TY - JOUR
T1 - A molecular phylogeny of Asian species of the genus Metagonimus (Digenea)—small intestinal flukes—based on representative Japanese populations
AU - Pornruseetairatn, Siritavee
AU - Kino, Hideto
AU - Shimazu, Takeshi
AU - Nawa, Yukifumi
AU - Scholz, Tomáš
AU - Ruangsittichai, Jiraporn
AU - Saralamba, Naowarat Tanomsing
AU - Thaenkham, Urusa
N1 - Publisher Copyright:
© 2015, Springer-Verlag Berlin Heidelberg.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Metagonimus Katsurada, 1912 is a genus of small intestinal parasites. The genus comprises eight species, primarily from far-eastern Asia, with two exceptions reported from Europe. Metagonimus yokogawai, the most widespread species, is the main agent responsible for the intestinal disease, metagonimiasis, in Japan and some other East Asian countries. On the basis of the ratio of the size of the ventral and oral suckers, Metagonimus has traditionally been morphologically divided into two groups; however, the genus has not been extensively studied using molecular data. To reveal phylogenetic relationships within Metagonimus based on molecular data, we analyzed six of the seven species present in Asia using samples collected in central Japan. Maximum likelihood and Bayesian analyses of a combined 28S ribosomal DNA (rDNA), internal transcribed spacer 2 (ITS2), and mitochondrial cox1 gene sequence dataset separated the six species into two well-supported clades. One clade comprised M. yokogawai, M. takahashii, M. miyatai, and M. hakubaensis, whereas the other consisted of M. otsurui and M. katsuradai. Genetic distances calculated from 28S rDNA and ITS2 nucleotide sequences and a comparison of the predicted amino acid sequences of cox1 gene suggested that M. otsurui and M. katsuradai may have diverged recently. None of the four main morphological characters used to delimit species of Metagonimus (i.e., sucker ratio, positions of the uterus and testes, and distribution of vitelline follicles) was consistent with the distribution of species in the molecular tree.
AB - Metagonimus Katsurada, 1912 is a genus of small intestinal parasites. The genus comprises eight species, primarily from far-eastern Asia, with two exceptions reported from Europe. Metagonimus yokogawai, the most widespread species, is the main agent responsible for the intestinal disease, metagonimiasis, in Japan and some other East Asian countries. On the basis of the ratio of the size of the ventral and oral suckers, Metagonimus has traditionally been morphologically divided into two groups; however, the genus has not been extensively studied using molecular data. To reveal phylogenetic relationships within Metagonimus based on molecular data, we analyzed six of the seven species present in Asia using samples collected in central Japan. Maximum likelihood and Bayesian analyses of a combined 28S ribosomal DNA (rDNA), internal transcribed spacer 2 (ITS2), and mitochondrial cox1 gene sequence dataset separated the six species into two well-supported clades. One clade comprised M. yokogawai, M. takahashii, M. miyatai, and M. hakubaensis, whereas the other consisted of M. otsurui and M. katsuradai. Genetic distances calculated from 28S rDNA and ITS2 nucleotide sequences and a comparison of the predicted amino acid sequences of cox1 gene suggested that M. otsurui and M. katsuradai may have diverged recently. None of the four main morphological characters used to delimit species of Metagonimus (i.e., sucker ratio, positions of the uterus and testes, and distribution of vitelline follicles) was consistent with the distribution of species in the molecular tree.
KW - 28S rDNA
KW - ITS2
KW - Incongruence
KW - Interrelations
KW - Metagonimus
KW - Morphology
KW - cox1
UR - http://www.scopus.com/inward/record.url?scp=84959129485&partnerID=8YFLogxK
U2 - 10.1007/s00436-015-4843-y
DO - 10.1007/s00436-015-4843-y
M3 - Article
C2 - 26614357
AN - SCOPUS:84959129485
SN - 0932-0113
VL - 115
SP - 1123
EP - 1130
JO - Parasitology Research
JF - Parasitology Research
IS - 3
ER -