2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

microarray based transciptome analysis revealed unique patterns of gene expression
that may explain the fitness properties of invasive Cottus. We have used whole
genome sequencing data to study segmental mutations in the hybrid lineage after
initial hybridization. We find evidence that the genome size has increased by
approximately 10% through multiple small scale increases of copy number.
Importantly, this inflation is particularly pronounced in genes that we have identified
as candidate genes in adaptive evolution based on increased levels of gene
expression. Our study provides first evidence that mutational mechanisms that are
specifically enhanced in hybrid genomes contribute to adaptive evolution in an
emerging hybrid species.
S�25 Tereza Manousaki R 513 / 16:45
Parsing parallel evolution: ecology and transcriptomics of hyperthrophic lips in
Midas cichlid fishes
Authors: Tereza Manousaki 1 , Pincelli Hull 2 , Henrik Kusche 1 , Gonzalo Machado-
Schiaffino 1 , Paolo Franchini 1 , Chris Harrod 3 , Kathryn Elmer 1 , Axel Meyer 1
Affiliations: 1 Lehrstuhl für Zoologie und Evolutionsbiologie, Department of
Biology, University of Konstanz; 2 Department of Geology and Geophysics,
Yale University, New Haven, Connecticut; 3 Department of Evolutionary
Genetics, Max Planck Institute for Limnology, Plön
Cichlid fishes are widely known for their explosive rates of speciation and their huge
phenotypic diversity. In the great and also the crater lakes of Nicaragua,
geographically isolated populations of Midas cichlid fishes have repeatedly evolved
similar phenotypic changes in parallel. Here, we examined the repeated evolution of
hypertrophic (thick)-lips in Midas cichlid fishes to assess whether similar changes in
gene expression accompany the evolution of this parallel trait allowing them to
occupy similar, but often, not identical ecological niches. Using next-generation
sequencing technology we characterized transcriptome-wide differential gene
expression in the lips of wild-caught sympatric thick- and thin-lipped cichlids from
two great and two crater lakes. Six genes showed similar expression pattern between
the thick and thin-lipped morphs across these comparisons in all four lakes. Much
fewer genes are differentially expressed among endemic species in the younger
crater lakes than in those from the older great lakes. From a phenotypic perspective,
several traits evolved in parallel (those related to foraging ecology; e.g., lip size, body
and head shape) but others, somewhat surprisingly, do not (those related to diet and
its processing; e.g., jaw size and shape, stable isotopes). The synthesis of our
multifaceted approach reveals a somewhat unexpected mosaic pattern of parallel
and non-parallel evolution of traits. We conclude that there are multiple evolutionary
trajectories that can lead to the repeated evolution of a type of (lipped) fish that
characterizes an ecological guild.
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