DISTRIBUTION OF ALLELIC FORMS OF ERYTHROCYTE H1 HISTONES IN JAPANESE-QUAIL POPULATIONS DIVERGENTLY SELECTED FOR AMOUNT OF WEIGHT-LOSS AFTERTRANSIENT STARVATION

Three polymorphic subtypes of erythrocyte histone H1 (H1.a, H1.b, and H1.z) were analyzed using a sodium dodecyl sulfate polyacrylamide gel in quail populations divergently selected for a high (line 1) or low ( line 2) reduction in body mass following temporary food withdrawal. Bo th H1.b and H1.z histone alleles were found to be differently distribu ted in these populations during the selection period. The frequency of b(1) in line 2 was approximately 1.9-2.8 times lower than in line 1 a nd approached the values in line 1 when the selection was suspended. S imilarly, the frequency of allele z(2) at locus H1.z increased signifi cantly (about 1.6-2.3 times) in line 2 during selection and returned t o the initial values when selection was stopped. On the other hand, al lele a(0) at locus H1.a was kept at relatively low levels (usually bel ow 0.05) in both lines during selection. As that time its level was ap proximately three to four times lower than in a random mating control population. When selection was suspended, the frequency of a(0) in lin e 1 increased significantly, approaching the values in the control lin e, and remained essentially unchanged in line 2. Thus, all three polym orphic histone H1 loci in quail responded through changes in allele fr equencies to the breeding selection, which was directed at the amount of body weight loss upon transient starvation. It seems that either H1 histone locus could be linked to loci controlling the rate of body we ight reduction following starvation or weight loss during fasting migh t be influenced by a panel of H1 histone alleles that can contribute t o functional differences in avian chromatin.