W3 PM Biomarkers
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in Ballroom 3

(LOH-1117-853526) Assessment of CYP1A status of field collected tree swallows (Tachycineta bicolor) by feather immunohistochemistry.

Lohnes, K^{1, 2}, Melancon, M¹, Custer, C³, Ottinger, M², ¹ USGS Patuxent Wildlife Research Center, Beltsville, MD, USA² University of Maryland, College Park, MD, USA³ USGS Upper Midwest Environmental Sciences Center, La Crosse, WI, USA

ABSTRACT- Previously we have demonstrated CYP1A induction immunohistologically in skin of dosed tree swallows and lesser scaup(Aythya affinis)(SETAC 21st Annual Meeting, 2000) and in feathers of dosed mallard (Anas platyrhynchos)and black ducks (Anas rubripes) (SETAC 23rd Annual Meeting, 2002). More recently we have collected feathers of nestling tree swallows from areas of differing levels of contaminants that are inducers of CYP1A. Sections of these feathers were examined by immunhistochemistry using an antibody generated in rabbit to the primary CYP1A generated by BNF treatment of mallard ducks and the procedures used in the above-mentioned studies. This demonstrated the presence of CYP1A in the feathers from all nine birds collected from a highly contaminated area (3 very strongly staining, 4 with moderate staining and 2 with minimal staining). Staining for CYP1A occurred in feathers from only 1 of 14 birds from areas of low contamination and did not occur in feathers from 2 birds collected from a clean area. Presently additional feather samples collected from birds in a clean area and areas of lower contamination are being examined. Results from the feather immunohistochemistry will be compared to sediment and carcass contaminant concentrations and to hepatic microsomal O-dealkylase assays and western blotting of microsomes using the same antibody.

Key words: CYP1A, tree swallow, immunohistochemistry, biomarker