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1.
Gene sequence-based genealogies of scuticociliates are different from those produced by morphological analyses. For this reason,
11 representative scuticociliates and two ambiguously related genera were chosen to test the ability of combined phylogenetic
analyses using both gene sequences and morphological/morphogenetic characteristics. Analyses of both the SSrRNA gene sequences
and the combined datasets revealed a consistent branching pattern. While the terminal branches and the order level relationships
were generally well resolved, the family level relationships remain unresolved. However, two other trees based on ITS1-5.8S-ITS2
region sequences and morphological/morphogenetic characters showed limited information, due to a lack of informative sites
in these two datasets. Our data suggest, however, that the combined analysis of morphological/morphogenetic characters and
gene sequences did produce some changes to the phylogenetic estimates of this group. 相似文献
2.
《中国海洋湖沼学报》2021,(5)
Sea pens are a highly specialized and morphologically distinct group of octocorallians,but many taxa were poorly described and their phylogenetic relationships are still poorly known.We describe two species of sea pens collected from the tropical Western Pacific:Alloptilella splendida gen.et sp.nov.and Scytalium veneris(Thomson Henderson,1906).Alloptilella splendida gen.et sp.nov.accords with the definition of the recently resurrected genus Ptilella Gray,1870 in most characters,but differs from the latter in the arrangement of autozooids and the location of mesozooids.The new species mostly resembles Pennatula naresi K(o|")lliker(1880),but differs by the location of me sozooids and the reddish color of sclerite s surrounding siphonozooids.The generic separation is also well supported by their genetic distances and the molecular phylogenetic trees constructed by the concatenated mtMutS-COI-28 S,where Alloptilella clustered with Scytalium Herklots,1858 and formed a clade with the cluster of Ptilella and Distichoptilum.Scytalium veneris,usually considered as a junior synonym of Scytalium sarsii Herklots,1858,is resurrected by recognizing their distinctive differences.This is the first record of Scytalium veneris outside its type locality,and the phylogenetic analysis indicates that Scytalium is a monophyletic group.Both the families Pennatulidae and Virgulariidae are polyphyletic,and more morphological and molecular data are needed to clarify the phylogenetic positions of pennatulacean families and genera. 相似文献
3.
Partial Sequence Analysis of Mitochondrial COI Gene of the Chinese Shrimp, Fenneropenaeus Chinensis 总被引：1，自引：0，他引：1
GAO Tianxiang LI Jian WANG Qingyin LIU JinxianThe Key Laboratory of Mariculture Ministry of Education Ocean University of China Qingdao P.R.ChinaYellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao P.R.China 《中国海洋大学学报(英文版)》2003,2(2)
Eight hundred and thirty eight base pair fragment of mitochondrial COI gene of wild and cultured populations (CP1, CP4, CP5 and CP6) of Fenneropenaeus chinensis was amplified and sequenced. The A, T, G and C contents of the sequence were 235bp (28.0% ),.307bp (36.6%), 138bp (16.5%) and 158bp (18.9%), respectively. Furthermore, 556bp fragment of the sequence was used to discuss the phylogenetic relationship among 14 Penaeidae species using Alpheus armillatus as the outgroup. From the molecular phylogenetic tree constructed by neighbor-joining method, we obtained three large shrimp groups: Farfantepenaeus, Litopenaeus and Fenneropenaeus group. The results also indicated that there were a closer genetic relationships between F. aztecus and F. paulensis, L. schmitti and L. setiferus, F. indicus and F. merguiensis, and the genus Farfantepenaeus was closer to Litopenaeus. 相似文献
4.
The evolutionary relationships and taxonomic position of two marine planktonic bacterial strains BSw20211 and BSw10014, isolated from the Canada Basin and from the Southern Ocean, respectively, were determined using a polyphasic taxonomic approach. There was a close phylogenetic relationship between the two strains and most phenotypic properties were shared. Nonetheless, they were found to belong to different species of the genus Pseudoalteromonas on the basis of genotypic analyses. Findings were consistent with the suggestion that gyrB gene sequence comparison and DNA-DNA relatedness might better define phylogenetic relationships of bacteria at the species level. However, a cut-off value of 90% gyrB gene sequence similarity was not reliable for the differentiation of species within the genus Pseudoalteromonas. 相似文献
5.
Previous studies found intraspecific diversity in Scrippsiella trochoidea A. R. Loeblich III, a widely distributed calcareous cyst-producing dinoflagellate. In this study, three strains (ST-1, ST-D6
and ST-K) of S. trochoidea isolated from the East Asian waters were studied, together with other geographical strains, to resolve their phylogenetic
relationships. For the three East Asian isolates, two highly diverse regions of nuclear-encoded ribosomal DNA (rDNA), the
5.8S rDNA and its flanking internal transcribed spacers 1 and 2, and the 5′ portion of the large-subunit rDNA (encompassing
the “D1“ and “D2” domains) were sequenced. Homologous sequences from other geographical isolates were selected from the GenBank
database and the phylogenetic relationships were inferred from the molecular data of these strains. Strains of S. trochoidea were found to cluster into three major clades (STR1, STR2 and STR3), as reported in previous studies. Two of the three strains
ST-1 and ST-K, were grouped in clade STR2, the other strain, ST-D6, belonged to clade STR3. The intraspecific diversity of
S. trochoidea in East Asian waters makes it necessary to carry out phylogenetic investigations in combination with data of biogeography,
population dynamics, and life cycle on the ecophysiology of a region. 相似文献
6.
A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial (COI, Cyt b and control region) and nuclear (5S rDNA) DNA sequence data in multigene perspective. A variety of phylogenetic analytic methods were used to clarify the current taxonomic Classification and to assess phylogenetic relationships and the evolutionary history of this genus. The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber. We confirmed that S. japonicus and S. colias were genetically distinct. Although morphologically and ecologically similar to S. colias, the molecular data showed that S. japonicus has a greater molecular affinity with S. australasicus, which conflicts with the traditional taxonomy. This phylogenetic pattern was corroborated by the mtDNA data, but incompletely by the nuclear DNA data. Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes Supports an Atlantic origin for Scomber. The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus. The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events. In addition, our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution, from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber. 相似文献
7.
Eight hundred and thirty eight base pair fragment of mitochondrial COI gene of wild and cultured populations (CP1, CP4, CP5
and CP6) of Fenneropenaeus chinensis was amplified and sequenced. The A, T, G and C contents of the sequence were 235 bp (28.0%), 307 bp (36.6%), 138 bp (16.5%)
and 158 bp (18.9%), respectively. Furthermore, 556 bp fragment of the sequence was used to discuss the phylogenetic relationship
among 14 Penaeidae species using Alpheus armillatus as the outgroup. From the molecular phylogenetic tree constructed by neighbor-joining method, we obtained three large shrimp
groups: Farfantepenaeus, Litopenaeus and Fenneropenaeus group. The results also indicated that there were a closer genetic relationships between F. aztecus and F. paulensis, L. schmitti and L. setiferus, F. indicus and F. merguiensis, and the genus Farfantepenaeus was closer to Litopenaeus. 相似文献
8.
《中国海洋湖沼学报》2021,(3)
Polysiphonia hainanensis was previously described from Hainan, China, but DNA sequence had never been provided and its phylogenetic position in Polysiphonieae has not been clear so far. The classification of Polysiphonieae has changed recently based on the molecular analyses and detail morphological anatomy, consequently, the generic assignment of some species must be reassessed. In this study, we analyzed phylogenetic relationships of P. hainanensis and the related taxa in Polysiphonieae and Streblocladieae based on rbcL sequences, with specimens collected from the type locality and the area around. Two genetic types were detected, and formed a clade with Bryocladia thyrsigera with strong bootstrap support, in which the divergence was less than 0.81%. Furthermore, based on morphological analyses, we found characteristics of Chinese specimens, number of pericentral cells, percurrent axis, determinate branchlets, branching pattern, spermatangial axes development, and arrangement of tetrasporangia, etc., were consistent with those of Bryocladia. Combined with morphological and molecular analyses, P. hainanensis was taken a synonymous of B. thyrsigera, and gametophytes of this species were found from China for the first time. 相似文献
9.
10.
In this paper,we explore possible conflict between morphological and molecular interpretations of phylogenetic relationships within the well-known peritrichous genus Zoothamnium. On the basis of morphological evidence,for a long time this genus has been believed to be a well-defined monophyletic taxon. Nonetheless,Z oothamnium exhibits higher genetic diversity than the gross morphology of its species. Here,we used all available genetic information for the small subunit of ribosomal RNA(SSU r RNA) and internal transcribed spacer region(ITS1-5.8S-ITS2) for this genus to reconstruct phylogenies for four datasets(SSU rRNA,ITS1,ITS2,and ITS1-5.8S-ITS2) and a combined dataset(SSU rRNA+ITS1-5.8SITS2) using different phylogenetic methods and with consideration of the secondary structure of the genes. Confidence in phylogenetic tree selection was assessed with the approximately unbiased test. The molecular results showed both that Zoothamnium is more likely to be polyphyletic,and morphologically similar genera Zoothamnopsis and Myoschiston were always nested among Zoothamnium species. Accordingly,as with some other groups of ciliates,to understand more fully the correct phylogeny of Zoothamnium there remains a need for additional data from both morphological and molecular studies,covering additional Zoothamnium spp. and members of closely related genera(e.g. Zoothamnopsis,Myoschiston,and Epistylis). 相似文献
11.
Batrachospermum arcuatum Kylin is typically dioecious,although some monoecious specimens have been collected from four locations in North China.In this study,B.arcuatum populations,including monoecious and dioecious thalli,were collected from seven stream segments.The nuclear DNA internal transcribed spacer(ITS)region was sequenced for the seven populations,and a phylogenetic tree was constructed using Bayesian inference to assess intraspecifi c relationships.A haplotype network was also created.The ITS region in B.arcuatum from North China comprised 822–853 bp,with 10 haplotypes detected from the seven locations.The results of this study support the inclusion of monoecious individuals in the species B.arcuatum. 相似文献
12.
《中国海洋大学学报(英文版)》2020,(5)
The mitochondrial genome(mitogenome) was 16792 bp in length, containing 13 protein coding genes(PCGs), two rRNA genes(12 S rRNA and 16 S rRNA), 22 tRNA genes, and two main non-coding regions. Among these 37 genes, 28 genes were encoded on the heavy strand, while 9 genes were transcribed on the light strand. The non-coding regions of A. dispar included a control region, a light strand replication and another 11 intergenic spacers. The CR of A. dispar contained 8 conserved sequence blocks(CSBs), a termination-associated sequence(TAS) and a pyrimidine tract. Phylogenetic analysis based on 12 PCGs revealed that A. dispar was genetically closest to Arius arius. The families Schilbeidae, Claroteidae, Mochokidae, and Ariidae formed a closely evolved clade. Molecular information from this research introduces mitogenomice data of A. dispar and suggests the phylogenetic relationships among Siluriformes. 相似文献
13.
The 16S and 18S ribosomal ribonucleic acid genes of microbial organisms collected from the contrasting environments (temperature, salinity, silicate, phosphate and nitrate, p <0.05) of the inner and outer basins of Kongsfjorden (Spitsbergen, Arctic) were studied using polymerase chain reaction-denaturing gradient gel electrophoresis(DGGE) fingerprinting. Comparison of the microbial fingerprints and the physicochemical parameters revealed that molecular methodology exhibited a greater sensitivity. Sequences obtained from bacterial DGGE were affiliated with four main phylogenetic groups of bacteria:Proteobacteria(Alpha, Beta and Gamma), Bacteroidetes, Verrucomicrobia and Cyanobacteria. The relationships between the genotype distribution of these microbes and associated biotic/abiotic factors, revealed by canonical correspondence analysis, showed that Station 1 at 30 m (outer fjord) was grouped separately from the other sites. This difference could be a consequence of the thermocline and base of the euphotic layer at this depth where the Atlantic and Arctic-type waters overlapped. 相似文献
14.
The rbcL gene of Ulva pertusa,Enteromorpha prolifera and Monostroma grevillei was amplified,sequenced and analyzed.By comparing the rbcL sequences with seven other Ulvales species retrieved from GenBank,the sequence divergences and the phyletic evolution were analyzed and the phylogenetic tree was constructed.From the phylogenetic tree,it can be found that U.pertusa,E.prolifera and U.californica group in one branch,while E.compressa,U.rigida and U.fenestrata cluster in another clade.Obviously,unlike the Enteomorpha species,the Ulva species do not gather in one branch.Therefore Ulva and Enteomorpha might be affiliates of one genus.E.compressa and E.intestinalis gathered together,which coincided with the morphological characters.However,the thallus of U.pertusa is thick and with many holes,which is different from E.prolifera in morphology.They cluster together in the phylogenetic tree with a genetic distance of 0.005.The results indicate that Ulva and Enteromorpha are not distinguished strictly. 相似文献
15.
Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study, we analyzed species and phylogenetic diversity and community structures for woody and herbaceous plants along two elevational transects on Mt. Baekhwa, South Korea. The species richness and phylogenetic diversity of woody plants showed monotonic declining patterns with increasing elevation along all transects, whereas herbaceous plants showed different patterns, such as no relationship and a reversed unimodal pattern, between the study transects. The main drivers of these patterns were climate and habitat variables for woody and herbaceous plants, respectively. In addition, the phylogenetic community structure primarily showed phylogenetic clustering regulated by deterministic processes, especially environmental filtering, such as climate or habitat factors, along the two transects, although herbaceous plants along a transect depicted phylogenetic randomness as a result of a neutral process. Our findings suggest that deterministic and neutral processes may simultaneously control the community structures along small-scale elevational gradients such as local transects, although the deterministic process may be the predominant type. 相似文献
16.
Luidia Forbes (Paxillosida: Luidiidae) are common soft bottom sea stars with 49 described species. Because of substantial morphological diversity, the taxonomy of the genus is complex and hasn’t been resolved definitely. In order to resolve general taxonomic issues, and determine species boundaries and phylogenetic relationships within the genus Luidia, the sequences of cytochrome oxidase subunit I (COI) gene from 24 specimens of Luidia, belonging to eight taxa in Chinese waters, were studied. Three sequences of two species in genus Luidia from GenBank were used to analyze the phylogenetic relationships. The molecular phylogeny exhibited three main clades, each with strong bootstrap support: Clade A including Luidia quinaria from the Sea of Japan; Clade B including seven nominal species (L. quinaria von Martens, L. yesoensis Goto, L. changi Liu, Liao and Li, L. orientalis Fisher, L. avicularia Fisher, L. longispina Sladen and L. hardwicki Gray) from Chinese waters; and Clade C including L. maculata Müller & Troschel from Chinese waters. Our molecular phylogeny results support the morphological Quinaria-Group and Alternata-Group assigned by Döderlein. Seven nominal species we sampled do not exhibit genetic distances that are large enough to recognize them as separate species. Cryptic species may exist in’ Luidia quinaria’ from the Yellow Sea and the Sea of Japan. Meaningful morphological characters need further investigation in Luidia. 相似文献
17.
Genus Grateloupia is one of the most speciose genera in family Halymeniales. It is also one of the sources for natural materials, food and medicine. With different environments, Grateloupia change their morphological characteristics, making their morphological identification very difficult. In addition, few of the species diversity in this genus has been described before. In this study, phylogenetic analysis based on rbc L gene sequence was employed to group Grateloupia collected from three locations along Chinese coast. The microsatellites were also used to evaluate their genetic diversity. In total, the tissue parts of 6 putative species were collected from G. asiatica, G. livida, G. lanceolate, G. catenata, G. turuturu and G. filicina. In order to evaluate their genetic diversity and then conserve them better, 40 microsatellites available for Grateloupia were used to evaluate their genetic diversity, and 11 microsatellites were found to be applicable to determine the genetic diversity of G. asiatica. It was found that the genetic diversity of G. asiatica around Qingdao was very rich. We suggested that the species of genus Grateloupia should be identified based on rbc L phylogenetic analysis before the diversity evaluation with microsatellites. The microsatellites should be developed for each species of Grateloupia so that their genetic diversity can be evaluated appropriately. 相似文献
18.
【目的】了解巨砺属牡蛎的系统关系和种类区分。【方法】对我国沿海分布的7种巨砺属牡蛎(香港牡蛎、有明牡蛎、熊本牡蛎、岩牡蛎、艾氏牡蛎、太平洋牡蛎、葡萄牙牡蛎)的线粒体DNA片段(COI、12S、16S和tRNAs),以及核糖体RNA基因转录间隔子序列(ITS-1、ITS-2和ITS)进行分子系统学研究。【结果】无论种间或种内,tRNAs序列差异最大,亚种内TS1序列差异最大;tRNAs和COI序列较其它序列变异更快,种间变异与种内变异之间有明显的条形码间隙;12S、16S、ITS和ITS2的种间变异与种内变异无重叠及条形码间隙;ITS1的种间变异与种内变异出现重叠。在亚种层面,12S、ITS、ITS1和ITS2的亚种间变异与亚种内变异出现重叠;16S的亚种间变异与亚种内变异无重叠及条形码间隙;tRNAs与COI序列亚种间变异与亚种内变异之间有明显的条形码间隙,有利于区分亚种。【结论】tRNAs和COI序列可用于种及亚种的鉴定。 相似文献
19.
The nuclear-encoded small subunit ribosomal RNA gene (18S rDNA) of 16 isolates of Chondrus from 8 countries were sequenced. A total of 1796 nucleotides were obtained and aligned with the phylogenetic analysis conducted. The results suggest that the entity from Dalian, China, regarded as C. sp1 is C. pinnulatus. The C. sp2 previously depicted as C. yendoi or Mazzaella japonica may belong to genus Chondrus. So, 4 Chondrus species, i.e. C. ocellatus, C. nipponicus, C. armatus, and C. pinnulatus are distributed in China. However, the entity from Connemara, Ireland, named C. crispus, is not a Chondrus species but that of Mastocarpus stellatus, although it is morphologically similar to C. crispus. Phylogenetic analysis based on complete 18S rDNA sequence data shows that genus Chondrus includes 3 main lineages: the Northern Pacific lineage, containing C. ocellatus, C. yendoi, and C. nipponicus; C. armatus, and C. pinnulatus form the sub-North Pacific lineage; and the Northern Atlantic Ocean lineage, comprising samples of C. crispus from Canada, Portugal, Ireland, Germany and France. The phylogenetic relationships indicate that genus Chondrus might have a North Pacific ancestral origin, radiated to North Atlantic area, and then formed the species C. crispus. 相似文献
20.
Randomly amplified polymorphic DNA (RAPD) technique was applied to assess the genetic variations and phylogenetic relationships
in 4 species ofPorphyra. The samples were collected from the coast of Canada, Vietnam, Zhoushan, Fujian and Qingdao in China. Amplifications with
20 primers were carried out under predetermined optimal reaction conditions (samples were first heated at 94°C for 5 min.
and followed by 45 cycles of 1 min at 94°C, 1 min at 36°C, and 2 min at 72°C, then held at 72°C for 10 min). The amplified
products were scored as present (1) or absent (0) for each DNA sample and an index of genetic similarity (F) was calculated
by using Nei & Li’s matching coefficient method (1979). The value of (1−F) was used to quantify the genetic distances between
species and construct a phylogenetic tree. The relationship indicated by the UPGMA and NJ cluster analysis on the values of
the genetic distance is in good overall agreement with classical taxonomy. The obvious differences between natural and cultivated
population ofP. haitanensi suggest that variation or hybridization with other species occurred during the culture.
Contribution No. 100 from the Experimental Marine Biology Laboratory, IOCAS.
Contribution No. 3289 from the Institute of Oceanology, Chinese Academy of Sciences.
The research supported by the Foundation of the Chinese Academy of Sciences. 相似文献