Abstract：This experiment was conducted to study the effect bovine lactoferrin (bLF) on antimicrobial peptide PMAP-37 gene expression. In vivo, seventy-two Duroc × Landrace × TaiHu weaning piglets (♂ Duroc× ♀Landrace× TaiHu) of 36 days were divided into three treatment groups randomly by weight and each group included three repeats of eight piglets. The control (treatment 1) received the basal dietary without bLF. Treatment 2, treatment 3 received dietary contained 0.125% bLF and 0.25% bLF respectively. In vitro, we separated bone marrow cells and cultured with bLF with 10, 100, and 1000 µg/ml respectively for 3h and 6h, and each treatment repeated three times. The control wells were incubated with culture medium. The primers for PMAP-37 and 18S rRNA were designed respectively according to the reported porcine antimicrobial peptide PMAP-37 gene and housekeeping gene 18S rRNA sequences, the suitable MgCl2 concentration and cycles in PCR system were discussed. So an optimized semi-quantitative RT-PCR was constructed, 18S rRNA used as inner control, to detect effect of different concentration bLF on antimicrobial peptide PMAP-37 gene expression in diet and in bone marrow cells of pigs. The results indicated that, compared with control group, 0.125% bLF and 0.25% bLF in diet increased the gene expression of antimicrobial peptide PMAP-37 by 109.62% (P<0.01) and 69.23% (P<0.05) respectively. In bone marrow cells, 10, 100, and 1000 µg/ml bLF also increased gene expression of PMAP-37 respectively for 3h and 6h, but statistic result was not significant. These observations suggest that antimicrobial peptide PMAP-37 gene expression could be regulated by bLF.
