Development of an Immunoassay to Detect Leptin, a Hormone Associated to Fat Metabolism, in American black bears

Poster Presentations

Determining body condition in the American black bear (Ursus americanus) is challenging due to their physiological strategies such as hibernation. Interestingly, the hormone leptin, which is highly associated to fat metabolism, is indicative of body condition and adiposity (body fat stores) in black bears. An immunoassay technique measuring leptin in serum samples was previously employed in black bears. Individuals with higher body fat content exhibit greater concentrations of serum leptin. However, the commercial form of this technique, referenced by previous work, is no longer available for bears (i.e. the manufacturer no longer produces it), and other commercially available leptin assays designed for humans, dogs, pigs, or multispecies have produced subpar results for black bears. Therefore, we aim to develop and validate a double-antibody enzyme-linked immunosorbent assay (ELISA) to measure serum leptin in black bears. We have identified an antibody with characteristics that increases our changes to bind bear leptin. Checkerboard titration tests to optimize immunoassay dynamics are underway, and lastly, we will perform immunoassay validation (parallelism tests and accuracy recovery checks) for bear serum. Our ultimate goal is to use this ELISA to assess how changes in the environment influence maternal and litter aspects related to age, body condition, date of parturition, litter size, and cub growth rates, as possible factors influencing black bear reproductive parameters in the Eastern United States.