Size variability of the Y chromosome distal C-band in Brazilian Indians and Caucasoids

Abstract
Densitometric measurements of the Y chromosome distal heterochromatin were performed on 183 Indians and 21 Caucasoids living in Brazil. No significant intratribal intervillage variation was observed. The tribal averages ranged from 0.81-1.32 .mu.. The Caucasoid mean presented an intermediate value. Wide intrapopulation variability occurs. Bimodality in the measurements obtained among the Indians of the Amazon region is suggested. A positive correlation was found between this variable and the C-band size of chromosome 16 and between it and the heteromorphism index of chromosome 1.