Metamorphs from each of stages 36, 40, 42 and 46 were pooled and analysed for differences in adult globin mRNA between treated and untreated groups. The results indicated no significant differences in adult globin mRNA levels between treated and untreated groups at any of these 4 stages (Fig. 4a) . A p-value of 0.914 was determined using the same student t-test as for the swim speed and jump length. As pooling animals from each stage could have masked effects in individual animals, 6 animals were taken from the treated and untreated groups at stage 46 and analysed individually. Again, no significant difference in globin mRNA levels was observed between individuals from treated and control groups. A p-value of 0.095 was determined using the student t-test outlined previously. As seen for the mRNA studies, we detected no change in the protein profiles of adult globin immunised metamorphs (n = 10) compared to control (n = 9) animals by Western blot (Fig. 4b) . Similar results were recorded in preliminary trials conducted using native globin purified from the blood of adult toads rather than recombinant globin. These inoculations had no effect at the morphological or mRNA and protein levels (data not shown). We were unable to detect reactive antibodies (IgY) against recombinant globin protein in any of the animals by ELISA. However, we were also unable to detect antibody to a normally highly immunogenic test antigen (ovalbumin) in metamorphs, although reactive antibodies generated by immunising one adult with ovalbumin were readily detectable (Fig. 5 ).