title: Physella acuta: atypical mitochondrial gene order among panpulmonates (Gastropoda).
abstract: Mitochondrial (mt) sequences are frequently used for phylogenetic reconstruction and for identification of species of molluscs. This study expands the phylogenetic range of Hygrophila (Panpulmonata) for which such sequence data are available by characterizing the full mt genome of the invasive freshwater snailPhysella acuta(Physidae). The mt genome sequences of twoP. acutaisolates from Stubblefield Lake, New Mexico, USA, differed in length (14,490vs14,314 bp) and showed 11.49% sequence divergence, whereas ITS1 and ITS2 sequences from the nuclear genome differed by 1.75%. The mt gene order ofP. acuta(cox1,P,nad6,nad5,nad1,D,F,cox2,Y,W,nad4L,C,Q,atp6,R,E,rrnS,M,T,cox3,I,nad2,K,V,rrnL,L1,A,cytb,G,H,L2,atp8,N,nad2,S1,S2,nad4) differs considerably from the relatively conserved gene order within Panpulmonata. Phylogenetic trees show that the 13 protein-encoding mt gene sequences (equivalent codons) ofP. acutagroup according to gastropod phylogeny, yet branch lengths and dN/dS ratios forP. acutaindicate elevated amino acid substitutions relative to other gastropods. This study indicates that mt sequences ofP. acutaare phylogenetically informative despite a considerable intraspecific divergence and the atypical gene order in its mt genome.
authors.affiliation: Center for Evolutionary and Theoretical Immunology (CETI), Department of Biology MSC03 2020 , University of New Mexico , 1 University Blvd NE, Albuquerque, NM 87131 , USA.
authors.forename: Journey R
authors.initials: JR
authors.lastname: Nolan
authors.affiliation: Center for Evolutionary and Theoretical Immunology (CETI), Department of Biology MSC03 2020 , University of New Mexico , 1 University Blvd NE, Albuquerque, NM 87131 , USA.
authors.forename: Ulfar
authors.initials: U
authors.lastname: Bergthorsson
authors.affiliation: Center for Evolutionary and Theoretical Immunology (CETI), Department of Biology MSC03 2020 , University of New Mexico , 1 University Blvd NE, Albuquerque, NM 87131 , USA.
authors.forename: Coen M
authors.initials: CM
authors.lastname: Adema