title: Discovery of seven novel Mammalian and avian coronaviruses in the genus deltacoronavirus supports bat coronaviruses as the gene source of alphacoronavirus and betacoronavirus and avian coronaviruses as the gene source of gammacoronavirus and deltacoronavirus.
abstract: Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus, Deltacoronavirus, in the subfamily Coronavirinae. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sparrow coronavirus HKU17, magpie robin coronavirus HKU18, night heron coronavirus HKU19, wigeon coronavirus HKU20, and common moorhen coronavirus HKU21. Complete genome sequencing and comparative genome analysis showed that the avian and mammalian deltacoronaviruses have similar genome characteristics and structures. They all have relatively small genomes (25.421 to 26.674 kb), the smallest among all coronaviruses. They all have a single papain-like protease domain in the nsp3 gene; an accessory gene, NS6 open reading frame (ORF), located between the M and N genes; and a variable number of accessory genes (up to four) downstream of the N gene. Moreover, they all have the same putative transcription regulatory sequence of ACACCA. Molecular clock analysis showed that the most recent common ancestor of all coronaviruses was estimated at approximately 8100 BC, and those of Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus were at approximately 2400 BC, 3300 BC, 2800 BC, and 3000 BC, respectively. From our studies, it appears that bats and birds, the warm blooded flying vertebrates, are ideal hosts for the coronavirus gene source, bats for Alphacoronavirus and Betacoronavirus and birds for Gammacoronavirus and Deltacoronavirus, to fuel coronavirus evolution and dissemination.
authors.affiliation: Department of Microbiology, The University of Hong Kong, Hong Kong, and Guangzhou Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Patrick C Y
authors.initials: PC
authors.lastname: Woo
authors.forename: Susanna K P
authors.initials: SK
authors.lastname: Lau
authors.forename: Carol S F
authors.initials: CS
authors.lastname: Lam
authors.forename: Candy C Y
authors.initials: CC
authors.lastname: Lau
authors.forename: Alan K L
authors.initials: AK
authors.lastname: Tsang
authors.forename: John H N
authors.initials: JH
authors.lastname: Lau
authors.forename: Ru
authors.initials: R
authors.lastname: Bai
authors.forename: Jade L L
authors.initials: JL
authors.lastname: Teng
authors.forename: Chris C C
authors.initials: CC
authors.lastname: Tsang
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Bo-Jian
authors.initials: BJ
authors.lastname: Zheng
authors.forename: Kwok-Hung
authors.initials: KH
authors.lastname: Chan
authors.forename: Kwok-Yung
authors.initials: KY
authors.lastname: Yuen
mesh_terms: D000818:Animals; D001483:Base Sequence; D001715:Bird Diseases / Q000821:virology*; D001717:Birds; D002415:Cats; D002685:Chiroptera / Q000821:virology*; D003332:Coronaviridae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D003333:Coronaviridae Infections / Q000662:veterinary* / Q000821:virology*; D017934:Coronavirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D004285:Dogs; D019143:Evolution, Molecular; D016679:Genome, Viral; D000882:Haplorhini; D006801:Humans; D008322:Mammals / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012377:Rodentia; D013552:Swine; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins