title: Convergent loss of an anciently duplicated, functionally divergent RH2 opsin gene in the fugu and Tetraodon pufferfish lineages.
abstract: We describe the complete opsin gene families from the sequenced fugu and Tetraodon pufferfish genomes. We report the convergent loss of function of an anciently duplicated, functionally divergent RH2 or "green-sensitive" opsin gene in both pufferfish lineages, designated RH2-2. In fugu, RH2-2 apparently ceased to function very recently following a transposon-induced deletion that truncated the N-terminal 115 amino acids from the translated protein. Although a lack of frameshift or nonsense mutations in the fugu RH2-2 pseudogene suggests that the gene was lost very recently in this lineage, we were unable to detect any evidence of a selective sweep associated with the fixation of the truncated allele from population data. Interspecific comparison of the remaining fugu RH2-2 coding sequence paradoxically indicates that the gene was under strong purifying selection until the truncation occurred.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA. neafsey@broad.mit.edu
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Neafsey
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Hartl
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics; D020440:Gene Duplication; D015870:Gene Expression; D014644:Genetic Variation; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017299:Rod Opsins / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D023741:Takifugu / Q000235:genetics*; D023721:Tetraodontiformes / Q000235:genetics*
chemical_list: D029941:Fish Proteins; D017299:Rod Opsins; D004247:DNA