Table 6.

Upstream regulators predicted to affect genes differentially expressed in response to time relative to parturition in the mammary gland of cows during the dry period

Upstream Regulator	Molecule Type	Activation Score	P Value of Overlap	Genes, n
β-Estradiol	chemical - endogenous mammalian	0.81	<0.0001	37
Lipopolysaccharide	chemical drug	2.57	<0.0001	36
TNF	cytokine	1.73	<0.0001	35
Dexamethasone	chemical drug	1.16	<0.0001	35
TGF-β1	growth factor	1.42	<0.0001	31

Biopsies were obtained from cows during the dry period on day −24 and −9 relative to parturition. Microarray analysis was conducted on purified RNA using Affymetrix GeneChip Bovine Genome Arrays. Genes were identified in the effect of time relative to parturition (day −9 − day −24). Differential expression was attributed to genes meeting the criteria of P ≤ 0.05 and fold-change ≥ |1.5|. Upstream regulators were identified using IPA upstream regulator function. The top 5 upstream regulators by lowest P value of overlap. z-Score of activation: IPA prediction of the relationship between experimentally observed gene expression that is either activating or inhibiting (as compiled in the Ingenuity Knowledge Base), z-score > 0 are activating, < 0 are inhibiting. Genes, the number of differentially expressed genes predicted to be affected by upstream regulator.