Racial Differences in the Length of the Human Y Chromosome

Abstract

Variation in the length of the Y chromosome in a population of 100 males, derived from five different racial and ethnic sub-groups, was investigated. The Y chromosome and selected autosomes were measured in 1000 metaphase cells. Statistical analysis of the data demonstrates significant differences in mean length of the Y among some of the groups as well as among the individuals within each group. The mean length of the Japanese Y chromosome was significantly greater than that of all other groups. Among a sample of 736 circular metaphase plates, the Y chromosome was peripherally located in 241 cells.

C-banding in maize II. Identification of somatic chromosomes

“…A good example of chromosome polymorphism involving additional material is that provided by the human Y chromosome which has shown variability of its long arm among racial groups (Cohen et a!., 1966), which is due to differences in the length of the distal heterochromatic segment, as visualised through quinacrine fluorescence (Bobrow et aL, 1971) and Giemsa staining (Arrighi and Hsu, 1971).…”

The identification of a repeated DNA sequence involved in the karyotype polymorphism of the human Y chromosome

“…Evolutionary lability would also be indicated by racial differences, but here again the data are scarce. There is one report of Japanese having a high frequency of large Y chromosomes (Cohen et al, 1966). However, in three other species of mammals, karyotype polymorphisms for the Y chromosome have been reported (Hunger iord and Noweli., 1963;Lehman et al, 1963;Matthey, 1964).…”

“…A major class of karyotype polymorphism is the variation in length of the Y chromosome (Unnhrus et al, 1963;Cohen et al, 1966). Two hypotheses have been put forward to explain this variation: (1) there are alterations in the packing of the chromatin into the metaphase chromo some (Wennstrom and de la Chapelle, 1965), and (2) there are funda mentally different amounts of DNA in the different-sized chromosomes (Geraedts et al, 1975).…”

Peripheral location of the Y chromosome: Relationship to race and length heteromorphism

“…Such an approach has not been taken before; therefore such an impression neither can be confirmed nor denied. However, location of the Y chromosome has been observed with respect to other chromosomes and its peripheral location has been suggested by some investigators (Miller et aL, 1963;Gripenberg, 1964;Cohen et al, 1966;and Kowalski et aL, 1978) while denied by other (Spence et aL, 1973;and Sele et a!., 1977). The long arm of the Y chromosome is heterochromatic, with length heteromorphisms.…”