EMERGENCE AND SCATTERING OF MULTIPLE NEUROFIBROMATOSIS (NF1)-RELATED SEQUENCES DURING HOMINOID EVOLUTION SUGGEST A PROCESS OF PERICENTROMERIC INTERCHROMOSOMAL TRANSPOSITION

Type 1 neurofibromatosis (NF1) gene encodes for a member of the GTPase activating protein family and is considered to be a tumor suppressor gene, Its very high rate of de novo mutation in humans led us to study a specific feature of this gene: the presence of numerous NF1-related sequences, According to our results, the human genome contains at lea st 11 NF1-related sequences, nine of which are scattered near centrome ric sequences of seven different chromosomes, These NF1-related sequen ces, whose extent is quite varied according to loci, are unprocessed c opies of the NF1 gene, and bear-numerous mutations, A phylogenetic ana lysis of the six largest sequences indicates that they are all derived from a common ancestor, which would have appeared 22-33 million years ago, and was subsequently duplicated several times during hominoid ev olution, The most recent duplication and interchromosomal transpositio n occurred in the last million years suggesting that the process could still be ongoing, intriguing similarities between the evolution of al pha-satellite DNA and NF1-related sequences suggest the involvement of a common genetic mechanism for the generation and pericentric spreadi ng of these NF1 partial copies.