MYD88 plays an important role in the immune response against infections. To analyze MYD88 gene expression during different stages of pig development, we used real-time PCR. MYD88 was seen expressed in all tissues examined. MYD88 expression in spleen, lungs, and thymus reached its highest value from 7 to 14 days of age and decreased thereafter. Expression in lymph nodes was high until 28 days of age and then it declined after weaning, with stable low levels in adult pigs. MYD88 expression was high before 35 days of age in the small intestine (duodenum, jejunum, and ileum), where it reached its highest value from 7 to 14 days of age. MYD88 expression in the small intestine declined post-weaning and remained relatively low during adulthood. The results of this study suggest that weaning stress and development of the immune system might be positively correlated with MYD88 expression regulation. Moreover, this study provided evidence that the high expression of MYD88 may diminish weaning stress and increase disease resistance in Meishan pigs.

Glycosphingolipid biosynthesis-globo series pathway genes (FUT1, FUT2, ST3GAL1, HEXA, HEXB, B3GALNT1, and NAGA) play an important regulatory role in the defense against Escherichia coli F18 in piglets. In this study, we identified the transcription initiation site and promoter of this gene cluster by mined previous RNA-seq results using bioinformatics tools. The FUT1 transcription initiation region included five alternative splicing sites and two promoter regions, whereas each of the six other genes had one promoter. Dual luciferase reporter results revealed significantly higher transcriptional activity by FUT1 promoter 2, indicating that it played a more important role in transcription. The promoters of glycosphingolipid biosynthesis genes identified contained a CpG island within the first 500 bp, except for the B3GALNT1 promoter which included fewer CpG sites. These results provide a deeper insight into methylation and the regulatory mechanisms of glycosphingolipid biosynthesis-globo series pathway genes in piglets.

The aim was to explore the feasibility of using bamboo vinegar powder as an antibiotics substitute in weaning piglets. Forty-five healthy Duroc × Landrance × Yorshire piglets (weight 6.74 ± 0.17 kg; age 31 days) were randomly divided into the control group (basic diet), ANT group (basic diet + 0.12% compound antibiotics), BV1 group (basic diet + 0.1% bamboo vinegar powder), BV5 group (basic diet + 0.5% bamboo vinegar powder) and BV10 group (basic diet + 1% bamboo vinegar powder). MyD88 and CD14 expression in immune tissues was examined using real-time PCR. MyD88 expression in the control group were significantly lower than that in other groups in all tissues (p<0.05), while CD14 expression showed the opposite trend. MyD88 expression was significantly higher in the BV10 group than in other groups in lung tissue (P<0.05), significantly higher in the ANT group than in the BV1 group in the kidneys (P<0.05), significantly higher in the BV10 group than in the BV1 group in the thymus (P<0.05), and significantly higher in the BV1 group than in the BV10 group in the lymphatic tissue (P<0.05). These differences between experimental groups were not observed for the CD14 gene (P>0.05). Thus, adding bamboo vinegar powder to the basic diet of weaning piglets had immune effects similar to antibiotics and the effect was dose-dependent. Moreover, the MyD88 and CD14 genes appear to play a role in these immune effects.

No abstract