Candidate genes for migration do not distinguish migratory and non-migratory birds

Abstract

Migratory traits in birds have been shown to have a strong heritable component and several candidate genes have been suggested to control these migratory traits. To investigate if the genetic makeup of one or a set of these candidate genes can be used to identify a general pattern between migratory and non-migratory birds, we extracted genomic sequence data for 25 hypothesised candidate genes for migration from 70 available genomes across all orders of Aves and characterised sequence divergence between migratory and non-migratory phenotypes. When examining each gene separately across all species, we did not identify any genetic variants in candidate genes that distinguished migrants from non-migrants; any resulting pattern was driven by the phylogenetic signal. This was true for each gene analysed independently, but also for concatenated sequence alignments of all candidate genes combined. We also attempted to distinguish between migrant and non-migrants using structural features at four candidate genes that have previously been reported to show associated with migratory behaviour but did not pick up a signal for migratory phenotype here either. Finally, a screen for dN/dS ratio across all focal candidate genes to probe for putative features of selection did not uncover a pattern, though this might not be expected given the broad phylogenetic scale used here. Our study demonstrates the potential of public genomic data to test for general patterns of migratory gene candidates in a cross-species comparative context, and raise questions on the applicability of candidate gene approaches in a macro-evolutionary context to understand the genetic architecture of migratory behaviour.Electronic supplementary materialThe online version of this article (doi:10.1007/s00359-017-1184-6) contains supplementary material, which is available to authorized users.

Bird Species

“…In conclusion, though candidate-gene analyses may provide important insight into the regulation of behavioral traits, this approach comes with a number of limitations and is-especially in the context of migratory behavior-clearly restricted by our lack of knowledge on the genetic architecture of this fascinating phenotype and consequently the number of candidate genes for assumed and predefined candidate traits (Liedvogel et al 2011;Delmore and Liedvogel 2016). This skepticism is further emphasized by a recent study screening whole-genome data of migratory and non-migratory bird species for the presence or lack of consistency in genetic variation across a set of 25 hypothesized candidate genes for migratory traits (Lugo Ramos et al 2017). This study fails to detect a signal for migratory phenotype using different approaches and in conclusion questions the applicability of candidate-gene approaches to understand the genetic architecture of migratory behavior (Lugo Ramos et al 2017).…”

Orientation cues and mechanisms used during avian navigation: A review

“…That way, they can carry out true navigation (Kishkinev et al, 2013;Holland, 2014;Mouritsen, 2015;Chernetsov et al, 2017). Inexperienced songbirds that migrate at night have innate instincts to their migratory heading and distance (Berthold, 1999), yet the genes supporting this have not been recognized (Ramos et al, 2017). Many skilled migratory birds have evolved substantial scale maps, likely multi-coordinate and multi-sensory, that could be assumed to compensate for the displacement in an unusual location (Gagliardo et al, 2013;Holland, 2014;Mouritsen, 2015;Chernetsov et al, 2017).…”

Investigating Diadromy in Fishes and Its Loss in an -Omics Era

“…A more plausible scenario is that adaptations such as wide osmoregulatory capacity may be inherited before a species becomes diadromous and that what makes a species to become diadromous must be a gene or genes related to signaling that would start the migration. In birds, for instance, it has been hypothesized that a gene related to behavior such as circadian behavior or photoreceptors may be responsible for migratory behavior ( Lugo Ramos et al., 2017 ).…”