title: Comparative sequence analysis of a single-gene conserved segment in mouse and human.
abstract: Comparative mapping and sequencing of the mouse and human genomes have defined large, conserved chromosomal segments in which gene content and order are highly conserved. These regions span megabase-sized intervals and together comprise the vast majority of both genomes. However, the evolutionary relationships among the small remaining portions of these genomes are not as well characterized. Here we describe the sequencing and annotation of a 341-kb region of mouse Chr 2 containing nine genes, including biliverdin reductase A (Blvra), and its comparison with the orthologous regions of the human and rat genomes. These analyses reveal that the known conserved synteny between mouse Chromosome (Chr) 2 and human Chr 7 reflects an interval containing one gene (Blvra/BLVRA) that is, at most, just 34 kb in the mouse genome. In the mouse, this segment is flanked proximally by genes orthologous to human chromosome 15q21 and distally by genes orthologous to human Chr 2q11. The observed differences between the human and mouse genomes likely resulted from one or more rearrangements in the rodent lineage. In addition to the resulting changes in gene order and location, these rearrangements also appear to have included genomic deletions that led to the loss of at least one gene in the rodent lineage. Finally, we also have identified a recent mouse-specific segmental duplication. These finding illustrate that small genomic regions outside the large mouse-human conserved segments can contain a single gene as well as sequences that are apparently unique to one genome.
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, 615 Michael St, Suite 301 Atlanta, Georgia 30322, USA. jthomas@genetics.emory.edu
authors.forename: James W
authors.initials: JW
authors.lastname: Thomas
authors.forename: Eric D
authors.initials: ED
authors.lastname: Green
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D002884:Chromosomes, Human, Pair 15; D017124:Conserved Sequence; D019143:Evolution, Molecular; D017353:Gene Deletion; D016678:Genome; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008957:Models, Genetic; D008969:Molecular Sequence Data; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics; D051381:Rats
chemical_list: D044925:Oxidoreductases Acting on CH-CH Group Donors; C019789:biliverdin reductase