title: Predictable transcriptome evolution in the convergent and complex bioluminescent organs of squid.
abstract: Despite contingency in life's history, the similarity of evolutionarily convergent traits may represent predictable solutions to common conditions. However, the extent to which overall gene expression levels (transcriptomes) underlying convergent traits are themselves convergent remains largely unexplored. Here, we show strong statistical support for convergent evolutionary origins and massively parallel evolution of the entire transcriptomes in symbiotic bioluminescent organs (bacterial photophores) from two divergent squid species. The gene expression similarities are so strong that regression models of one species' photophore can predict organ identity of a distantly related photophore from gene expression levels alone. Our results point to widespread parallel changes in gene expression evolution associated with convergent origins of complex organs. Therefore, predictable solutions may drive not only the evolution of novel, complex organs but also the evolution of overall gene expression levels that underlie them.
authors.affiliation: Ecology, Evolution, and Marine Biology Department, University of California, Santa Barbara, CA 93106;
authors.forename: M Sabrina
authors.initials: MS
authors.lastname: Pankey
authors.affiliation: Departments of Statistics and Biology, University of Washington, Seattle, WA 98195; and.
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Minin
authors.affiliation: Departments of Statistics and.
authors.forename: Greg C
authors.initials: GC
authors.lastname: Imholte
authors.affiliation: Departments of Biomathematics, Biostatistics, and Human Genetics, University of California, Los Angeles, CA 90095.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Suchard
authors.affiliation: Ecology, Evolution, and Marine Biology Department, University of California, Santa Barbara, CA 93106; todd.oakley@lifesci.ucsb.edu.
authors.forename: Todd H
authors.initials: TH
authors.lastname: Oakley
mesh_terms: D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D049832:Decapodiformes / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000502:physiology*; D013559:Symbiosis / Q000502:physiology*; D059467:Transcriptome / Q000502:physiology*
keywords: complexity; convergence; gene expression; novelty; parallel evolution