Figure 2. Number of differently expressed genes in the pig categories.

Comparison of the differently expressed genes in the present study comparing neutral pigs in a tail biting pen with control pigs in a non-tail biting pen (Grey circle and box) with the gene lists from an earlier study comparing tail biters (TB), receivers (R) and neutral pigs (N) ([6], white circles and boxes). The boxes indicate the total number of differently expressed transcripts in the three comparisons. Out of these, 17 transcripts in the hypothalamus and 3 in the prefrontal cortex were differently expressed in all three comparisons, suggesting that for many of the genes, the N pigs are different from all other categories.