The measure of similarity between G-banded karyotypes

SUMMARY

A similarity index to quantify comparisons between G-banded karyotypes is presented. The method comprises the following steps: a) standarization of the number and location of bands in each chromosome; b) matching of similar chromosomes and comparison of band sequences between them; c) counting of similar and different bands; d) use of the following index: 10/n called standarized band similarity index (Sbs). Where Σt is the total number of bands computed (different plus similar), Σd is the number of bands which are different and n is the highest haploid value recorded among all the karyotypes compared. The banded karyotypes of several species of the genus Rattus, the family Bovidae and several genera of cricetine rodents were used to test the Sbs index.