DISTRIBUTION OF OLFACTORY RECEPTOR GENES IN THE HUMAN GENOME

We demonstrate that members of the olfactory receptor (OR) gene family are distributed on all but a few human chromosomes. Through FISH anal ysis, we show that OR sequences reside at move than 25 locations in th e human genome. Their distribution is biased for terminal bands. Flow- sorted chromosomes were used to isolate 87 OR sequences derived from 1 6 chromosomes. Their sequence-relationships are indicative of the inte r- and intrachromosomal duplications responsible for OR family expansi on. The human genome has accumulated a striking number of dysfunctiona l copies: 72% of the sequences are pseudogenes. ORF-containing sequenc es predominate on chromosomes 7, 16 and 17.