HOMOLOGIES BETWEEN HUMAN AND MARMOSET (CALLITHRIX-JACCHUS) CHROMOSOMES REVEALED BY COMPARATIVE CHROMOSOME PAINTING

Regions of DNA homology between human and marmoset (Callithrix jacchus ) chromosomes have been demonstrated using fluorescence in situ hybrid ization. All 24 chromosome paints and two centromere repeat sequences from Homo sapiens (HSA) have been annealed to previously G-banded meta phase spreads of Callithrix jacchus. All human paint probes, except Y, successfully hybridized to marmoset chromosomes. Fifteen of them hybr idized to one region only, seven to two regions, and paint 1 to three regions. Homologies proposed from previous banding comparisons have be en confirmed for HSA 2, 4-6, 10-12, 18, 19, 21, and X and partially co nfirmed for HSA 1 and 3, but were not in agreement for HSA 14 and 17. Human centromere repeat sequences for X and 18 did not hybridize to ma rmoset chromosomes. Because, at present, there is the confusing situat ion of several different numbering systems for marmoset chromosomes, w e propose a new simpler nomenclature based on descending order of chro mosome size. (C) 1996 Academic Press, Inc.