Simultaneous application of t -test and fold change criteria to identify acetaminophen and carbon tetrachloride affected genes in mice liver

Abstract t -Test and fold change criteria were employed simultaneously following acute exposure to acetaminophen and carbon tetrachloride to provide high statistical confidence in the identification of affected genes in mice livers. Furthermore, gene expression data was also investigated with either t -test or fold change criteria alone. Gene expression studies were also accompanied by liver histological and serum biochemical studies for toxicity evaluation. We identified a large number of affected genes using both filtering criteria ( p < 0.01 and twofold) simultaneously following both the hepatotoxicants. In some cases gene expression studies provided the earliest evidence of tissue response in the absence of traditional markers at histological and biochemical level. We conclude that simultaneous application of t -test and fold change criteria helps to identify important genes with greater statistical confidence than the use of either of them alone, however, this approach results in the reduction of identified probes. Thus, data analysis at different statistical stringencies is needed to know exact outcome of any toxicological event.