Trends in heterozygosity in the process of producing inbred strains of Japanese quail.

Trends in heterozygosity in the process of producing inbred strains of Japanese quail were examined through the characterization of protein polymorphisms based on gene freqencies of 7 polymorphic loci. The average heterozygosity (Ho) at generation 1 was 0.472 and it decreased with increasing inbreeding coefficient (F) to 0.214 at generation 5 when F was 0.594. In all generations, the observed heterozygosities of the surviving families tended to be higher than those of the families that did not survive. The frequency of heterozygotes of the Es-4 locus in surviving families was higher than that of the extinct families in each generation and the difference became conspicuous in generation 4. These results suggest that a heterozygote advantage of Es-4 locus is revealed by inbreeding.