Seven up

In the April 10 Sciencexpress Scherer et al. report completion of the sequencing and annotation of human chromosome 7 (Sciencexpress, DOI:10.1126/science.1083423, April 10, 2003). The sequence is 158 megabases long, most of which comes from the Celera whole-genome scaffolds, combined with the publicly funded clone-based sequence. The authors integrated the chromosome 7 sequence with data from a number of database resources, particularly those related to human disease. Comparative analysis revealed a relatively small number of discrepancies with the NCBI chromosome 7 assembly. Comparison with the Celera mouse genome sequence led to the identification of around 22,000 syntenic anchor points. Scherer et al. identified 1,917 gene structures, almost half of which correspond to known genes; the average gene size is around 70 kb, and there are 99 overlapping genes and 38 sense-antisense gene pairs. There is evidence for extensive intra-chromosomal duplications, some of which coincide with mouse synteny breaks or with human diseases. Scherer et al. report that several human disorders, including susceptibility to autism and Williams-Beuren syndrome, may map to inversion breakpoints.