title: Co-option of bacteriophage lysozyme genes by bivalve genomes.
abstract: Eukaryotes have occasionally acquired genetic material through horizontal gene transfer (HGT). However, little is known about the evolutionary and functional significance of such acquisitions. Lysozymes are ubiquitous enzymes that degrade bacterial cell walls. Here, we provide evidence that two subclasses of bivalves (Heterodonta and Palaeoheterodonta) acquired a lysozyme gene via HGT, building on earlier findings. Phylogenetic analyses place the bivalve lysozyme genes within the clade of bacteriophage lysozyme genes, indicating that the bivalves acquired the phage-type lysozyme genes from bacteriophages, either directly or through intermediate hosts. These bivalve lysozyme genes underwent dramatic structural changes after their co-option, including intron gain and fusion with other genes. Moreover, evidence suggests that recurrent gene duplication occurred in the bivalve lysozyme genes. Finally, we show the co-opted lysozymes exhibit a capacity for antibacterial action, potentially augmenting the immune function of related bivalves. This represents an intriguing evolutionary strategy in the eukaryote-microbe arms race, in which the genetic materials of bacteriophages are co-opted by eukaryotes, and then used by eukaryotes to combat bacteria, using a shared weapon against a common enemy.
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.
authors.forename: Qian
authors.identifier: 0000-0002-5347-5697
authors.initials: Q
authors.lastname: Ren
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.|State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an, Shandong 271018, People's Republic of China.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory Breeding Base of Marine Genetic Resource, Third Institute of Oceanography, SOA, Xiamen 361005, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Jin
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Lan
authors.affiliation: College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Ye
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.
authors.forename: Kaimin
authors.initials: K
authors.lastname: Hui
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.
authors.forename: Jingmin
authors.initials: J
authors.lastname: Tan
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Divison of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 5100 Rockhill Rd., Kansas City, MO 64110, USA wyckoffg@umkc.edu.
authors.forename: Gerald J
authors.identifier: 0000-0003-2604-2666
authors.initials: GJ
authors.lastname: Wyckoff
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China guanzhu@njnu.edu.cn.
authors.forename: Guan-Zhu
authors.initials: GZ
authors.lastname: Han
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001435:Bacteriophages / Q000201:enzymology* / Q000235:genetics; D049872:Bivalvia / Q000235:genetics* / Q000382:microbiology; D019143:Evolution, Molecular; D020440:Gene Duplication; D022761:Gene Transfer, Horizontal; D009113:Muramidase / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D010802:Phylogeny; D011487:Protein Conformation; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014764:Viral Proteins; D009113:Muramidase
keywords: bacteriophage; bivalves; lysozymes; molecular evolution