. This study provides a preliminary investigation of the EV-G-PLP mouse infection model and lays the foundation for the construction of an EV-G-PLP animal infection model