Transcriptome-based phylogeny of endemic Lake Baikal amphipod species flock: fast speciation accompanied by frequent episodes of positive selection

Sergey A. Naumenko, Maria D. Logacheva, Nina V. Popova, Anna V. Klepikova, Aleksey A. Penin, Georgii A. Bazykin, Anna E. Etingova, Nikolai S. Mugue, Alexey S. Kondrashov, Lev Y. Yampolsky

    Research output: Contribution to journalArticlepeer-review

    37 Citations (Scopus)

    Abstract

    Endemic species flocks inhabiting ancient lakes, oceanic islands and other long-lived isolated habitats are often interpreted as adaptive radiations. Yet molecular evidence for directional selection during species flocks radiation is scarce. Using partial transcriptomes of 64 species of Lake Baikal (Siberia, Russia) endemic amphipods and two nonendemic outgroups, we report a revised phylogeny of this species flock and analyse evidence for positive selection within the endemic lineages. We confirm two independent invasions of amphipods into Baikal and demonstrate that several morphological features of Baikal amphipods, such as body armour and reduction in appendages and sensory organs, evolved in several lineages in parallel. Radiation of Baikal amphipods has been characterized by short phylogenetic branches and frequent episodes of positive selection which tended to be more frequent in the early phase of the second invasion of amphipods into Baikal when the most intensive diversification occurred. Notably, signatures of positive selection are frequent in genes encoding mitochondrial membrane proteins with electron transfer chain and ATP synthesis functionality. In particular, subunits of both the membrane and substrate-level ATP synthases show evidence of positive selection in the plankton species Macrohectopus branickii, possibly indicating adaptation to active plankton lifestyle and to survival under conditions of low temperature and high hydrostatic pressures known to affect membranes functioning. Other functional categories represented among genes likely to be under positive selection include Ca-binding muscle-related proteins, possibly indicating adaptation to Ca-deficient low mineralization Baikal waters.

    Original languageEnglish
    Pages (from-to)536-553
    Number of pages18
    JournalMolecular Ecology
    Volume26
    Issue number2
    DOIs
    Publication statusPublished - 1 Jan 2017

    Keywords

    • adaptive radiation
    • ancient lakes
    • directional selection
    • ecological opportunity

    Fingerprint

    Dive into the research topics of 'Transcriptome-based phylogeny of endemic Lake Baikal amphipod species flock: fast speciation accompanied by frequent episodes of positive selection'. Together they form a unique fingerprint.

    Cite this