| Summary: | <p>Abstract</p> <p>Background</p> <p>The draft mouse (<it>Mus musculus</it>) genome sequence revealed an unexpected proliferation of gene duplicates encoding a family of secretoglobin proteins including the androgen-binding protein (ABP) α, β and γ subunits. Further investigation of 14 α-like (<it>Abpa</it>) and 13 β- or γ-like (<it>Abpbg</it>) undisrupted gene sequences revealed a rich diversity of developmental stage-, sex- and tissue-specific expression. Despite these studies, our understanding of the evolution of this gene family remains incomplete. Questions arise from imperfections in the initial mouse genome assembly and a dearth of information about the gene family structure in other rodents and mammals.</p> <p>Results</p> <p>Here, we interrogate the latest 'finished' mouse (<it>Mus musculus</it>) genome sequence assembly to show that the <it>Abp </it>gene repertoire is, in fact, twice as large as reported previously, with 30 <it>Abpa </it>and 34 <it>Abpbg </it>genes and pseudogenes. All of these have arisen since the last common ancestor with rat (<it>Rattus norvegicus</it>). We then demonstrate, by sequencing homologs from species within the <it>Mus </it>genus, that this burst of gene duplication occurred very recently, within the past seven million years. Finally, we survey <it>Abp </it>orthologs in genomes from across the mammalian clade and show that bursts of <it>Abp </it>gene duplications are not specific to the murid rodents; they also occurred recently in the lagomorph (rabbit, <it>Oryctolagus cuniculus</it>) and ruminant (cattle, <it>Bos taurus</it>) lineages, although not in other mammalian taxa.</p> <p>Conclusion</p> <p>We conclude that <it>Abp </it>genes have undergone repeated bursts of gene duplication and adaptive sequence diversification driven by these genes' participation in chemosensation and/or sexual identification.</p>
|
|---|