Meeting Abstract

68.2  Sunday, Jan. 6  Seasonal fluctuations in natural and adaptive antibodies to ovalbumin in the desert tortoise (Gopherus agassizii) SANDMEIER, F.C.*; TRACY, C.R.; HUNTER, K.; DUPRE, S.; University of Nevada, Reno; University of Nevada, Reno; University of Nevada, Reno; University of Nevada, Reno fran@biodiversity.unr.edu

To assess possible effects of season, gender, and time of immunization on the humoral immune response of desert tortoises (Gopherus agassizii), 16 desert tortoises were immunized with ovalbumin (OVA) from domestic chickens prepared in Ribi�s adjuvant. OVA-specific antibodies were monitored over the course of a year in the blood of the tortoises using a Western blot technology. Unexpectedly, tortoises had two forms of antibodies to the OVA: natural OVA-specific antibodies, and antibodies produced as part of an adaptive immune response in reaction to the experimental immunization. We were able to quantify seasonal fluctuations in both natural and adaptive antibodies in male and female desert tortoises. We speculate that natural antibodies are an important line of defense for these reptiles with a slow metabolic rate that could be overwhelmed by an aggressive pathogen. We will discuss ideas about relative importance of natural and adaptive antibodies in vertebrates generally.