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1.
The pipefishes Syngnathus abaster and S. acus have paired testes of atypical organization. Each testis is a hollow tube consisting of a single germinal compartment of the tubular type. During the reproductive period, the germinal epithelium consists of small spermatocysts containing spermatogonia or primary spermatocytes. Cysts of older germ cells, such as secondary spermatocytes and spermatids were never observed. Developing symplastic spermatids were found in the lumen of the tubule together with mature sperm and large droplet-containing cells. Most of the spermatids were giant cells with four nuclei at the same developmental stage. Symplastic spermatids, which presumably form by nuclear division not followed by cytokinesis, are a stage of spermatogenesis in pipefishes.  相似文献   

2.
Two new glycerolipids, syngaculipids A and B ( 1 and 2 ), one first naturally occurring metabolite ( 8 ), together with five known compounds ( 3 – 7 ) were isolated from the AcOEt fraction of Syngnathus acus L. (Hai-Long). Their structures were elucidated by comprehensive spectral analyses involving UV, IR, MS, 1D and 2D NMR spectra and ECD calculations. All the isolated compounds were evaluated for their cytotoxicity against A549 and HCT-116 cell lines. Compound 8 exhibited moderate cytotoxicity with IC50 values of 34.5 and 38.9 μM on the A549 and HCT-116 cell lines, respectively.  相似文献   

3.
Despite recent taxonomic evaluations of Mephitidae and North American hog‐nosed skunks, southern South American species of Conepatus have not been thoroughly examined in a systematic context. Conepatus chinga and Conepatus humboldtii were described more than 150 years ago, based on external characters such as hair coloration and size. Although historically recognized as valid species, to date no detailed systematic analysis has been performed for either of these taxa. Herein, we evaluated the taxonomic status of C. chinga and C. humboldtii within the southern part of South America using geometric morphometrics of the skull and mandible, mitochondrial DNA analysis using the cytochrome b and cytochrome oxidase c subunit I genes, and also control region and pelage pattern variation. We failed to find morphological (skull shape and pelage coloration patterns) or molecular differences between these two species; thus, we considered that the specimens assigned to C. chinga and C. humboldtii belong to the same species. Our results indicate that environmental variation seems to be responsible for shape and size variation in Conepatus skulls from southern South America. © 2013 The Linnean Society of London  相似文献   

4.
Analyses of mitochondrial DNA and morphological variation were performed on specimens of all five currently recognised Syngnathus pipefish species from the eastern Pacific Ocean with type localities currently considered to lie within the Californian marine biogeographic province: kelp pipefish Syngnathus californiensis, bay pipefish S. leptorhynchus, barred pipefish S. auliscus, barcheek pipefish S. exilis and chocolate pipefish S. euchrous. Results consistently differentiate S. auliscus from the other species and fail to distinguish all other specimens as distinct species, as indicated by extensive morphological overlap as well as incomplete lineage sorting and considerably low genetic divergence for 16s and coI genes(<1%). This study presents a taxonomic revision of eastern Pacific Syngnathus spp. and proposes the synonymy of S. leptorhynchus, S. euchrous and S. exilis, under the senior synonym, S. californiensis. There is still a need to study populations of Syngnathus spp. from north and south of the Californian province to assess whether these too are synonyms of the two-species recognised here.  相似文献   

5.
As the Black Sea and Marmara Sea population of the Broadnosed Pipefish Syngnathus cf. argentatus show some morphological differences from the Mediterranean Sea populations, some authors regard it as an endemic species Syngnathus argentatus Pallas, 1814, while others consider it as a synonym of S. typhle Linnaeus, 1758. The aim of this study is to compare the populations of the Black Sea and Sea of Marmara with the Aegean Sea population, using a combination of morphological and molecular characters, in order to clarify their taxonomic status. Sampling was carried out at three stations in the Black Sea, two in the Sea of Marmara and three in the Aegean Sea, and a total of 24 morphometric and 6 meristic characters were examined. Metric data were analysed by Principal Component Analysis (PCA) and phylogenetic relationships between the populations were analysed using both cytochrome oxidase subunit 1 (COI) gene and cytochrome b (cyt-b) gene sequences. Although constant differences were observed in snout depths between the Black Sea/Marmara Sea and the Aegean Sea populations, other morphological features and genetic analysis did not enable these populations to be differentiated. These findings indicate that S. argentatus is a synonym of S. typhle.  相似文献   

6.
7.
In order to clarify the historical origin and phylogeographic affinities of Creole cattle matrilineages throughout the American continent, we analysed published D-loop mtDNA sequences (n = 454) from Creole, Iberian and African cattle breeds. The Western European T3 haplogroup was the most common in American Creole cattle (63.6%), followed by the African T1 (32.4%) and the Near Eastern T2 haplogroups (4%). None of the sequences were found in Bos indicus types. Within the African T1 haplogroup there were two subclades, T1a and T1*, whose geographic distribution in America was clearly disjointed. T1a is a highly divergent clade originally reported for Creole cattle from Brazil and the Lesser Antilles, but whose geographic distribution in Africa remains unknown. In contrast, lineages attributable to T1* are restricted in America to the region colonized by the Spaniards. We propose a new hypothesis for the origins of Creole cattle that summarizes all previously published historical and genetic data. While the African T1* fraction in Creole cattle may have arrived in America through the Iberian breeds, the divergent T1a lineages may have been introduced by Portuguese and other European crowns from some unknown, not-yet-sampled African location. Additional molecular studies will be required for pinpointing the specific African regional source.  相似文献   

8.
This study provides data on the genetic structuring of the pipefish Syngnathus abaster in the western Mediterranean and Adriatic Seas. A total of 109 specimens were collected in brackish‐water biotopes. The control region and three other regions of the mitochondrial genome were analysed. The most relevant result was the high genetic structuring found by Bayesian inference (BI), maximum likelihood (ML) and network analyses, which were consistent in showing three well‐separated clusters of S. abaster populations. Furthermore, BI and ML did not support the monophyly of the taxon S. abaster. These results suggest the occurrence of a species complex in the study area, whose differentiation may have occurred since the Pleistocene. The results also show a very high genetic variability at the inter‐population level, with no shared haplotypes among sites. Evolutionary forces due to the fragmented nature of the brackish‐water habitats may account for the high genetic divergence found among the groups and populations. Finally, although dispersal by rafting over long distances may occasionally occur, this study suggests linear stepping‐stone model of colonization to be most likely. The complexity of the results obtained suggests that further studies are needed to elucidate the phylogeny of S. abaster.  相似文献   

9.
Phylogeographic studies using mitochondrial DNA sequence information are frequently used as the principal source of evidence to infer species boundaries. However, a critical analysis of further evidence is essential to test whether different haplotype clades identify different species. We demonstrate a hypothesis‐testing approach, using a combination of phylogeographic methods, multivariate morphometrics and matrix association tests, to investigate species boundaries in eastern Brazilian pitvipers conventionally assigned to the species Bothrops leucurus and B. pradoi. Two basal haplotype clades with partly overlapping geographical distributions are identified, which could either represent two partly sympatric species, or multiple haplotypes within one organismal lineage. We use partial Mantel matrix association tests to verify whether generalized morphology, or any of four supposedly diagnostic characters for the two species, show any association with mtDNA variation. Negative results lead to the conclusion that the haplotype clades do not denote independently evolving organismal lineages, and do not constitute separate species under any criterion.  相似文献   

10.
Changes made to the scientific names of southern African freshwater fishes since 2001 are explained and discussed. Adjustments to the phylogeny and classification of the fauna are outlined. Recent systematic studies on cyprinines are discussed and changes to the genera Labeobarbus (expanded concept), Pseudobarbus (expanded concept), and Enteromius are supported. The introduction of the family names Alestidae and Nothobranchiidae is discussed. Adjustments made to the genera Nannocharax, Micropanchax, Tilapia, Coptodon and Mastacembelus are explained. Species name changes for Hepsetus and Zaireichthys are detailed. New species described from the region, or resurrected from synonymy, since 2001 are listed.  相似文献   

11.
Uncovering biological diversity to more accurately understand diversity patterns, and ultimately the processes driving diversification, is important not only from an evolutionary perspective but also a conservation perspective. This is particularly pertinent in Africa's rivers in which overall diversity, as well as how it arose, is poorly understood in comparison with lacustrine environments. Here we investigate population divergence in the sexually dimorphic suckermouth catfish species Chiloglanis anoterus (Crass, 1960) from the African Highveld, in which we observe striking variability in exaggerated male caudal fins across its range. As this trait is likely to be indirect evidence for sexual selection by female choice, a mechanism that has been shown to increase species diversity in different taxa, we used an integrated approach to test if current diversity in this species is underestimated. Results based on phylogenetic inference, population genetics and geometric morphometrics indicate that the recognized species C. anoterus represents five distinct lineages that may be considered confirmed candidate species. We suggest that diversification in these highland catfish has been facilitated through geographical isolation in upper river catchments, and that sexual selection through female choice has probably driven variation in male caudal fin morphology. In contrast to the relatively large range size of the currently recognized species (C. anoterus), our findings highlight highly restricted ranges of the lineages identified here, indicating that these highland habitats may harbour higher levels of endemic diversity than previously thought.  相似文献   

12.
13.
The Compositae (Asteraceae) is the largest flowering plant family if described, accepted taxa are considered. Recent revisions in the taxonomy of the family have resulted in the recognition of ten subfamilies and 35 tribes. The tribe Arctotideae is one of the smallest, with around 200 species; it contains two subtribes and several hard-to-place taxa. Previous work has shown that the subtribe Arctotidinae is well defined and is restricted to southern Africa, except for the Australian genus Cymbonotus . Molecular data from internal transcribed spacer (ITS), ndh F, and trn L-F sequences were used (24 previously published sequences; 47 new sequences) to determine the patterns of relationships within the subtribe. Twenty-three samples from the ingroup, including members of all genera and all three species of Cymbonotus , were included in the analysis, together with two outgroup taxa. Cymbonotus is monophyletic and deeply embedded in the subtribe; Haplocarpha is paraphyletic and basal in position; all other genera are monophyletic; however, Arctotis has over 60 species and only eight were sampled for this study, so additional work may prove otherwise. Arctotis is nested high in the tree and has short branch lengths; this may reflect recent radiation. By contrast, the species of the paraphyletic and basal Haplocarpha have long branches, which may indicate an older radiation and a shared ancestry with the remainder of the subtribe. The presence of Cymbonotus in Australia is most probably the result of long-distance dispersal.  Journal compilation © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 1–8. No claim to original US government works  相似文献   

14.
Li QQ  Zhang YP 《Biochemical genetics》2005,43(7-8):375-386
To study the phylogenetic relationships of the macaques, five gene fragments were sequenced from 40 individuals of eight species: Macaca mulatta, M. cyclopis, M. fascicularis, M. arctoides, M. assamensis, M. thibetana, M. silenus, and M. leonina. In addition, sequences of M. sylvanus were obtained from Genbank. A baboon was used as the outgroup. The phylogenetic trees were constructed using maximum-parsimony and Bayesian methods. Because five gene fragments were from the mitochondrial genome and were inherited as a single entity without recombination, we combined the five genes into a single analysis. The parsimony bootstrap proportions we obtained were higher than those from earlier studies based on the combined mtDNA dataset. Excluding M. arctoides, our results are generally consistent with the classification of Delson (1980). Our phylogenetic analyses agree with earlier studies suggesting that the mitochondrial lineages of M. arctoides share a close evolutionary relationship with the mitochondrial lineages of the fascicularis group of macaques (and M. fascicularis, specifically). M. mulatta (with respect to M. cyclopis), M. assamensis assamensis (with respect to M. thibetana), and M. leonina (with respect to M. silenus) are paraphyletic based on our analysis of mitochondrial genes.  相似文献   

15.
The mitochondrial genome is now widely used in the study of phylogenetics and molecular evolution due to its maternal inheritance, fast evolutionary rate, and highly conserved gene content. To explore the phylogenetic relationships of the tribe Aeromachini within the subfamily Hesperiinae at the mitochondrial genomic level, we sequenced and annotated the complete mitogenomes of 3 skippers: Ampittia virgata, Halpe nephele, and Onryza maga (new mitogenomes for 2 genera) with a total length of 15,333 bp, 15,291 bp, and 15,381 bp, respectively. The mitogenomes all contain 13 protein‐coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a noncoding A + T‐rich region and are consistent with other lepidopterans in gene order and type. In addition, we reconstructed the phylogenetic trees of Hesperiinae using maximum likelihood (ML) and Bayesian inference (BI) methods based on mitogenomic data. Results show that the tribe Aeromachini in this study robustly constitute a monophyletic group in the subfamily Hesperiinae, with the relationships Coeliadinae + (Euschemoninae + (Pyrginae + ((Eudaminae + Tagiadinae) + (Heteropterinae + ((Trapezitinae + Barcinae) + Hesperiinae))))). Moreover, our study supports the view that Apostictopterus fuliginosus and Barca bicolor should be placed out of the subfamily Hesperiinae.  相似文献   

16.
A new genus belonging to the braconid wasp subfamily Doryctinae, Kauriphanes n. gen. (type species K. khalaimi n. sp.), is described from New Zealand. This genus is placed within the doryctine subtribe Caenophanina. The extent of this subtribe is discussed and the phylogenetic relationships of three of its genera were investigated using one mitochondrial and one nuclear DNA sequence markers. Similar to previous studies, the Bayesian analyses performed significantly support a clade with the included members of Caenophanina as a sister group of a clade with the examined species of Spathiini sensu stricto. The placement of the Caenophanini within Doryctini, however, is left pendant to further exhaustive phylogenetic studies. A key to genera and subgenera belonging to Caenophanina is given.  相似文献   

17.
Leaves can be a useful source of taxonomic information in plants particularly when flowers and fruits are absent during certain periods of the year. In this study, we applied an elliptic Fourier analysis (EFA)‐based morphometric technique to assess leaf morphological divergence among four species of southern African Strychnos section Densiflorae. Using leaf specimen images from field and herbarium collections, we extracted six shape variables [i.e. principal components (PCs)] from the Fourier coefficients and used these variables to describe leaf outline among the species. Our results indicate that the symmetric component of a leaf is the main source of shape differences accounting for 90.25% of total leaf shape variation and captures the more obvious range of observed shapes. PC1 of the symmetric variables describes a wide range of visually observable leaf shape among the species. MANOVA revealed significant interspecific differences except between S. innocua and S. madagascariensis, which could not be separated by outline analysis. A cross‐validated group classification suggests that S. gerrardii, with a classification rate of 88.4%, is distinct from S. madagascariensis, contrary to some taxonomic treatments. We discuss the value of geometric morphometrics at detecting subtle morphological variations and the evolutionary implications of such variations, which may be undetectable to the human eye. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 542–553.  相似文献   

18.
The pipistrelloid bats (genera Hypsugo, Neoromicia, and Pipistrellus) of Africa have been poorly studied, partly as a result of problems associated with species identification. This paper examines the diversity of pipistrelloid bats from Mount Nimba, a biodiversity hotspot in the Upper Guinean rainforest zone. Traditional morphometrics, the structure of the baculum, and sequences of the cytochrome oxidase subunit I (COI) gene were used to identify taxa. Species richness was exceptionally high and included at least ten taxa identifiable on molecular grounds. Of these, existing names could be assigned to six taxa. A seventh taxon was described as a species new to science, Neoromicia roseveari sp. nov. , and was distinguished on molecular grounds, craniodental morphology, and baculum structure. The remaining taxa may refer to as‐yet undescribed species but we lacked sufficient material to formally describe them here. The high species richness of pipistrelloid bats on Mount Nimba may be associated with the transition zone from lowland rainforest to moist savannah. © 2013 The Linnean Society of London  相似文献   

19.
Some mitochondrial introgression is common between closely related species, but distinct species rarely show substantial introgression in their entire distribution range. In this study, however, we report a complete lack of mitochondrial divergence between two sympatric species of flat periwinkles (Littorina fabalis and Littorina obtusata) which, based on previous allozyme studies, diverged approximately 1 Ma. We re‐examined their species status using both morphology (morphometric analysis) and neutral genetic markers (microsatellites) and our results confirmed that these species are well separated. Despite this, the two species shared all common cytochrome‐b haplotypes throughout their NE Atlantic distribution and no deep split between typical L. fabalis and L. obtusata haplotypes could be found. We suggest that incomplete lineage sorting explains most of the lack of mitochondrial divergence between these species. However, coalescent‐based analyses and the sympatric sharing of unique haplotypes suggest that introgressive hybridization also has occurred.  相似文献   

20.
We constructed a phylogeny of the ground beetle subgenus Nialoe ( s. lat. ), genus Pterostichus (Coleoptera: Carabidae) based on two mitochondrial (cytochrome oxidase I and 16S ribosomal DNA) and one nuclear (28S ribosomal DNA) gene sequences. Thirty-three representative species of the group and three outgroup species were analyzed. The resultant trees (maximum parsimonious, maximum likelihood and Bayesian trees of the combined data of the three gene sequences) indicated that there are two large and three small lineages in the group, some of which were supported by a previous morphology-based phylogeny. In all the analyses, the small lineage composed of two Korean species is sister to the rest of the subgenus, but relationships of other four lineages differed among the analyses and remained unresolved. The implications of the present results are discussed in terms of taxonomy and biogeography of the group.  相似文献   

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