XIA, Mingjing; FENG, Guolei; PITTMAN, Charles U; WANG, Shiao Y; Univ. Southern Mississippi, Hattiesburg; Univ. Southern Mississippi, Hattiesburg; Mississippi State Univ., Starkville; Univ. Southern Mississippi, Hattiesburg: Differences in gene expression between Gulf killifish exposed to phenanthrene and reduced phehanthrene

Polycyclic aromatic hydrocarbons (PAHs) are pollutants of concern because of their widespread occurrence and because some are mutagenic and/or carcinogenic. Chemical reduction using solvated electrons provides a rapid and cost effective method to destroy PAHs but its effectiveness as a remediation strategy is unknown because the reaction produces a complex mixture of products. The object of this study was to determine whether gene expression measurements might be useful as a way to examine the sublethal response of Gulf killifish Fundulus grandis to PAH or reduced PAH exposure. Using phenanthrene as the model PAH, a subtracted cDNA library enriched for differentially expressed genes was created. The expression level of 12 cDNAs, selected based on their apparent difference in expression by reverse Northern blots, were determined using real-time RT-PCR. The difference in expression of vitellogenin and choriogenins H and L between fish exposed to phenanthrene and reduced phenanthrene suggests that the two compounds may affect estrogenic receptors differently. Decreased transcription of housekeeping genes such as transferrin and fibronectin suggests a decrease in the overall health of exposed fish. The maintenance of trypsinogen transcription in phenanthrene exposed fish despite starvation for four days but not in starved control fish suggests that phenanthrene stimulates the olfactory-digestive axis independent of actual food consumption. Taken together, results from the present study provides support for the use of gene expression measurements as a method to better understand response mechanisms to pollutant exposure and to detect subtle differences in response to different types of pollutants.