A MODEL FOR THE PREDICTION OF RELATIVE TITERS OF AVIAN MALARIA AND ASPERGILLUS SPP IGG IN JACKASS PENGUIN (SPHENISCUS-DEMERSUS) FEMALES BASED ON MATERNAL IGG IN EGG-YOLK

Graczyk T. K. & Cranfield M. R. 1996. A model for the prediction of re lative titres of avian malaria and Aspergillus spp, IgG in Jackass pen guin (Spheniscus demersus) females based on maternal IgG in egg-yolk. International Journal for Parasitology 26: 749-754, A model for the pr ediction of IgG titres in females of the Jackass penguin (Spheniscus d emersus) was developed, based on IgG which was maternally transmitted to the yolk of unembryonated eggs produced by these females, However, prediction of the female titre based on the titre of embryonated eggs may be inadequate, Blood samples from 10 S. demersus females and their corresponding embryonated (n=10) and unembryonated (n=49) eggs were a nalysed by indirect ELISA for avian malaria(Plasmodium relictum, P. el ongatum) IgG and Aspergillus spp, IgG. There was no correlation betwee n humoral responses to avian malaria and Aspergillus spp. in females o r in their eggs. Avian malaria and Aspergillus spp, titres were signif icantly higher (P<0.05) in the eggs than in the corresponding females and were significantly correlated (P<0.01) with the blood titres, r=0. 84, r=0.89, respectively, No correlation was found between titres of e mbryo yolk-sec (embryonated eggs) and the blood of their female parent ; however, the embryo blood and the corresponding female titres were s ignificantly (P<0.05) correlated (arian malaria, r=0.74; Aspergillus s pp., r=0.69). Blood and the corresponding egg-yolk (unembryonated eggs ) IgG titres regressed significantly (P<0.01). Female IgG titre (y) is related to (unembryonated) egg-yolk IgG titre by the significant (P<0 .05) regression y=-0.61+1.46X for avian malaria, and y=-0.02+0.85X for Aspergillus spp., with +/- 95% prediction limits of +/- 0.15 and +/- 0.12, respectively, This model provides access to serological informat ion on the remote free-ranging Jackass penguins and captive Jackass-pe nguin colonies without the necessity of stressful blood collection. Co pyright (C) 1996 Australian Society for Parasitology.