The Chromosomal Organization of the Human Endogenous Retrovirus-like Sequence HERV-H: Clustering of the HERV-H Sequences in a 300-kb Region Close to the GRPR Locus on the X Chromosome
Within the haploid genome there are approximately 1,000 copies of the human endogenous retroviruslike sequence, HERV-H. Although these sequences are scattered throughout the entire genome, in situ hybridization experiments revealed that there are discrete clusters positioned on chromosomes 1p and 7q. In this study, we have located three HERV-H sequences which were unexpectedly clustered within a 300-kilobase region close to the GRPR locus on the X chromosome. In previous studies, no clusteringof this sequence has been reported at this locus. Our finding demonstrates that, like other repetitive sequences, clustering of HERV-H occurs in the human genome, although these sequences may not always be detected by in situ hybridization methods.