title: No more time to stay 'single' in the detection of Anisakis pegreffii, A. simplex (s. s.) and hybridization events between them: a multi-marker nuclear genotyping approach.
abstract: A multi-marker nuclear genotyping approach was performed on larval and adult specimens of Anisakis spp. (N = 689) collected from fish and cetaceans in allopatric and sympatric areas of the two species Anisakis pegreffii and Anisakis simplex (s. s.), in order to: (1) identify specimens belonging to the parental taxa by using nuclear markers (allozymes loci) and sequence analysis of a new diagnostic nuclear DNA locus (i.e. partial sequence of the EF1 α-1 nDNA region) and (2) recognize hybrid categories. According to the Bayesian clustering algorithms, based on those markers, most of the individuals (N = 678) were identified as the parental species [i.e. A. pegreffii or A. simplex (s. s.)], whereas a smaller portion (N = 11) were recognized as F1 hybrids. Discordant results were obtained when using the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) of the internal transcribed spacer (ITS) ribosomal DNA (rDNA) on the same specimens, which indicated the occurrence of a large number of 'hybrids' both in sympatry and allopatry. These findings raise the question of possible misidentification of specimens belonging to the two parental Anisakis and their hybrid categories derived from the application of that single marker (i.e. PCR-RFLPs analysis of the ITS of rDNA). Finally, Bayesian clustering, using allozymes and EF1 α-1 nDNA markers, has demonstrated that hybridization between A. pegreffii and A. simplex (s. s.) is a contemporary phenomenon in sympatric areas, while no introgressive hybridization takes place between the two species.
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza -University of Rome',P.le Aldo Moro,5 00185 Rome,Italy.
authors.forename: S
authors.initials: S
authors.lastname: Mattiucci
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza -University of Rome',P.le Aldo Moro,5 00185 Rome,Italy.
authors.forename: V
authors.initials: V
authors.lastname: Acerra
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza -University of Rome',P.le Aldo Moro,5 00185 Rome,Italy.
authors.forename: M
authors.identifier: 0000-0002-0950-0576
authors.initials: M
authors.lastname: Paoletti
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza -University of Rome',P.le Aldo Moro,5 00185 Rome,Italy.
authors.forename: P
authors.initials: P
authors.lastname: Cipriani
authors.affiliation: National Institute of Nutrition and Seafood Research (NIFES),Strandgaten 229,N-5004 Bergen,Norway.
authors.forename: A
authors.initials: A
authors.lastname: Levsen
authors.affiliation: Cawthron Institute,Private Bag 2,Nelson 7042,New Zealand.
authors.forename: S C
authors.initials: SC
authors.lastname: Webb
authors.affiliation: Department of Ecological and Biological Sciences,Tuscia University,Viale dell'Università s/n 01100 Viterbo,Italy.
authors.forename: D
authors.identifier: 0000-0001-9351-4972
authors.initials: D
authors.lastname: Canestrelli
authors.affiliation: Department of Ecological and Biological Sciences,Tuscia University,Viale dell'Università s/n 01100 Viterbo,Italy.
authors.forename: G
authors.initials: G
authors.lastname: Nascetti
mesh_terms: D000818:Animals; D017129:Anisakiasis / Q000469:parasitology / Q000662:veterinary*; D017163:Anisakis / Q000235:genetics* / Q000302:isolation & purification; D002467:Cell Nucleus / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005260:Female; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D005843:Geography; D006824:Hybridization, Genetic; D007814:Larva; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D013045:Species Specificity
chemical_list: D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers
keywords: A. simplex (s. s.); Anisakis pegreffii; contemporary hybridization; elongation factor 1 alpha1 nDNA (EF1 α-1 nDNA region); multi-marker genotyping approach