Maxine Merrington

The relative positions of the chromosomes in the human cell in mitosis

In a recent paper on the positions of the sex chromosomes in the human cell in mitosis ( I

DISTANCES WHICH INVOLVE SATELLITED CHROMOSOMES IN METAPHASE PREPARATIONS.

164) we gave a method of analysis depending on the counts of the chromosome centromeres lying outside a given circle. If there are N chromosomes with (si,yi) the co-ordinates of the centromere of the ith chromosome (i = 1,2, . , , N ) referred to any arbitrary pair of axes we may plot these points as a centromere diagram.

TABLES OF PERCENTAGE POINTS OF THE INVERTED BETA (F) DISTRIBUTION

Investigations of distance measurements between centromeres of human chromosomes in metaphase photographs show that there is a general tendency for homologous pairs to lie closer to one another than would be expected on the hypothesis of random arrangement. In the present analysis no significant divergence from random arrangement of their distances was found for the specific pairs nos. 1, 2 and 3. However, there is strong evidence that the groups of large and small acrocentrics tend to lie closer to one another than would be expected on the random hypothesis. The distances between no. 1 and nos. 21 or 22 chromosomes were not found to be significantly less than expected.