Dataset Information

Adaptive Diversification of the Lateral Line System during Cichlid Fish Radiation.

ABSTRACT: The mechanosensory lateral line system is used by fishes to sense hydrodynamic stimuli in their environment. It provides information about flow regimes, proximity to substrate, and the presence and identity of prey and predators and represents a means of receiving communication signals from other fish. Thus we may expect lateral line system structures to be under strong divergent selection during adaptive radiation. Here, we used X-ray micro-computed tomography scans to quantify variation in cranial lateral line canal morphology within the adaptive radiation of Lake Malawi cichlids. We report that cranial lateral line canal morphology is strongly correlated with diet and other aspects of craniofacial morphology, including the shape of oral jaws. These results indicate an adaptive role for the lateral line system in prey detection and suggest that diversification of this system has taken an important role in the spectacular evolution of Lake Malawi's cichlid fish diversity.

SUBMITTER: Edgley DE

PROVIDER: S-EPMC6542376 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Adaptive Diversification of the Lateral Line System during Cichlid Fish Radiation.

Edgley Duncan E DE Genner Martin J MJ

iScience 20190516

The mechanosensory lateral line system is used by fishes to sense hydrodynamic stimuli in their environment. It provides information about flow regimes, proximity to substrate, and the presence and identity of prey and predators and represents a means of receiving communication signals from other fish. Thus we may expect lateral line system structures to be under strong divergent selection during adaptive radiation. Here, we used X-ray micro-computed tomography scans to quantify variation in cra ...[more]

PMID: 31146127

Similar Datasets

Project description:The African cichlid fish radiations are the most diverse extant animal radiations and provide a unique system to test predictions of speciation and adaptive radiation theory. The past few years have seen major advances in the phylogenetics, evolutionary biogeography and ecology of cichlid fish. Most of this work has concentrated on the most diverse radiations. Unfortunately, a large number of small radiations and 'non-radiations' have been overlooked, potentially limiting the contribution of the cichlid system to our understanding of speciation and adaptive radiation. I have reviewed the literature to identify 33 intralacustrine radiations and 76 failed radiations. For as many as possible I collected information on lake size, age and phylogenetic relationships. I use these data to address two questions: (i) whether the rate of speciation and the resulting species richness are related to temporal and spatial variation in ecological opportunity and (ii) whether the likelihood of undergoing adaptive radiation is similar for different African cichlid lineages. The former is a key prediction of the ecological theory of adaptive radiation that has been presumed true but remains untested for cichlid radiations. The second is based on the hypothesis that the propensity of cichlids to radiate is due to a key evolutionary innovation shared by all African cichlids. The evidence suggests that speciation rate declines through time as niches get filled up during adaptive radiation: young radiations and early stages of old radiations are characterized by high rates of speciation, whereas at least 0.5 Myr into a radiation speciation becomes a lot less frequent. The number of species in cichlid radiations increases with lake size, supporting the prediction that species diversity increases with habitat heterogeneity, but also with opportunity for isolation by distance. Finally, the data suggest that the propensity to radiate within lakes is a derived property that evolved during the evolutionary history of some African cichlids, and the appearance of which does not coincide with the appearance of proposed key innovations in morphology and life history.

Project description:BackgroundGene duplication is a source of evolutionary innovation and can contribute to the divergence of lineages; however, the relative importance of this process remains to be determined. The explosive divergence of the African cichlid adaptive radiations provides both a model for studying the general role of gene duplication in the divergence of lineages and also an exciting foray into the identification of genomic features that underlie the dramatic phenotypic and ecological diversification in this particular lineage. We present the first genome-wide study of gene duplication in African cichlid fishes, identifying gene duplicates in three species belonging to the Lake Malawi adaptive radiation (Metriaclima estherae, Protomelas similis, Rhamphochromis "chilingali") and one closely related species from a non-radiated riverine lineage (Astatotilapia tweddlei).ResultsUsing Astatotilapia burtoni as reference, microarray comparative genomic hybridization analysis of 5689 genes reveals 134 duplicated genes among the four cichlid species tested. Between 51 and 55 genes were identified as duplicated in each of the three species from the Lake Malawi radiation, representing a 38%-49% increase in number of duplicated genes relative to the non-radiated lineage (37 genes). Duplicated genes include several that are involved in immune response, ATP metabolism and detoxification.ConclusionsThese results contribute to our understanding of the abundance and type of gene duplicates present in cichlid fish lineages. The duplicated genes identified in this study provide candidates for the analysis of functional relevance with regard to phenotype and divergence. Comparative sequence analysis of gene duplicates can address the role of positive selection and adaptive evolution by gene duplication, while further study across the phylogenetic range of cichlid radiations (and more generally in other adaptive radiations) will determine whether the patterns of gene duplication seen in this study consistently accompany rapid radiation.

Dataset Information

Adaptive Diversification of the Lateral Line System during Cichlid Fish Radiation.

Publications

Adaptive Diversification of the Lateral Line System during Cichlid Fish Radiation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets