title: Recent duplications drive rapid diversification of trypsin genes in 12 Drosophila.
abstract: Trypsin participates in many fundamental biological processes, the most notably in digesting food. The 12 species of Drosophila provide a great opportunity to analyze the duplication pattern of trypsins and their association with dietary changes. Here, we find that the trypsin family expands dramatically after speciation. The duplication events are strongly related to the host preferences, with significantly more copy numbers in species breeding on rotting fruits. Temporal analysis of the duplication events indicates that the occurrences of these events are not simultaneous, but rather correlate to the ecological change or host shift. Furthermore, we find that the specialists and generalists have different adaptive selections, which is revealed by dynamic duplication and/or deletion and relatively high Ka/Ks values on the duplicated events in specialists. Our findings suggest that the duplication of trypsin genes has played an important role in the adaption of Drosophila to the diverse ecosystems.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, School of Life Sciences, Nanjing University, 22 Hankou Rd., Nanjing 210093, China.
authors.forename: Luolan
authors.initials: L
authors.lastname: Li
authors.forename: Shabana
authors.initials: S
authors.lastname: Memon
authors.forename: Yuanchu
authors.initials: Y
authors.lastname: Fan
authors.forename: Sihai
authors.initials: S
authors.lastname: Yang
authors.forename: Shengjun
authors.initials: S
authors.lastname: Tan
mesh_terms: D000818:Animals; D004330:Drosophila / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D020440:Gene Duplication; D014644:Genetic Variation; D014357:Trypsin / Q000235:genetics*
chemical_list: D014357:Trypsin