Abstract:

[Objective] This study aimed to characterize the mRNA relative expression levels of NF-κB signaling pathway associated genes in different segments of maternal and fetal gastrointestinal tracts of Mongolian horses. [Method] Three pregnant Mongolian mares in good body condition were selected and slaughtered, and the fetuses were removed during slaughter. The tissues of stomach, duodenum, jejunum, ileum, cecum, macrocolon, microcolon and rectum of the mares and fetuses were collected, and quantitative real-time PCR （qPCR） was used to analyze the mRNA relative expression levels of six genes （NF-κB p50, NF-κB p65, NFKBIA, IL-1β, TNF-α and IL-8） associated with NF-κB signaling pathway in these tissues. The expression differences of these genes in different segments of maternal and fetal gastrointestinal tracts were compared. [Result] The expressions of the six genes associated with NF-κB signaling pathway were all observed in tissues of the eight segments of maternal and fetal gastrointestinal tracts. In general, the mRNA relative expression levels of NF-κB p50, NF-κB p65 and NFKBIA genes were higher in maternal and fetal tissues, while those of IL-1β, TNF-α and IL-8 genes were lower. In tissues of the eight segments of gastrointestinal tract, the mRNA relative expression levels of the six genes associated with NF-κB signaling pathway were generally higher in mares in comparison to those in fetuses. In ileum and cecum tissues, the mRNA relative expression level of NF-κB p50 gene in mares was significantly （P<0.05） higher than that in fetuses. In macrocolon tissues, the mRNA relative expression levels of NF-κB p65 and NFKBIA genes in mares were significantly （P<0.05） higher than those in fetuses. [Conclusion] Six genes associated with NF-κB signaling pathway were all expressed in tissues of eight segments of maternal and fetal gastrointestinal tracts of Mongolian horses, and there were certain differences in expression levels. The mRNA relative expression levels of NF-κB p50, NF-κB p65 and NFKBIA genes in maternal tissues of selected intestinal segments were significantly higher than those in fetal tissues.

Key words: Mongolian horses, gastrointestinal tract, NF-κB signaling pathway, mRNA relative expression level, quantitative real-time PCR