The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenc...The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenced. Together with the ITS sequences of 13 selected Rhododendron species and Bejaria racemosa downloaded from GenBank, we explored the infrageneric and sectional relationships of this important North Temperate genus by employing maximum-parsimony analysis using PAUP software. C. fastigiata and B. racemosa were designated as outgroups. The ITS-based tree inferred that: (1) Rhododendron was a well-supported monophyletic group, while subg. Therorhodion was basal to the rest of the genus; (2) Ledum was a member of Rhododendron, and its close relationship with the lepidote rhododendron was confirmed; (3) the lepidote rhododendron plus Ledum formed a strongly-supported monophyletic clade which was sister to the rest of the elepidote rhododendron; (4) the elepidote rhododendron formed a weakly-supported clade within which the monophyly of subg. Hynwrianthes and subg. Tsutsusi were strongly supported, while subg. Pentanthera and subg. Azaleastrum were polyphyletic; and (5) the monophyly of sect. Choniastnini, (subg. Azaleastrum) was strongly-supported, while subg. Tsutsusi could be sister to a weakly-supported clade composed of two sampled species of sect. Azaleastrum (subg. Azaleastrum) together with R. sentibarbatum, of subg. Mumeazalea.展开更多
[Objective] The aim was to select suitable gene for Chlorella identification and to identify the oil-producing microalgae.[Method] Four candidate gene sequences,the nuclear genomic rDNA of the 18S rRNA gene,internal t...[Objective] The aim was to select suitable gene for Chlorella identification and to identify the oil-producing microalgae.[Method] Four candidate gene sequences,the nuclear genomic rDNA of the 18S rRNA gene,internal transcribed spacer（ITS）,internal transcribed spacer Ⅱ（ITS Ⅱ）and the chloroplast rbcL gene,were selected for Chlorella molecular identification.Through these four candidate genes,the genetic variability and distinguish ability between intra-species and inter-species was analyzed to choose the right genes for identification of the high oil-content Chlorella.On this basis,application of these gene segments were classified and identified for five fresh-water isolated Chlorella,which oil-content is more than 30%.[Result] ITS gene was a suitable gene because of its high variation and short fragment length,meanwhile its genetic distance intra-species（0.439 6±0.135 9）was larger than inter-species（0.045 7±0.084 3）.Its sequence length varied between different species whereas highly conserved in the same species.By the application of ITS sequences,respectively,five high oil-content stains were identified as one C.vulgaris,two strains of C.sorokiniana and two strains of algae Chlorella sp.[Conclusion] This study had provided reference for the establishment of identification gene pool of Chlorella.展开更多
The first and second internal transcribed spacer(ITS1 and ITS2)regions of the ribosomal DNA from four species,Meretrix meretrix L.,Cyclina sinensis G,Mercenaria mercenaria L.,and Protothaca jedoensis L.,belonging to t...The first and second internal transcribed spacer(ITS1 and ITS2)regions of the ribosomal DNA from four species,Meretrix meretrix L.,Cyclina sinensis G,Mercenaria mercenaria L.,and Protothaca jedoensis L.,belonging to the family Veneridae were amplified by PCR and sequenced.The size of the ITS1 PCR amplification product ranged from 663 bp to 978 bp,with GC contents ranging from 60.78%to 64.97%.The size of the ITS1 sequence ranged from 585 bp to 900 bp,which is the largest range reported thus far in bivalve species,with GC contents ranging from 61.03%to 65.62%.The size of the ITS2 PCR amplification product ranged from 513 bp to 644 bp,with GC contents ranging from 61.29%to 62.73%.The size of the ITS2 sequence ranged from 281 bp to 412 bp,with CJC contents ranging from 65.21%to 67.87%.Extensive sequence variation and obvious length polymorphisms were noted for both regions in these species,and sequence similarity of ITS2 was higher than that of ITS 1 across species.The complete sequences of 5.8S ribosomal RNA gene were obtained by assembling ITS 1 and ITS2 sequences,and the sequence length in all species was 157 bp.The phylogenetic tree of Veneridae clams was reconstructed using ITS2-containing partial sequences of both 5.8S and 28S ribosomal DNA as markers and the corresponding sequence information in Arctica islandica as the outgroup.Tree topologies indicated that P jedoensis shared a close relationship with M.mercenaria and C sinensis,a distant relationship with other species.展开更多
In this study, we investigated the molecular phylogeny of 64 clinical isolates which were identified as Sporothrix schenckii sensu lato by morphological identification. All of the strains were isolates from patients f...In this study, we investigated the molecular phylogeny of 64 clinical isolates which were identified as Sporothrix schenckii sensu lato by morphological identification. All of the strains were isolates from patients from several provinces in China. The phylogeny was inferred by DNA sequence analyses based on datasets of the ribo- somal internal transcribed spacer （ITS） and a combined ITS and partial 13-tubulin region. Reference sequences were retrieved from GenBank. Results showed that all of the isolates were clustered in a distinct clade with a type of Spo- rothrix globosa. Our analysis showed that S. globosa is the causal agent of the tested sporotrichosis in China, rather than S. schenckii that was generally believed to be the case. The existence of S. schenckii in China remains to be confirmed. This study improved our understanding of the distribution of the species in S. schenckii complex.展开更多
Eight intact LTR retrotransposons （Nbr1-Nbr8） have been previously characterized from the genome of Nosema bombycis, a eu- karyotic parasite with a compact and reduced genome. Here we describe six novel transcribed ...Eight intact LTR retrotransposons （Nbr1-Nbr8） have been previously characterized from the genome of Nosema bombycis, a eu- karyotic parasite with a compact and reduced genome. Here we describe six novel transcribed Nbr elements （Nbr9-Nbr14） identified through either cDNA library or RT-PCR. Like previously determined ones, all of them belong to the Ty3/Gypsy superfamily. Retrotransposon diversity and incomplete domains with insertions （Nbr12）, deletions （Nbrll） and in-frame stop codons in coding regions （Nbr9） were detected, suggesting that both defective and loss events of LTR retrotransposon have happened in N. bornbycis genome. Analysis of selection showed that strong purifying selection acts on all elements except Nbr11. This implies that selective pressure keeps both these Nbrs and their functions in genome. Interestingly, Nbrll is under positive selection and some positively selected codons were identified, indicating that new functionality might have evolved in the Nbrll retrotransposon. Unlike other transposable elements, Nbrll has integrated into a conserved syntenic block and probably resulted in the inversion of both flanking regions. This demonstrates that transposable element is an important factor for the reshuffling and evolution of their host genomes, and may be maintained under natural selection.展开更多
Anopheles sinensis and An. anihropophagus are two morphologically indistinguishable yet genetically and behaviorally distinct mosquito species that vary dramatically in their importance as vectors of malaria inChina. ...Anopheles sinensis and An. anihropophagus are two morphologically indistinguishable yet genetically and behaviorally distinct mosquito species that vary dramatically in their importance as vectors of malaria inChina. The sequence of the ribosomal DNA internal transcribed spacer 2 (ITS2) was determined for bothspecies to assess the species differentiation. The lengths of ITS2 was 468 hp for An. sinensis and 452 hp forAn. anthropophagus. Interspecies difference in sequence was 28. 8%. Intraspecies sequence divergence wasnegligible. A PCR method was developed for distinguishing the two species based on the species-specific variations of the ITS2 sequences. The method would amplify a diagnostic fragment in length of 425 hp for An.sinensis and 253 hp for An. anthropophagus. Field collections from 12 localities in 10 provinces of China weretested. In 440 mosquitoes identified by adult morphological characteristics as An. sinensis, 291 (66. 2 % ) wereidentified later as An. sinensis and 56 (12. 7 % ) as An. anthropophagus, the remaining 93 (22. 1 % ) were notamplified by PCR. The results showed that the morphological characteritics of adult was not reliable for fieldidentification. The PCR assay was a simple, fast and reliable method for species identification.展开更多
Objective:To distinguish the difference among the Clinacanthus nutans(Burm.f.)Lindau(C.nutans)and Clinacanthus siamensis Bremek(C.siamensis)by assessing pharmacognosy characteristics,molecular aspect and also to evalu...Objective:To distinguish the difference among the Clinacanthus nutans(Burm.f.)Lindau(C.nutans)and Clinacanthus siamensis Bremek(C.siamensis)by assessing pharmacognosy characteristics,molecular aspect and also to evaluate their anti-herpes simplex virus(HSV)type 1 and type 2 activities.Methods:Macroscopic and microscopic evaluation were performed according to WHO Geneva guideline.Stomatal number,stomatal index and palisade ratio of leaves were evaluated.Genomic DNA was extracted by modified CTAB method and ITS region was amplified using PGR and then sequenced.Dry leaves were subsequently extracted with n-hexane,dichloromethane and methanol and antiviral activity was performed using plaque reduction assay and the cytotoxicity of the extracts on Vero cells was determined by MTT assay.Results:Cross section of midrib and stem showed similar major components.Leaf measurement index of stomatal number,stomatal index and palisade ratio of C.nutans were 168.32±29.49,13.83±0.86 and 6.84±0.66,respectively,while C.siamensis were 161.60±18.04,11.93±0.81and 3.37±0.31,respectively.The PCR amplification of ITS region generated the PGR product approximately 700 bp in size.There were 34 polymorphisms within the ITS region which consisted of 11 Indels and 23 nucleotide substitutions.The IC_(50)values of C.nutans extracted with n-hexane,dichloromethane and methanol against HSV-1 were(32.05±3.63)μg/mL,(44.50±2.66)μg/mL,(64.93±7.00)μg/mL,respectively where as those of C.siamensis were(60.00±11.61)μg/mL,(55.69+4.41)μg/mL,(37.39±5.85)μg/mL,respectively.Anti HSV-2 activity of n-hexane,dichloromethane and methanol C.nutans leaves extracts were(72.62±12.60)μg/mL,(65.19±21.45)μg/mL,(65.13±2.22)μg/mL,respectively where as those of C.siamensis were(46.52±4.08)μg/mL,(49.63±2.59)μg/mL,(72.64±6.52)μg/mL,respectively.Conclusions:The combination of macroscopic,microscopic and biomolecular method are able to authenticate these closely related plants and both of them have a potency to be an anti-HSV agent.展开更多
Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 a...Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 and LAMB010601） were isolated from the two areas in 2009. The morphological characteristics and molecular phylogeny of two strains are compared on the basis of observation of a light microscope, a scanning electron microscope （SEM）, a laser scanning micro-scope （LSM） and an internal transcribed spacer （ITS） sequence data. The mean cell length of strain LAMB090611 is （14.2 ± 1.8） μm （range 11.1–18.7 μm） and mean width is （10.8 ± 1.5） μm （range 8.2– 14.7 μm）. The mean cell length of strain LAMB010601 is （15.1 ± 1.2） μm （range 12.7–17.9 μm） and the mean width is （11.4 ± 1.1） μm （range 9.1–14.7 μm）, respectively. The two strains are similar in morphological characteristics, including a straight apical groove, distinct ventral pore, sulcal extension, cingulum displacement, two or four irregular shaped chloroplasts within the cell and almost equal sized epicone and hypocone. The large and round nucleus is located at the center or at the hypocone of the cell. The sequence length of the ECS strain LAMB090611 and the German strain LAMB010601 is 640 and 646 bp, respectively. The GC content is 49%. The nucleotide similarity of the two strains is 98.1%. The sequence divergence is 0.003. Both strains are confirmed as Karlo-dinium veneficum （D. Ballantine） J. Larsen and this is the first taxonomic report from China and Germany coastal waters. The population dynamics of this toxic species in the ECS and German coastal waters needs to be investigated in the near future.展开更多
文摘The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenced. Together with the ITS sequences of 13 selected Rhododendron species and Bejaria racemosa downloaded from GenBank, we explored the infrageneric and sectional relationships of this important North Temperate genus by employing maximum-parsimony analysis using PAUP software. C. fastigiata and B. racemosa were designated as outgroups. The ITS-based tree inferred that: (1) Rhododendron was a well-supported monophyletic group, while subg. Therorhodion was basal to the rest of the genus; (2) Ledum was a member of Rhododendron, and its close relationship with the lepidote rhododendron was confirmed; (3) the lepidote rhododendron plus Ledum formed a strongly-supported monophyletic clade which was sister to the rest of the elepidote rhododendron; (4) the elepidote rhododendron formed a weakly-supported clade within which the monophyly of subg. Hynwrianthes and subg. Tsutsusi were strongly supported, while subg. Pentanthera and subg. Azaleastrum were polyphyletic; and (5) the monophyly of sect. Choniastnini, (subg. Azaleastrum) was strongly-supported, while subg. Tsutsusi could be sister to a weakly-supported clade composed of two sampled species of sect. Azaleastrum (subg. Azaleastrum) together with R. sentibarbatum, of subg. Mumeazalea.
基金Supported by Key Project of Knowledge Innovation Project of Chinese Academy of Sciences(KGCX2-YW-374-3)Scientific and Technological Project of Shandong Province(2008GG20007002)~~
文摘[Objective] The aim was to select suitable gene for Chlorella identification and to identify the oil-producing microalgae.[Method] Four candidate gene sequences,the nuclear genomic rDNA of the 18S rRNA gene,internal transcribed spacer（ITS）,internal transcribed spacer Ⅱ（ITS Ⅱ）and the chloroplast rbcL gene,were selected for Chlorella molecular identification.Through these four candidate genes,the genetic variability and distinguish ability between intra-species and inter-species was analyzed to choose the right genes for identification of the high oil-content Chlorella.On this basis,application of these gene segments were classified and identified for five fresh-water isolated Chlorella,which oil-content is more than 30%.[Result] ITS gene was a suitable gene because of its high variation and short fragment length,meanwhile its genetic distance intra-species（0.439 6±0.135 9）was larger than inter-species（0.045 7±0.084 3）.Its sequence length varied between different species whereas highly conserved in the same species.By the application of ITS sequences,respectively,five high oil-content stains were identified as one C.vulgaris,two strains of C.sorokiniana and two strains of algae Chlorella sp.[Conclusion] This study had provided reference for the establishment of identification gene pool of Chlorella.
基金supported by the 10th Five Years Key Programs for Sciences and Technology Development of China(No.2004BA526B0403)National Natural Science Foundation of China(No.Z2004024)Start—up Package Program for Attract—ing Talented People(No.KK03035)from Huaihai Institute of Technology(HHIT).
文摘The first and second internal transcribed spacer(ITS1 and ITS2)regions of the ribosomal DNA from four species,Meretrix meretrix L.,Cyclina sinensis G,Mercenaria mercenaria L.,and Protothaca jedoensis L.,belonging to the family Veneridae were amplified by PCR and sequenced.The size of the ITS1 PCR amplification product ranged from 663 bp to 978 bp,with GC contents ranging from 60.78%to 64.97%.The size of the ITS1 sequence ranged from 585 bp to 900 bp,which is the largest range reported thus far in bivalve species,with GC contents ranging from 61.03%to 65.62%.The size of the ITS2 PCR amplification product ranged from 513 bp to 644 bp,with GC contents ranging from 61.29%to 62.73%.The size of the ITS2 sequence ranged from 281 bp to 412 bp,with CJC contents ranging from 65.21%to 67.87%.Extensive sequence variation and obvious length polymorphisms were noted for both regions in these species,and sequence similarity of ITS2 was higher than that of ITS 1 across species.The complete sequences of 5.8S ribosomal RNA gene were obtained by assembling ITS 1 and ITS2 sequences,and the sequence length in all species was 157 bp.The phylogenetic tree of Veneridae clams was reconstructed using ITS2-containing partial sequences of both 5.8S and 28S ribosomal DNA as markers and the corresponding sequence information in Arctica islandica as the outgroup.Tree topologies indicated that P jedoensis shared a close relationship with M.mercenaria and C sinensis,a distant relationship with other species.
基金Project supported by the National Natural Science Foundation of China （No. 31270062） and the Chongqing Science and Technology Commission （No. cstc2011jjA10089）, China
文摘In this study, we investigated the molecular phylogeny of 64 clinical isolates which were identified as Sporothrix schenckii sensu lato by morphological identification. All of the strains were isolates from patients from several provinces in China. The phylogeny was inferred by DNA sequence analyses based on datasets of the ribo- somal internal transcribed spacer （ITS） and a combined ITS and partial 13-tubulin region. Reference sequences were retrieved from GenBank. Results showed that all of the isolates were clustered in a distinct clade with a type of Spo- rothrix globosa. Our analysis showed that S. globosa is the causal agent of the tested sporotrichosis in China, rather than S. schenckii that was generally believed to be the case. The existence of S. schenckii in China remains to be confirmed. This study improved our understanding of the distribution of the species in S. schenckii complex.
基金supported by the National Basic Research Program of China(No.2005CB121000)the project of Chongqing Science & Technology Commission(CSTC,No.2006AA5019 and 2009BB1241)+1 种基金the Programme of Introducing Talents of Discipline to Universities(No.B07045)State Development Fund at Risk of Callus Silk(No.M012005-000Y-00070)
文摘Eight intact LTR retrotransposons （Nbr1-Nbr8） have been previously characterized from the genome of Nosema bombycis, a eu- karyotic parasite with a compact and reduced genome. Here we describe six novel transcribed Nbr elements （Nbr9-Nbr14） identified through either cDNA library or RT-PCR. Like previously determined ones, all of them belong to the Ty3/Gypsy superfamily. Retrotransposon diversity and incomplete domains with insertions （Nbr12）, deletions （Nbrll） and in-frame stop codons in coding regions （Nbr9） were detected, suggesting that both defective and loss events of LTR retrotransposon have happened in N. bornbycis genome. Analysis of selection showed that strong purifying selection acts on all elements except Nbr11. This implies that selective pressure keeps both these Nbrs and their functions in genome. Interestingly, Nbrll is under positive selection and some positively selected codons were identified, indicating that new functionality might have evolved in the Nbrll retrotransposon. Unlike other transposable elements, Nbrll has integrated into a conserved syntenic block and probably resulted in the inversion of both flanking regions. This demonstrates that transposable element is an important factor for the reshuffling and evolution of their host genomes, and may be maintained under natural selection.
文摘Anopheles sinensis and An. anihropophagus are two morphologically indistinguishable yet genetically and behaviorally distinct mosquito species that vary dramatically in their importance as vectors of malaria inChina. The sequence of the ribosomal DNA internal transcribed spacer 2 (ITS2) was determined for bothspecies to assess the species differentiation. The lengths of ITS2 was 468 hp for An. sinensis and 452 hp forAn. anthropophagus. Interspecies difference in sequence was 28. 8%. Intraspecies sequence divergence wasnegligible. A PCR method was developed for distinguishing the two species based on the species-specific variations of the ITS2 sequences. The method would amplify a diagnostic fragment in length of 425 hp for An.sinensis and 253 hp for An. anthropophagus. Field collections from 12 localities in 10 provinces of China weretested. In 440 mosquitoes identified by adult morphological characteristics as An. sinensis, 291 (66. 2 % ) wereidentified later as An. sinensis and 56 (12. 7 % ) as An. anthropophagus, the remaining 93 (22. 1 % ) were notamplified by PCR. The results showed that the morphological characteritics of adult was not reliable for fieldidentification. The PCR assay was a simple, fast and reliable method for species identification.
基金Supported by Office of the Higher Education CommissionThailand+1 种基金University of Phayao and CU Graduate School Thesis GrantChulalongkorn University (Grant No.5200601)
文摘Objective:To distinguish the difference among the Clinacanthus nutans(Burm.f.)Lindau(C.nutans)and Clinacanthus siamensis Bremek(C.siamensis)by assessing pharmacognosy characteristics,molecular aspect and also to evaluate their anti-herpes simplex virus(HSV)type 1 and type 2 activities.Methods:Macroscopic and microscopic evaluation were performed according to WHO Geneva guideline.Stomatal number,stomatal index and palisade ratio of leaves were evaluated.Genomic DNA was extracted by modified CTAB method and ITS region was amplified using PGR and then sequenced.Dry leaves were subsequently extracted with n-hexane,dichloromethane and methanol and antiviral activity was performed using plaque reduction assay and the cytotoxicity of the extracts on Vero cells was determined by MTT assay.Results:Cross section of midrib and stem showed similar major components.Leaf measurement index of stomatal number,stomatal index and palisade ratio of C.nutans were 168.32±29.49,13.83±0.86 and 6.84±0.66,respectively,while C.siamensis were 161.60±18.04,11.93±0.81and 3.37±0.31,respectively.The PCR amplification of ITS region generated the PGR product approximately 700 bp in size.There were 34 polymorphisms within the ITS region which consisted of 11 Indels and 23 nucleotide substitutions.The IC_(50)values of C.nutans extracted with n-hexane,dichloromethane and methanol against HSV-1 were(32.05±3.63)μg/mL,(44.50±2.66)μg/mL,(64.93±7.00)μg/mL,respectively where as those of C.siamensis were(60.00±11.61)μg/mL,(55.69+4.41)μg/mL,(37.39±5.85)μg/mL,respectively.Anti HSV-2 activity of n-hexane,dichloromethane and methanol C.nutans leaves extracts were(72.62±12.60)μg/mL,(65.19±21.45)μg/mL,(65.13±2.22)μg/mL,respectively where as those of C.siamensis were(46.52±4.08)μg/mL,(49.63±2.59)μg/mL,(72.64±6.52)μg/mL,respectively.Conclusions:The combination of macroscopic,microscopic and biomolecular method are able to authenticate these closely related plants and both of them have a potency to be an anti-HSV agent.
基金The National High-Tech Project of China under contract No.2007AA09Z110Chinese Ecology and Oceanography of Harmful Algal Blooms Project Ⅱ under contract No.2010CB428702+3 种基金the National Science Foundation Project under contract No.41176141Foundation of State Oceanic Administration of China under contract Nos 2009123 and 20100310the Basic Research Fund of the Second Institute of Oceanography,the State Oceanic Administration of China under contract No.SZ0824Joint Project between Germany and China supported by International Bureau of Federal Ministry for Education and Research under contract No.CHN06/009
文摘Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 and LAMB010601） were isolated from the two areas in 2009. The morphological characteristics and molecular phylogeny of two strains are compared on the basis of observation of a light microscope, a scanning electron microscope （SEM）, a laser scanning micro-scope （LSM） and an internal transcribed spacer （ITS） sequence data. The mean cell length of strain LAMB090611 is （14.2 ± 1.8） μm （range 11.1–18.7 μm） and mean width is （10.8 ± 1.5） μm （range 8.2– 14.7 μm）. The mean cell length of strain LAMB010601 is （15.1 ± 1.2） μm （range 12.7–17.9 μm） and the mean width is （11.4 ± 1.1） μm （range 9.1–14.7 μm）, respectively. The two strains are similar in morphological characteristics, including a straight apical groove, distinct ventral pore, sulcal extension, cingulum displacement, two or four irregular shaped chloroplasts within the cell and almost equal sized epicone and hypocone. The large and round nucleus is located at the center or at the hypocone of the cell. The sequence length of the ECS strain LAMB090611 and the German strain LAMB010601 is 640 and 646 bp, respectively. The GC content is 49%. The nucleotide similarity of the two strains is 98.1%. The sequence divergence is 0.003. Both strains are confirmed as Karlo-dinium veneficum （D. Ballantine） J. Larsen and this is the first taxonomic report from China and Germany coastal waters. The population dynamics of this toxic species in the ECS and German coastal waters needs to be investigated in the near future.
