Immunologic determination of the major allergen, Cry j 1, in Cryptomeria japonica pollen of 117 clones in Toyama prefecture: Some implications for further forestry research in pollinosis prevention

ABSTRACTBackgroundA number of recent studies have clarified the characteristics of major allergens of Cryptomeria japonica, such as the locality, molecular weights of Cry j 1 and Cry j 2 and cross-reactivity with some other species of pollen. However, in order to plant C. japonica forests with low allergen levels, there is still a shortage of fundamental data for forest breeding.MethodsTo obtain the some fundamental data concerning Cry j 1, three items were investigated: (i) variations in weight and Cry j 1 content per single pollen grain among 117 clones; (ii) environmental factors affecting Cry j 1 content; and (iii) genotype variations of Cry j1.ResultsAlthough the variation in weight per single pollen grain among 117 clones was relatively small (mean (±SD) 10.2 ± 0.1 ng), the Cry j 1 content was found to vary widely from 0.26 to 7.54 pg. The expression level of Cry j 1 was higher in samples collected from lower altitudes. Using western blotting, it was shown that there were two Cry j 1 genotype variations.ConclusionsFrom these results, we have concluded that immunologic determination of Cry j 1 by individual pollen grain levels provides useful data, especially for forest breeding to prevent pollinosis