Symbiosis, Selection, and Novelty: Freshwater Adaptation in the Unique Sponges of Lake Baikal.

Autor:	Kenny NJ; Life Sciences Department, The Natural History Museum, London, United Kingdom., Plese B; Life Sciences Department, The Natural History Museum, London, United Kingdom.; Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia., Riesgo A; Life Sciences Department, The Natural History Museum, London, United Kingdom., Itskovich VB; Limnological Institute, Siberian Branch of the Russian Academy of Science, Irkutsk, Russia.
Jazyk:	angličtina
Zdroj:	Molecular biology and evolution [Mol Biol Evol] 2019 Nov 01; Vol. 36 (11), pp. 2462-2480.
DOI:	10.1093/molbev/msz151
Abstrakt:	Freshwater sponges (Spongillida) are a unique lineage of demosponges that secondarily colonized lakes and rivers and are now found ubiquitously in these ecosystems. They developed specific adaptations to freshwater systems, including the ability to survive extreme thermal ranges, long-lasting dessication, anoxia, and resistance to a variety of pollutants. Although spongillids have colonized all freshwater systems, the family Lubomirskiidae is endemic to Lake Baikal and plays a range of key roles in this ecosystem. Our work compares the genomic content and microbiome of individuals of three species of the Lubomirskiidae, providing hypotheses for how molecular evolution has allowed them to adapt to their unique environments. We have sequenced deep (>92% of the metazoan "Benchmarking Universal Single-Copy Orthologs" [BUSCO] set) transcriptomes from three species of Lubomirskiidae and a draft genome resource for Lubomirskia baikalensis. We note Baikal sponges contain unicellular algal and bacterial symbionts, as well as the dinoflagellate Gyrodinium. We investigated molecular evolution, gene duplication, and novelty in freshwater sponges compared with marine lineages. Sixty one orthogroups have consilient evidence of positive selection. Transporters (e.g., zinc transporter-2), transcription factors (aristaless-related homeobox), and structural proteins (e.g. actin-3), alongside other genes, are under strong evolutionary pressure in freshwater, with duplication driving novelty across the Spongillida, but especially in the Lubomirskiidae. This addition to knowledge of freshwater sponge genetics provides a range of tools for understanding the molecular biology and, in the future, the ecology (e.g., colonization and migration patterns) of these key species. (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)
Databáze:	MEDLINE
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