RESUMEN
A taxonomic revision of the genus Trichohoplorana Breuning, 1961 is presented. A junior synonym of Trichohoplorana, Ipochiromima Sama & Sudre, 2009, syn. nov., is proposed. A junior synonym of T.dureli Breuning, 1961, I.sikkimensis (Breuning, 1982), syn. nov., is proposed. Trichohoplorana is newly recorded from Vietnam. A new species, T.nigeralbasp. nov. is described from Vietnam. Trichohoploranaluteomaculata Gouverneur, 2016 is newly recorded from China and Vietnam. Hind wings and male terminalia of T.luteomaculata are described for the first time. Trichohoplorana is redescribed, and a key to Trichohoplorana species is presented.
RESUMEN
Hynobiidae are a clade of salamanders that diverged early within the crown radiation and that retain a considerable number of features plesiomorphic for the group. Their evolutionary history is informed by a fossil record that extends to the Middle Jurassic Bathonian time. Our understanding of the evolution within the total group of Hynobiidae has benefited considerably from recent discoveries of stem hynobiids but is constrained by inadequate anatomical knowledge of some extant forms. Pseudohynobius is a derived hynobiid clade consisting of five to seven extant species living endemic to southwestern China. Although this clade has been recognized for over 37 years, osteological details of these extant hynobiids remain elusive, which undoubtedly has contributed to taxonomic controversies over the hynobiid complex Liua-Protohynobius-Pseudohynobius. Here we provide a bone-by-bone study of the cranium in the five extant species of Pseudohynobius (Ps. flavomaculatus, Ps. guizhouensis, Ps. jinfo, Ps. kuankuoshuiensis and Ps. shuichengensis) based on x-ray computer tomography data for 18 specimens. Our results indicate that the cranium in each of these species has a combination of differences in morphology, proportions and articulation patterns in both dermal and endochondral bones. Our study establishes a range of intraspecific differences that will serve as organizing hypotheses for future studies as more extensive collections of these species become available. Morphological features in the cranium for terrestrial ecological adaptation in Hynobiidae are summarized. Based on the results, we also discuss the evolution and development of several potential synapomorphies of Hynobiidae, including features of the orbitosphenoid and articular.
Asunto(s)
Cráneo/anatomía & histología , Urodelos/anatomía & histología , Animales , China , Cráneo/diagnóstico por imagen , Urodelos/clasificación , Microtomografía por Rayos XRESUMEN
Understanding the process of speciation and the factors driving the geographical distribution patterns of species is of great interest in ecology and evolutionary biology. Herein, we investigated the phylogeographic patterns, speciation, demographic history and genetic structure of the widespread endemic Odorrana graminea sensu lato in Southern China and adjacent areas. A total of 439 specimens from 68 localities were sequenced and analyzed for both mitochondrial (12S and 16S rRNA) and nuclear markers (RAG-1 and ten microsatellite loci). Phylogenetic analyses of the concatenated mtDNA data revealed five major highly divergent lineages within the O. graminea sensu lato in Southern China, and these divergent lineages were highly concordant with five geographical regions. The nuclear data showed a discordant genetic structure compared to the mtDNA lineages (Clades A, B, and C) for O. graminea sensu stricto, with an admixed pattern in the RAG-1 data and two structure clusters in the microsatellite data. The species delimitation analyses, based on three methods, supported the species status of Odorrana zhaoi and Odorrana rotodora, and revealed the existence of putative cryptic species in the O. graminea sensu stricto. In addition, one statistically significant gene flow event was detected from Clade B to Clade C based on mtDNA and RAG-1 data, and the microsatellite data suggested gene flow within the O. graminea sensu stricto. Bayesian skyline plotting analyses and ecological niche modeling supported demographic and range expansions during the LGM for Clades A and C of the O. graminea sensu stricto. In addition, ecological niche models suggested the existence of ecological divergence among the three Clades (Clades A, B and C) of the O. graminea sensu stricto. The intense uplifting of the Qinghai-Tibetan Plateau, the Quaternary climate oscillations, and drainage changes may have driven the speciation, genetic structure and phylogeoraphic patterns of the O. graminea sensu lato.
Asunto(s)
ADN Mitocondrial/genética , Ecosistema , Especiación Genética , Ranidae/clasificación , Ranidae/genética , Animales , Anuros/clasificación , Evolución Biológica , Núcleo Celular/química , Núcleo Celular/genética , China , ADN Mitocondrial/análisis , Demografía , Ecología , Flujo Génico , Marcadores Genéticos/genética , Variación Genética , Filogenia , Filogeografía , ARN Ribosómico/genética , ARN Ribosómico 16S/genéticaRESUMEN
Global climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato, distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major clades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Peninsula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations.
RESUMEN
The confusing and unstable taxonomy of Odorrana livida (Rana livida) since its first record has made it a focal frog complex for systematics. In China, four species, Odorrana nebulosa, O. graminea, O. sinica, O. leporipes, were described to closely resemble O. livida or O. chloronota based on their morphological similarities, accompanied by much taxonomic confusion because of ambiguities in the wide distribution and morphological variations. Currently O. graminea is being used as the name of a provisional monotypic species group to include all the populations in China that closely resemble O. livida or O. chloronota. Here, we conducted a range-wide molecular phylogeographic analysis of the large green odorous frog (Odorrana graminea) complex across the majority of its range in China, based on 2780 bp DNA sequences of three mitochondrial genes (12S, 16S, ND2) in 107 samples from 20 sites. Our data recognized three distinct phylogeographic lineages of the Odorrana graminea (lato sensu) complex in China, and they together with a Thailand lineage formed a monophyletic group. Among the four lineages within O. graminea complex, the average genetic distances based on the concatenated sequences of 12S, 16S and ND2 were 7.5-8.8% and those based on 16S rRNA alone were 4.2-5.5%. Furthermore, canonical discriminant functions in morphometric analyses showed significant separations of all the paired lineage comparisons in China. The aforementioned genetic divergence and mismatched phenotypes among the lineages within the Odorrana graminea complex, in addition to their non-overlapping geographic distributions, imply extensive lineage diversification. However, precise taxonomic status of these lineages needs more studies based on adequate type information and more thorough species delimitation based on analysis of differentiation in bioacoustic and nuclear genetic characters especially regarding gene flow and admixture in geographical contact zones.
Asunto(s)
Evolución Molecular , Ranidae/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , China , Ecosistema , Femenino , Masculino , Tamaño de los Órganos , Filogenia , Ranidae/anatomía & histología , Ranidae/genética , Ranidae/crecimiento & desarrolloRESUMEN
Adults of Toxascaris leonina (Nematoda: Ascarididae) live in the gastrointestinal tract of both dogs and cats, and cause significant economic losses and potential public health problem worldwide. Although many studies have given insights into this significant pathogen, to date, the complete mitochondrial (mt) genome sequence is still not available for T. leonina. Here, we sequenced the complete mt genome of T. leonina. This AT-rich (71.53%) mt genome (14,310bp) is circular and consists of 36 genes, including 12 genes for proteins, 2 genes for rRNA and 22 genes for tRNA. All mt genes of T. leonina are transcribed in the same direction. The gene order is the same as those of Ascaris spp. (Ascarididae), Toxocara spp. (Toxocaridae), Anisakis simplex and Contracaecum rudolphii B (Anisakidae), but distinct from that of Ascaridia spp. (Ascaridiidae). Phylogenetic analyses using concatenated amino acid sequences of 12 protein-coding genes by Bayesian inference (BI) showed distinct groups with high statistical support, and our data confirm that T. leonina is a member of the Ascarididae, and that this family is more closely related to the Toxocaridae rather than the Anisakidae within the Ascaridoidea. The determination of mt genome sequences of T. leonina provides novel genetic markers for studies into the systematics, population genetics and epidemiology of this parasite.
Asunto(s)
Toxascariasis/veterinaria , Toxascaris/clasificación , Toxascaris/genética , Animales , Teorema de Bayes , Gatos , Perros , Orden Génico , Marcadores Genéticos , Genoma de los Helmintos , Genoma Mitocondrial , Intestino Delgado/parasitología , Filogenia , Análisis de Secuencia de Proteína , Toxascariasis/parasitologíaRESUMEN
Sparganosis, caused by the plerocercoid larvae of members of the genus Spirometra, can cause significant public health problem and considerable economic losses. In the present study, the complete mitochondrial DNA (mtDNA) sequence of Spirometra erinaceieuropaei from China was determined, characterized and compared with that of S. erinaceieuropaei from Japan. The gene arrangement in the mt genome sequences of S. erinaceieuropaei from China and Japan is identical. The identity of the mt genomes was 99.1% between S. erinaceieuropaei from China and Japan, and the complete mtDNA sequence of S. erinaceieuropaei from China is slightly shorter (2 bp) than that from Japan. Phylogenetic analysis of S. erinaceieuropaei with other representative cestodes using two different computational algorithms [Bayesian inference (BI) and maximum likelihood (ML)] based on concatenated amino acid sequences of 12 protein-coding genes, revealed that S. erinaceieuropaei is closely related to Diphyllobothrium spp., supporting classification based on morphological features. The present study determined the complete mtDNA sequences of S. erinaceieuropaei from China that provides novel genetic markers for studying the population genetics and molecular epidemiology of S. erinaceieuropaei in humans and animals.
Asunto(s)
ADN de Helmintos/genética , ADN Mitocondrial/genética , Genoma Mitocondrial , Spirometra/genética , Animales , Secuencia de Bases , China , ADN de Helmintos/química , ADN Mitocondrial/química , Perros/parasitología , Orden Génico , Japón , Filogenia , Análisis de Secuencia de ADN , Serpientes/parasitología , Spirometra/clasificaciónRESUMEN
We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota (Amphibia, Anura, Ranidae). Embryos were derived from artificial fertilization of frogs' eggs, and the staging of development was based on morphological and physiological characteristics. Two major periods of development were designated: i) early embryonic period, from fertilization to operculum completion stage, lasted for 324 h at water temperature (WT) 18 - 23degree; ii) larval period, from operculum completion stage to tail absorbed stage, took 1207 h at WT 20 - 24degree. Tadpoles of the concave-eared torrent frogs showed no evidence of abdominal sucker. Absence of this key characteristic supports the view from molecular systematics that concave-eared torrent frog does not belong to the genus Amolops. Two cleavage patterns were observed in embryos at 8-cell and 16-cell stages, with Pattern I - 2 (latitudinal cleavage at the 8-cell stage, and meridional cleavage at the 16-cell stage with two perpendicular meridional furrows) being the predominant pattern and only 1.5% belonging to Pattern II (meridional cleavage at the 8-cell stage and latitudinal cleavage at the 16-cell stage). The factors affecting cleavage and hatching ratios, developmental speed, and ecological adaptation were discussed.