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1.
The mole vole subgenus Ellobius is currently considered to include three species: Ellobius talpinus (distributed from SE Europe and Turkmenistan through Kazakhstan to SW Siberia), Ellobius alaicus (S Tianshan, Pamir-Alay) and Ellobius tancrei (East and West Central Asia, from the Amu-Darya to Mongolia and N China). A study focusing on the genetic variation in Ellobius from Mongolia was conducted using one mitochondrial and three nuclear markers. Two divergent allopatric lineages endemic to East Central Asia were revealed. The first lineage occurs from Dzungaria eastwards to central Mongolia and represents E. tancrei sensu stricto. The second lineage is found in East Gobi only and corresponds to a taxon described as Ellobius orientalis, which has been traditionally treated as a subspecies of E. tancrei. However, molecular and chromosome data indicate that orientalis is related not to E. tancrei but to E. talpinus, which is separated from the former by a distribution gap of ~2,000 km. The taxonomic status of the East Gobi mole vole is ambiguous, and its genetic distance from E. talpinus s. str. falls into the range characteristic for closely related vole species or semi-species. According to molecular estimates, the two taxa have been isolated since the late Middle Pleistocene. A similar divergence is observed between the East and West Central Asian lineages of E. tancrei. E. alaicus is placed as sister to the latter rendering E. tancrei sensu lato paraphyletic. The revealed phylogeographic pattern implies that East Central Asia was colonized by mole voles through multiple eastward dispersal events.  相似文献   

2.
The taxonomic status of Rhinolophus macrotis sensu lato (s.l.) in Vietnam and adjacent territories remains problematic. To address this issue, we performed an integrated study of morphological, acoustic, and genetic characters of R. macrotis s.l. specimens and compared these with sympatric species within the philippinensis group (R. marshalli, R. paradoxolophus, and R. rex). Our results reveal that in addition to a cryptic species of R. macrotis previously found in Jiangxi and Jingmen, China, R. macrotis s.l. in continental Asia includes three further species, namely R. cf. siamensis, R. cf. macrotis, and R. cf. macrotis “Phia Oac.” These four taxa are distinguished from genuine R. macrotis in Nepal and R. siamensis in Thailand by their morphological and/or genetic features. Further taxonomic evaluation of the subspecies of R. macrotis s.l. is needed to determine their affinities with recently recognized cryptic species and to possibly describe new taxa. Our results also show that interspecific divergences in mitochondrial DNA sequences (Cytb and COI genes) among taxa within the philippinensis group (particularly between R. cf. siamensis/R. cf. macrotis and R. rex/R. paradoxolophus) are significantly lower than those of other morphological groups in the genus. These phylogenetic patterns might be explained by recent allopatric speciation or ancient introgression events among ancestors of the taxa during the Pleistocene. However, further investigations including genetic analyses of nuclear genes are needed to test the latter hypothesis.  相似文献   

3.
4.
Seventy-five taxa belonging to the genus Asarum sensu lato were studied for their composition of flavonoids. Three chalcones and an aurone were found as major components. The chalcones were identified as chalcononaringenin 2′,4′-di-O-glucoside, 4,2′,4′-tri-O-glucoside, 4-O-glucoside, and the aurone as aureisidin 4,6-di-O-glucoside. The glycoside, 2′,4′-di-O-glucoside was detected in all taxa examined, and is a chemotaxonomical feature of Asarum sensu lato. 4,2′,4′-Tri-O-glucoside was found from the taxa classified into the genera Asiasarum, Geotaenium and Heterotropa by Maekawa's system. On the other hand, the glycoside was not detected from three Asarum sensu stricto species, A. caudigerum, A. caulescens and A. leptophyllum. In contrast, aurone, aureusidin 4,6-di-O-glucoside occurred in two Asarum s.s., A. caulescens and A. leptophyllum. Thus, the Asarum s.s. and other Maekawa's genera, Asiasarum, Geotaenium and Heterotropa could distinguish by the presence or absence of some anthochlor pigments. Other flavonoids were isolated from the selected 18 Asarum species. They were characterized as some flavonol 3- or 3,7-O-glycosides based on kaempferol, quercetin and isorhamnetin, flavone, apigenin 6,8-di-C-glycoside, flavanone, naringenin 5,7-di-O-glucoside, and xanthone, mangiferin.  相似文献   

5.
Freshwater mollusk shell morphology exhibits clinal variation along a stream continuum that has been termed the Law of Stream Distribution. We analyzed phylogenetic relationships and morphological similarity of two freshwater mussels (Bivalvia: Unionidae), Obovaria jacksoniana and Villosa arkansasensis, throughout their ranges. The objectives were to investigate phylogenetic structure and evolutionary divergence of O. jacksoniana and V. arkansasensis and morphological similarity between the two species. Our analyses were the first explicit tests of phenotypic plasticity in shell morphologies using a combination of genetics and morphometrics. We conducted phylogenetic analyses of mitochondrial DNA (1416 bp; two genes) and morphometric analyses for 135 individuals of O. jacksoniana and V. arkansasensis from 12 streams. We examined correlations among genetic, morphological, and spatial distances using Mantel tests. Molecular phylogenetic analyses revealed a monophyletic relationship between O. jacksoniana and V. arkansasensis. Within this O. jacksoniana/V. arkansasensis complex, five distinct clades corresponding to drainage patterns showed high genetic divergence. Morphometric analysis revealed relative differences in shell morphologies between the two currently recognized species. We conclude that morphological differences between the two species are caused by ecophenotypic plasticity. A series of Mantel tests showed regional and local genetic isolation by distance. We observed clear positive correlations between morphological and geographic distances within a single drainage. We did not observe correlations between genetic and morphological distances. Phylogenetic analyses suggest O. jacksoniana and V. arkansasensis are synonomous and most closely related to a clade composed of Oretusa, Osubrotunda, and Ounicolor. Therefore, the synonomous O. jacksoniana and V. arkansasensis should be recognized as Obovaria arkansasensis (Lea 1862) n. comb. Phylogenetic analyses also showed relative genetic isolation among drainages, suggesting no current gene flow. Further investigation of in‐progress speciation and/or cryptic species within O. arkansasensis is warranted followed by appropriate revision of conservation management designations.  相似文献   

6.
Evolutionary relationships in the widely distributed velvet worm Peripatopsis balfouri sensu lato species complex were examined using DNA sequence data, gross and SEM morphology. Sequence data were generated for the COI mtDNA and the 18S rRNA loci and analysed using a Bayesian inference approach, maximum likelihood and maximum parsimony. Phylogenetic analyses of the combined DNA sequence data revealed that Peripatopsis clavigera specimens from the southern Cape (clade 1) was sister to P. balfouri sensu lato specimens from the Cederberg Mountains (clade 2). Within the main P. balfouri sensu lato species complex, three addition clades could be discerned (clades 3, 4 and 5). The obligatory troglobitic species Peripatopsis alba was equidistant between the Cape Peninsula and adjacent interior (clade 3) and the two Boland and Hottentots Holland Mountains (clades 4 and 5). On the Cape Peninsula, P. stelliporata specimens nested among the sympatric P. balfouri sensu lato specimens. The Cape Peninsula specimens were sister to specimens from Jonkershoek site 1, Kogelberg and Simonsberg. Two Boland clades were retrieved, comprising Du Toit's Kloof, Bain's Kloof and Mitchell's Pass and sister (in clade 4) to specimens from the Boland and adjacent Hottentots Holland Mountains in clade 5. These results revealed complex biogeographic patterning in the P. balfouri sensu lato species complex. The presence of sympatric, yet genetically discrete species pairs at six of the sample localities (Du Toit's Kloof, Simonsberg, Jonkershoek sites 1 and 2, Kogelberg and Landroskop) suggests that there is reproductive isolation between the lineages. Divergence time estimations suggest a Miocene/Pliocene/Pleistocene cladogenesis. A taxonomic revision of the P. balfouri sensu lato species complex was undertaken to stabilize the taxonomy. P. clavigera is monophyletic and retained for the southern Cape specimens, P. balfouri sensu stricto is now confined to the Cape Peninsula and adjacent interior, while P. stelliporata is regarded as a junior synonym of the latter taxon, P. alba is endemic to the Wynberg Cave systems on the Cape Peninsula. Three novel species (Peripatopsis cederbergiensis, sp. n., Peripatopsis bolandi sp. n. and Peripatopsis purpureus, sp. n.) are described.  相似文献   

7.
Flavonoids in 19 Cyrtomium, three Cyrtogonellum and two Phanerophlebia taxa were surveyed. Major flavonoids were flavonol O-glycosides based on kaempferol, quercetin, and sometimes myricetin, and C-glycosylflavones, such as isovitexin, vitexin, isoorientin, orientin and their O-glycosides. The C-methylflavanones, farrerol and cyrtominetin, and their 7-O-glucosides were isolated from Cyrtomium devexiscapulae and Cyrtomium laetevirens. Flavanones have been reported from Cyrtomium falcatum sensu lato. Though C. falcatum sensu lato is divided into four taxa, i.e. C. falcatum subsp. falcatum, C. falcatum subsp. australe, C. falcatum subsp. littorale, and C. devexiscapulae, the occurrence of the flavanones was restricted to C. devexiscapulae, and they did not occur in C. falcatum sensu stricto.  相似文献   

8.
Cladistic analyses were carried out to infer the phylogenetic relationships among taxa that were originally part of the large genus Eumenes. Terminals belonging to other eumenine lineages were also included, as well as terminals from other vespid subfamilies. Analyses under equal weights and implied weights were carried out, and better results were obtained with the latter. The results corroborated the monophyly of Eumeninae, and recovered Zethini sensu lato as the sister‐lineage to the remaining eumenines. Eumenes sensu lato as originally recognized is paraphyletic relative to Odynerus sensu lato. A natural classification at the tribal level congruent with the phylogenetic results may be proposed, and the names Zethini, Odynerini, and Eumenini are already available. This is the most comprehensive phylogeny of the Eumeninae to date. A new generic synonymy is Alfieria Giordani Soika, 1934 = Delta de Saussure, 1855.  相似文献   

9.
Sponges are among the most species‐rich and ecologically important taxa on coral reefs, yet documenting their diversity is difficult due to the simplicity and plasticity of their morphological characters. Genetic attempts to identify species are hampered by the slow rate of mitochondrial sequence evolution characteristic of sponges and some other basal metazoans. Here we determine species boundaries of the Caribbean coral reef sponge genus Callyspongia using a multilocus, model‐based approach. Based on sequence data from one mitochondrial (COI), one ribosomal (28S), and two single‐copy nuclear protein‐coding genes, we found evolutionarily distinct lineages were not concordant with current species designations in Callyspongia. While C. fallax, C. tenerrima, and C. plicifera were reciprocally monophyletic, four taxa with different morphologies (C. armigera, C. longissima, C. eschrichtii, and C. vaginalis) formed a monophyletic group and genetic distances among these taxa overlapped distances within them. A model‐based method of species delimitation supported collapsing these four into a single evolutionary lineage. Variation in spicule size among these four taxa was partitioned geographically, not by current species designations, indicating that in Callyspongia, these key taxonomic characters are poor indicators of genetic differentiation. Taken together, our results suggest a complex relationship between morphology and species boundaries in sponges.  相似文献   

10.
Over the past several years, there has been growing interest in how bones of decaying mammals are colonized in the marine seabed. One of the most common opportunistic taxa occurring worldwide on bones is dorvilleid polychaetes of the genus Ophryotrocha. In a recent study in the Mediterranean, Ophryotrocha puerilis and Ophryotrocha alborana were two of the most abundant species occurring in experimentally deployed bones. These species have direct development and this makes them a suitable model to study the mechanisms and processes allowing organisms lacking a dispersive larval phase to colonize new substrates. Here, we address the colonization processes at the molecular level for populations of O. puerilis and O. alborana on experimentally deployed mammal bones in the shallow‐water Mediterranean collected over a year at 3‐month intervals. High genetic distances between some of the O. puerilis organisms collected indicated the occurrence of at least two cryptic sibling species (O. puerilis ‘Shallow’ and O. puerilis ‘Deep’) apart from O. puerilis sensu stricto. This was corroborated with phylogenetic analyses using an alignment of three concatenated genes (COI, 16S, H3) and with species delimitation analyses using COI. The haplotype network inferred from COI sequences for O. puerilis ‘Shallow’ showed a few common haplotypes shared between the two trimesters analysed and several other less represented haplotypes only present in one trimester. Thus, colonization of these experimental bones may have been achieved by a few organisms that arrived to the bones and were able to reseed, and by several individuals arriving to the experimental bones and not persisting across time. In contrast, the haplotype network for O. alborana revealed that none of the haplotypes present in three different trimesters were shared, suggesting that the populations arriving at the bones during each trimester were totally replaced by new individuals during the subsequent trimesters. Our study suggests that different species of shallow‐water Ophryotrocha occurring in the Mediterranean may have different patterns of substrate colonization despite sharing similar life histories.  相似文献   

11.
The European genus Ophrys (Orchidaceae) is famous for its insect‐like floral morphology, an adaptation for a pseudocopulatory pollination strategy involving Hymenoptera males. A large number of endemic Ophrys species have recently been described, especially within the Mediterranean Basin, which is one of the major species diversity hotspots. Subtle morphological variation and specific pollinator dependence are the two main perceptible criteria for describing numerous endemic taxa. However, the degree to which endemics differ genetically remains a challenging question. Additionally, knowledge regarding the factors underlying the emergence of such endemic entities is limited. To achieve new insights regarding speciation processes in Ophrys, we have investigated species boundaries in the Fly Orchid group (Ophrys insectifera sensu lato) by examining morphological, ecological and genetic evidence. Classically, authors have recognized one widespread taxon (O. insectifera) and two endemics (O. aymoninii from France and O. subinsectifera from Spain). Our research has identified clear morphological and ecological factors segregating among these taxa; however, genetic differences were more ambiguous. Insights from cpDNA sequencing and amplified fragment length polymorphisms genotyping indicated a recent diversification in the three extant Fly Orchid species, which may have been further obscured by active migration and admixture across the European continent. Our genetic results still indicate weak but noticeable phylogeographic clustering that partially correlates with the described species. Particularly, we report several isolated haplotypes and genetic clusters in central and southeastern Europe. With regard to the morphological, ecological and genetic aspects, we discuss the endemism status within the Fly Orchid group from evolutionary, taxonomical and conservation perspectives.  相似文献   

12.
Phylogenetic relationships, taxonomy and nomenclature issues within East Asian voles Alexandromys were addressed using comprehensive species samples, including all 12 valid species of the genus, and multilocus analysis. We examined the mitochondrial cytochrome b (cytb) gene and three nuclear genes in 36 specimens. Additionally, we examined a data set of 106 specimens using only the cytb gene. Our results did not confirm the aggregation of A. kikuchii, A. montebelli and A. oeconomus into a separate clade, namely the subgenus Pallasiinus. Analysis of incomplete lineage sorting using JML software highlighted both the cases of mitochondrial introgression and incomplete lineage sorting within the genus. Thus, the sister position of A. sachalinensis and A. maximowiczii in mitochondrial trees could be explained by mitochondrial introgression, while the sister position of A. limnophilus and A. fortis in mitochondrial trees could be successfully explained by incomplete lineage sorting. Very short genetic distances, together with an absence of monophyly, of the three species, A. evoronensis, A. mujanensis and A. maximowiczii, is supported by multiple morphological data, which indicates that these three taxa should be one species—A. maximowiczii. Analysis of genetic distances and tree topology revealed that three species of short‐tailed voles—A. middendorffii, A. mongolicus and A. gromovi—are more closely related to each other than to other established species of Alexandromys. The lacustrine vole, A. limnophilus, is closely related to the group of short‐tailed voles. Analysis of the type specimens of limnophilus and flaviventris confirmed that these taxa form one species together with A. l. malygini. Our results suggest that the mountains of western Mongolia are inhabited by a new taxon of short‐tailed voles of the same rank as middendorffii, mongolicus and gromoviA. malpinus ssp. n.  相似文献   

13.
The classical athecate dinoflagellate genera (Amphidinium, Gymnodinium, Gyrodinium) have long been recognized to be polyphyletic. Amphidinium sensu lato is the most diverse of all marine benthic dinoflagellate genera; however, following the redefinition of this genus ~100 species remain now of uncertain or unknown generic affiliation. In an effort to improve our taxonomic and phylogenetic understanding of one of these species, namely Amphidinium semilunatum, we re‐investigated organisms from several distant sites around the world using light and scanning electron microscopy and molecular phylogenetic methods. Our results enabled us to describe this species within a new heterotrophic genus, Ankistrodinium. Cells of A. semilunatum were strongly laterally flattened, rounded‐quadrangular to oval in lateral view, and possessed a small asymmetrical epicone. The sulcus was wide and characteristically deeply incised on the hypocone running around the antapex and reaching the dorsal side. The straight acrobase with hook‐shaped end started at the sulcal extension and continued onto the epicone. The molecular phylogenetic results clearly showed that A. semilunatum is a distinct taxon and is only distantly related to species within the genus Amphidinium sensu stricto. The nearest sister group to Ankistrodinium could not be reliably determined.  相似文献   

14.
DNA barcodes have great potential to assist in species identification, especially when high taxonomical expertise is required. We investigated the utility of the 5′ mitochondrial cytochrome c oxidase I (COI) region to discriminate between 13 European cicada species. These included all nine species currently recognized under the genus Tettigettalna, from which seven are endemic to the southern Iberian Peninsula. These cicadas have species‐specific male calling songs but are morphologically very similar. Mean COI divergence between congeners ranged from 0.4% to 10.6%, but this gene was proven insufficient to determine species limits within genus Tettigettalna because a barcoding gap was absent for several of its species, that is, the highest intraspecific distance exceeded the lowest interspecific distance. The genetic data conflicted with current taxonomic classification for T. argentata and T. mariae. Neighbour‐joining and Bayesian analyses revealed that T. argentata is geographically structured (clades North and South) and might constitute a species complex together with T. aneabi and T. mariae. The latter diverges very little from the southern clade of T. argentata and shares with it its most common haplotype. T. mariae is often in sympatry with T. argentata but it remains unclear whether introgression or incomplete lineage sorting may be responsible for the sharing of haplotypes. T. helianthemi and T. defauti also show high intraspecific variation that might signal hidden cryptic diversity. These taxonomic conflicts must be re‐evaluated with further studies using additional genes and extensive morphological and acoustic analyses.  相似文献   

15.
We present a phylogenetic investigation of the Northern Clade, the major monophyletic clade within the freshwater fish family Cobitidae, one of the most prominent families of freshwater fishes found in Asian and European waters. Phylogenetic reconstructions based on the cytochrome b and RAG-1 genes show the genera Microcobitis, Sabanejewia, Koreocobitis and Kichulchoia as monophyletic groups. These reconstructions also show a Cobitis sensu lato and a Misgurnus sensu lato group. The Cobitis sensu lato group includes all species of Cobitis, Iksookimia, Niwaella and Kichulchoia, while the Misgurnus sensu lato group includes Misgurnus, Paramisgurnus and Koreocobitis. Although the monophyly of both the Cobitis sensu lato and Misgurnus sensu lato groups is supported, relationships within the groups are incongruent with current generic definitions. The absence of monophyly of most genera included in the Cobitis sensu lato group (Cobitis, Iksookimia and Niwaella) or their low genetic differentiation (Kichuchoia) supports their consideration as synonyms of Cobitis. Molecular phylogenies indicate that the Asian species of Misgurnus experienced a mitochondrial introgression from a lineage of Cobitis. We also find two nuclear haplotypes in the same Cobitis species from the Adriatic area that, in the absence of morphological differentiation, may indicate molecular introgression. Most lineages within the Northern Clade consist of species found in East Asia. However, some lineages also contain species from Europe and Asia Minor. The phylogenetic relationships presented here are consistent with previous studies suggesting an East Asian origin of the Northern Clade. According to the current distributions and phylogenetic relationships of the Misgurnus sensu lato and Cobitis clade lineages, particularly of M. fossilis and C. melanoleuca, the range expansion of East Asian species into Europe was most likely via Siberia into Northern and Central Europe. Phylogenetic analyses also show that the Cobitis sensu lato group consists of two clear subgroups (I and II), each presenting geographical differences. Subgroup I is distributed exclusively in East Asian drainages with an Eastern European offshoot (C. melanoleuca), whereas Subgroup II includes species widespread throughout Europe (including the Mediterranean), Asia Minor, the Black Sea and the Caucasus, with some lineages related to species restricted to East Asia.  相似文献   

16.
Genetic variation at eleven allozyme loci was scored in approximately 1600 individual Daphnia. The samples included representatives of all nine taxa described from the D. carinata complex in Australia. Principal coordinates and cluster analyses revealed only three groups of genotypes within the complex, corresponding to the taxa D. cephalata, D. nivalis, and a conglomerate of all other taxa described from the complex, D. carinata (sensu lato). These results are consistent with recent multivariate morphological analyses of the complex.  相似文献   

17.
We determined ∼215 bp of DNA sequence from the 3′-untranslated region (UTR) of 240 cloned L1 (LINE-1) elements isolated from 22 species of Rattus sensu lato and Rattus sensu stricto murine rodents. The sequences were sorted into different L1 subfamilies, and oligonucleotides cognate to them were hybridized to genomic DNA of various taxa. From the distribution of the L1 subfamilies in the various species, we inferred the partial phylogeny of Rattus sensu lato. The four Maxomys species comprise a well-defined clade separate from a monophyletic cluster that contains the two Leopoldamys and four Niviventer species. The Niviventer/Leopoldamys clade, in turn, shares a node with the clade that contains Berylmys, Sundamys, Bandicota, and Rattus sensu stricto. The evolutionary relationships that we deduced agree with and significantly extend the phylogeny of Rattus sensu lato established by other molecular criteria. Furthermore, the L1 amplification events scored here produced a unique phylogenetic tree, that is, in no case did a character (a given L1 amplification event) appear on more than one branch. The lack of homoplasy found in this study supports the robustness of L1 amplification events as phylogenetic markers for the study of mammalian evolution. Received: 8 November 1996 / Accepted: 11 April 1997  相似文献   

18.
Cryptic species are common in the ocean, particularly among marine invertebrates such as octopuses. Delineating cryptic species is particularly problematic in octopus taxonomy where the plasticity recorded among taxonomic characters often results in low resolution at the species level. This study investigated the morphological relationships among seven phylogenetic clades (identified using cytochrome c oxidase subunit I) of the broadly distributed Octopus vulgaris species complex and close relatives. Morphological analyses in this study were successful in delimiting O. sinensis, Brazilian Ovulgaris and O. vulgaris sensu stricto, which was congruent with the molecular findings of this study. Analyses based on male morphology were successful in distinguishing 14 of 15 total pairwise comparisons and proved to be a more reliable indicator of species‐level relationships in comparison with female morphology. The majority of characters with the greatest discriminatory power were male sexual traits. Significant morphological differences were also recorded among sampling localities of conspecifics, with phenotype showing correlation with local environmental data. The findings of this study support the hypothesis that multiple O. vulgaris‐like species are currently being incorrectly treated under a single species name, O. vulgaris. Octopuses being exported globally under the name O. vulgaris are of extremely high fisheries market value and profile. Our findings have potentially significant implications for the naming and conservation of commercially harvested members of this species complex throughout their ranges.  相似文献   

19.
 Nuclear ribosomal (ITS) DNA sequence data from representatives of eleven out of 12 genera previously included in Thlaspi sensu lato were analyzed to elucidate relationships within the former genus Thlaspi sensu lato. Sequences from Thlaspi segregates Noccaea, Masmenia, Callothlaspi, Kotschyella, Microthlaspi, and Noccidium were added to the existing data sets, and only some Thlaspi sensu lato segregates formed a monophyletic group. The recently renamed genus Pseudosempervivum, formerly part of the genus Cochlearia, has been shown to be closely related to this group as well. Microthlaspi consists of three independent lineages of which Microthlaspi umbellatum is closely related to Neurotropis. The Thlaspi s.str. taxa including the type species T. arvense, are closely related to Peltaria and Alliaria and they represent a monophyletic group. Kotschyella and Noccidium, which were also integrated into Thlaspi s.l. are not closely related to any Thlaspi lineage. Therefore, we suggest major taxonomical changes which are not in agreement with concepts based on morphological data. Our ITS based phylogeny demonstrates that subtribe Thlaspidinae comprises some additional genera such as Teesdalia, Peltaria, and Alliaria, the latter two even previously classified in other tribes than tribe Lepidieae. Received August 15, 2000 Accepted January 30, 2001  相似文献   

20.
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