Authors:	Schmidt, Hanno Greshake, Bastian Feldmeyer, Barbara Hankeln, Thomas Pfenninger, Markus
Title:	Genomic basis of ecological niche divergence among cryptic sister species of non-biting midges
Online publication date:	13-Oct-2022
Year of first publication:	2013
Language:	english
Abstract:	BACKGROUND There is a lack of understanding the evolutionary forces driving niche segregation of closely related organisms. In addition, pinpointing the genes driving ecological divergence is a key goal in molecular ecology. Here, larval transcriptome sequences obtained by next-generation-sequencing are used to address these issues in a morphologically cryptic sister species pair of non-biting midges (Chironomus riparius and C. piger). RESULTS More than eight thousand orthologous open reading frames were screened for interspecific divergence and intraspecific polymorphisms. Despite a small mean sequence divergence of 1.53% between the sister species, 25.1% of 18,115 observed amino acid substitutions were inferred by α statistics to be driven by positive selection. Applying McDonald-Kreitman tests to 715 alignments of gene orthologues identified eleven (1.5%) genes driven by positive selection. CONCLUSIONS Three candidate genes were identified as potentially responsible for the observed niche segregation concerning nitrite concentration, habitat temperature and water conductivity. Additionally, signs of positive selection in the hydrogen sulfide detoxification pathway were detected, providing a new plausible hypothesis for the species' ecological differentiation. Finally, a divergently selected, nuclear encoded mitochondrial ribosomal protein may contribute to reproductive isolation due to cytonuclear coevolution.
DDC:	570 Biowissenschaften 570 Life sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 10 Biologie
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-7974
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/2.0/
Journal:	BMC genomics 14
Pages or article number:	Art. 384
Publisher:	BioMed Central
Publisher place:	London
Issue date:	2013
ISSN:	1471-2164
Publisher URL:	http://dx.doi.org/10.1186/1471-2164-14-384
Publisher DOI:	10.1186/1471-2164-14-384
Appears in collections:	DFG-OA-Publizieren (2012 - 2017)