PARENT SESSION
PT2 - Endocrine Disruption
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P554) Reproductive and Immunological Endpoints in Zebra Finches Dosed With 4-Nonylphenol.
Birmingham, Erinn*,1,2, Williams, Tony2, Elliott, John3, Ikonomou, Michael4, 1 BBL Sciences, Long Beach, CA, USA2 Simon Fraser University, Burnaby, BC, Canada3 Canadian Wildlife Service, Delta, BC, Canada4 Regional Contaminants Lab, Fisheries and Oceans Canada, Sidney, BC, Canada
ABSTRACT- Little is known about the potential for weak xenoestrogens such as 4-nonylphenol to affect avian species. We studied immunological and reproductive endpoints in captive male and female Zebra Finches (Taeniopygia guttata) dosed with 4-nonylphenol. Male birds received 21 doses (target dose: 1 
g/g or 100 g/g body weight) of 4-nonylphenol in the diet over 61 days. Male finches exhibited no definitive changes in testis histology, white blood cell profiles, skin response to phytohaemagglutinin (PHA), or organ masses. In a breeding experiment, female Zebra Finches received intramuscular injections of 4-nonylphenol (target dose: 100 g/g body weight) from the day of pairing with untreated males through laying of the fourth egg (4-6 injections total). We predicted that nonylphenol would be present in the females from ovulation through rapid yolk development for each egg (mean clutch size of 6-7 eggs), and that nonylphenol therefore would be available to affect adult females directly or partition to egg yolks and expose the embryos. Nonylphenol-injected females laid 5% heavier eggs than in previous (non-manipulated) breeding trials and 5% heavier eggs than control females in this experiment. Nonylphenol injection did not affect females' propensity to lay, pre-laying interval, egg mass, clutch size, hatching success, fledging success, or offspring sex ratio. Future analysis will examine functional fertility of offspring from nonylphenol females. As the fitness correlations of heavier eggs are unclear, these experiments did not definitively link nonylphenol exposure with detrimental reproductive or immunological effects in Zebra Finches.
Key words: nonylphenol, estrogen, endocrine disruption, Zebra Finch