Horizontal Transfer and Gene Loss Shaped the Evolution of Alpha-Amylases in Bilaterians. Issue 2 (1st February 2020)

• Record Type: Journal Article
• Authors: Desiderato, Andrea; Barbeitos, Marcos; Gilbert, Clément; Da Lage, Jean-Luc
• Is Part Of: G3. Volume 10:Issue 2(2020)
• Page Start: 709
• Page End: 719
• Publication Date: 2020-02-01
• Subjects: alpha-amylase -- gene loss -- horizontal gene transfer -- hemichordates -- brachiopods -- phoronids -- bryozoans -- molluscs -- annelids -- Bilateria -- glycosyl hydrolase -- introns; Genetics -- Research -- Periodicals; Genomics -- Periodicals; Genetics; Genomics; Genes; Genetics -- Research; Genomics; Electronic journals; Periodical; Periodicals; Fulltext; Internet Resources; Periodicals; 572.8
• DOI: 10.1534/g3.119.400826
• Languages: English
• ISSNs: 2160-1836

Abstract

Abstract: The subfamily GH13_1 of alpha-amylases is typical of Fungi, but it is also found in some unicellular eukaryotes ( e.g., Amoebozoa, choanoflagellates) and non-bilaterian Metazoa. Since a previous study in 2007, GH13_1 amylases were considered ancestral to the Unikonts, including animals, except Bilateria, such that it was thought to have been lost in the ancestor of this clade. The only alpha-amylases known to be present in Bilateria so far belong to the GH13_15 and 24 subfamilies (commonly called bilaterian alpha-amylases) and were likely acquired by horizontal transfer from a proteobacterium. The taxonomic scope of Eukaryota genomes in databases has been greatly increased ever since 2007. We have surveyed GH13_1 sequences in recent data from ca. 1600 bilaterian species, 60 non-bilaterian animals and also in unicellular eukaryotes. As expected, we found a number of those sequences in non-bilaterians: Anthozoa (Cnidaria) and in sponges, confirming the previous observations, but none in jellyfishes and in Ctenophora. Our main and unexpected finding is that such fungal (also called Dictyo-type) amylases were also consistently retrieved in several bilaterian phyla: hemichordates (deuterostomes), brachiopods and related phyla, some molluscs and some annelids (protostomes). We discuss evolutionary hypotheses possibly explaining the scattered distribution of GH13_1 across bilaterians, namely, the retention of the ancestral gene in those phyla only and/or horizontal transfers from non-bilaterian donors.