Convergent loss of an anciently duplicated, functionally divergent RH2 opsin gene in the fugu and Tetraodon pufferfish lineages.
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.
Neafsey
Daniel E
DE
Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA. neafsey@broad.mit.edu
Hartl
Daniel L
DL
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*
D029941:Fish Proteins; D017299:Rod Opsins; D004247:DNA