We employed fluorescence-activated chromosome sorting (FACS) to construct c
hromosome paint sets for the woolly monkey (Lagothrix lagotricha) and then
FISH to reciprocally paint human and woolly monkey metaphases. Reciprocal c
hromosome painting between humans and the woolly monkey allowed us to assig
n subchromosomal homologies between these species. The reciprocal painting
data between humans and the woolly monkey also allow a better interpretatio
n of the chromosomal difference between humans and platyrrhines, and refine
hypotheses about the genomic rearrangements that gave origin to the genome
of New World monkeys. Paints of woolly monkey chromosomes were used to pai
nt human metaphases and forty-five clear signals were detected. Paints spec
ific to each human chromosome were used to paint woolly monkey metaphases.
The 23 human paints gave 39 clear signals on the woolly monkey karyotype. T
he woolly monkey chromosomes painted by human paints produced 7 association
s of segments homologous to human chromosomes or human chromosome segments:
2/16, 3/21, 4/15, 5/7, 8/18, 10/16 and 14/15. A derived translocation betw
een segments homologous to human chromosomes 4 and 15 is a synapomorphic ma
rker linking all Atelines. These species may also be linked by fragmentatio
n of homologs to human 1, 4, and 15.