Human chromosomal polymorphism. VII. The distribution of chromosomal Q-polymorphic bands in different human populations.
The distribution of chromosomal Q-polymorphic bands was studied in different human populations. The populations studied showed no differences in the relative amount of Q bands in all the 12 polymorphic loci of seven autosomes, but interpopulation differences did exist in the absolute amount of Q bands in all the 12 potentially polymorphic loci of seven autosomes, these differences consisting of uniform increases or decreases in this absolute amount. Comparisons of the mean number of Q-heterochromatin bands with fluorescence levels 4 and 5 per individual showed a consistent prevalence of this quantitative parameter of chromosomal Q polymorphism in females as compared to males in all the national groups. It is suggested that there is some dosage compensation of chromosomal Q-heterochromatin material in females due to the absence of a chromosome in their genome, which is able to "compensate" for the large Q band in chromosome Y which is present only in the karyotype of males.
D000349:Africa; D001208:Asia; D044466:Asian People; D044383:Black People; D002874:Chromosome Mapping; D005260:Female; D005828:Genetics, Population; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D014586:USSR; D044465:White People