Exploring the Differential Expression of a Set of Key Genes Involved in the Regulation and Functioning of the Stomach in the Post-Weaned Pig

Abstract

Despite playing a key role in digestion, there is only a broad characterization of the spatiotemporal development of the three glandular regions of the stomach (cardiac, fundic and pyloric) in the weaned pig. Hence, the objective of this experiment was to explore the differential expression (DE) of a panel of key genes within the three glandular regions of the stomach. Eight pigs were sacrificed at d 8 post-weaning, and three mucosal samples were collected from each stomach's glandular regions. The expression of a panel of genes were measured using QPCR. The true cardiac gland region was characterized by increased expression of PIGR, OLFM4, CXCL8 and MUC2 relative to the two other regions (p < 0.05). The fundic gland region was characterized by increased expression of ATP4A, CLIC6, KCNQ1, HRH2, AQP4, HDC, CCKBR, CHIA, PGA5, GHRL and MBOAT4 compared to the two other regions (p < 0.05). The pyloric gland region was characterized by exclusive expression of GAST (p < 0.05). A transition region between the cardiac and fundic region (cardiac-to-oxyntic transition) was observed with a gene expression signature that resembles a cross of the signatures found in the two regions. In conclusion, unique gene expression signatures were identifiable in each of the glandular regions, with a cardiac-to-oxyntic transition region clearly identifiable in the post-weaned pigs' stomachs.

Keywords: acid secretion; cardiac gland region; cardiac-to-oxyntic transition; fundic gland region; glandular regions; monogastric; pyloric gland region.

Figure 1

Labelled image of the pig’s stomach exposed along the greater curvature of the stomach. Mucosal sampling sites (1–9) are highlighted.

Figure 2

Correlogram representing Pearson correlations ordered by loadings to the first principal component in the cardiac gland region (sample locations 1, 2 and 3). Level of significance indicated by asterisks (* p = 0.05, ** p = 0.01, *** p = 0.001).

Figure 3

Correlogram representing Pearson correlations ordered by loadings to the first principal component in the fundic gland region (sample locations 4, 5 and 6). Level of significance indicated by asterisks (* p = 0.05, ** p = 0.01, *** p = 0.001).

Figure 4

Correlogram representing Pearson correlations ordered by loadings to the first principal component matrix for gene expression in the pyloric gland region (sample locations 7, 8 and 9). Level of significance indicated by asterisks (* p = 0.05, ** p = 0.01, *** p = 0.001).

Figure 5

The approximate location of the cardiac-to-oxyntic transition. Mucosal sampling sites (1–9) are highlighted.