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1.
Three artificial gynogenetic clones of silver carp were produced for the analysis of restriction enzyme digestion patterns
of ND5-ND6 region from mtDNA of the clones. It is revealed that all intraclonal individuals shared completely the same digestion
patterns but among interclonal individuals did not. The three clones were mixed and cultured in a pond together for two years,
and restriction endonuclease digestion patterns of ND5–ND6 were used as genetic markers to assess the growth performance of
each clone.
Project supported by the National Natural Science Foundation of China (No. 39830300). 相似文献
2.
Nematode Diversity of Qingdao Coast Inferred from the 18S Ribosomal RNA Gene Sequence Analysis 总被引：1，自引：0，他引：1
SHEN Xiquan YANG Guanpin LIU Yongjian 《中国海洋大学学报(英文版)》2007,6(2):132-136
The 18S ribosomal DNA gene （18S rDNA） sequences （approxtmately 1300 bp in length） were amplified from the DNA extracted from the free-living marine nematodes collected from the inter-tidal sediment of Qingdao coast in bulk with nematode specific primers. The PCR products were cloned, re-amplified, digested with Rsa I and Hin61 restriction endonucleases and separated in agarose gel. Among 17 restriction fragment length types, types 1, 2 and 6 covered 61.2%, 14.4% and 9.3% of the clones analyzed, respectively, while the remaining 14 only covered 21 clones, which accounted for 15.1% of the total. Twenty-four representative clones were sequenced and phylogenetically analyzed by referring to those currently available in RDP and GenBank databases. Although it was hard to assign these sequences to known species or genera due to the lack of the 18S rDNA sequence data of known marine free-living nematodes, the obtained sequences were assigned to the nematodes of Adenophorea. Among them, twelve sequences were close to Pontonema vulgate and Adoncholaimus sp., four to Daptonema procerus and two （identical） to Enoplus brews. Our results showed that free-living marine nematode diversities could be determined by PCR retrieving and analysis of the 18S rDNA sequences and an 18S rDNA sequence could be assigned to a species or a genus only if the 18S rDNA sequences of the free-living marine nematodes were accumulated to some extent. 相似文献
3.
The sulfate-reducing bacteria (SRB) community in the deep-sea sediments of the west Pacific Warm Pool (WP) was surveyed by molecular phylogenetic analyses using primers targeting the 16S rRNA gene fragments of SRB. Specific 16S rRNA gene libraries from five sediment layers (1-cm, 3-cm, 6-cm, 10-cm and 12-cm layer) of the 12-cm core of WP-0 were constructed. The clones in the five libraries were differentiated by restriction fragment length polymorphism (RFLP) and representative clones were selected to sequence. It was found that the clones fell into four groups, which were closest related to Desulfotomaculum, Desul- facinum, Desulfomonile and Desulfanuticus. Desulfacinum-like clones were only detected in the upper layers of the sediment core, whereas Desulfomonile-like clones were only present in the deeper layers. Fluorescence in situ hybridization (FISH) was further carried out to visualize and count the SRB and bacteria in the five sediment layers. It was found that SRB constituted only a small proportion of the bacteria community (0.34%-1.95%), it had the highest content in the 3-cm layer (1.95%) and had a depth- related decreasing tendency along the 12- cm core. 相似文献
4.
5.
以企鹅珍珠贝(Pteria penguin)闭壳肌为样品,利用高盐+十二烷基硫酸钠(SDS)除去蛋白和多糖,用低盐+十六烷基三甲基溴化铵(CTAB)进一步纯化DNA,建立一种贝类基因组DNA简便、安全、经济的提取方法。改进后的SDS-CTAB法提取的DNA纯度较高,无蛋白质和RNA污染;酶切和AFLP实验验证表明,所提取DNA可满足酶切分析和分子标记等实验的要求。 相似文献
6.
《中国海洋湖沼学报》2016,(1)
Gut microorganisms play an important role in the digestion of their host animals. The purpose of this research was to isolate and assess the enzyme-producing microbes from the Apostichopus japonicus gut. Thirty-nine strains that can produce at least one of the three digestive enzymes(protease,amylase,and cellulase) were qualitatively screened based on their extracellular enzyme-producing abilities. The enzyme-producing strains clustered into eight groups at the genetic similarity level of 100% by analyzing the restriction patterns of 16 S rDNA amplified with Mbo I. Phylogenetic analysis revealed that 37 strains belonged to the genus Bacillus and two were members of the genus Virgibacillus. Enzyme-producing capability results indicate that the main enzyme-producing microflora in the A. japonicus gut was Bacillus,which can produce protease,amylase,and cellulase. Virgibacillus,however,can only produce protease. The high enzyme-producing capability of the isolates suggests that the gut microbiota play an important role in the sea cucumber digestive process. 相似文献
7.
《山地科学学报》2020,17(7):1696-1711
Based on the precipitation data observed by stations and data simulated by 23 CMIP5 models, the features and future changes of summer(Jun-JulAug) extreme precipitation events in Sichuan Province of China were analysed. We found that the total precipitation(RSum), extreme precipitation threshold(Threshold90), extreme precipitation(TR90), extreme precipitation percentage(TR90 pct) and extreme precipitation intensity(TR90 str) decreased from the southeast to the northwest in Sichuan Province, reflecting the differences between eastern Sichuan(ESC, basins) and western Sichuan(WSC, mountains). Compared with the observations, most of the CMIP5 models showed that there were wet biases in WSC and an unclear bias pattern in ESC for the RSum, Threshold90, TR90, and TR90 str. However, the extreme precipitation days(ND90) and TR90 pct values simulated by the models were generally overestimated and underestimated,respectively. Compared with the historical period, most models showed obvious increases in the TR90 and TR90 pct in the 21 century, while the characteristics of Rsum, ND90, and TR90 str were inconspicuous. Compared with the mid-21 st century, the extreme precipitation in the late-21 st century exhibited a certain degree of increase. Even during the same period, the results of RCP8.5 were higher than those of RCP4.5, especially for the ND90, TR90, and TR90 pct. 相似文献
8.
Bacterial diversity in surface water of the Yellow Sea during and after a green alga tide in 2008 总被引：1，自引：0，他引：1
From May to August 2008, a large "green tide", consisting of the alga Ulva (Enteromorpha) prolifera, occurred in the Yellow Sea, China, affecting the local marine ecosystem and human activities. We investigated the influence of the green tide on the microbial community in the surface seawater, at four sites from July to August 2008, using bacterial 16S rRNA gene clone libraries. We sequenced 228 clones of unique patterns identified by restriction fragment length polymorphism (RFLP) techniques. The results show that 228 sequenced clones fell into six bacterial phyla:Proteobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia, Actinobacteria, and Planctomycetes. Alphaproteobacteria (33%), Gammaproteobacteria (25%), Bacteroidetes (23%) and Cyanobacteria (9%) dominated the assemblage. Comparison between samples collected in July (during the tide) and those collected in August (after the tide) showed that, in the microbial community, diversities of Alphaproteobacteria and Cyanobacteria increased after the tide, while those of Gammaproteobacteria and Bacteroidetes decreased. These results indicate that the green tide influenced the growth of some bacteria, and provide information for further studies on the interactions and relationships between U. prolifera and the bacterial community. This study suggests that microbial community analysis is a good approach to monitoring green tides. 相似文献
9.
Gut microorganisms play an important role in the digestion of their host animals. The purpose of this research was to isolate and assess the enzyme-producing microbes from the Apostichopus japonicus gut. Thirty-nine strains that can produce at least one of the three digestive enzymes (protease, amylase, and cellulase) were qualitatively screened based on their extracellular enzyme-producing abilities. The enzyme-producing strains clustered into eight groups at the genetic similarity level of 100% by analyzing the restriction patterns of 16S rDNA amplified with Mbo I. Phylogenetic analysis revealed that 37 strains belonged to the genus Bacillus and two were members of the genus Virgibacillus. Enzyme-producing capability results indicate that the main enzyme-producing microflora in the A. japonicus gut was Bacillus, which can produce protease, amylase, and cellulase. Virgibacillus, however, can only produce protease. The high enzyme-producing capability of the isolates suggests that the gut microbiota play an important role in the sea cucumber digestive process. 相似文献
10.
根据草鱼呼肠孤病毒(Grass Carp Reovirus,GCRV)的vp5基因设计特异性引物,并扩增其开放阅读框序列(open reading frame,ORF),然后连接至pGBKT7载体上构建酵母双杂交诱饵载体pGBKT7-vp5,转化至酵母菌Y2HGold,并进行PCR鉴定以及自激活性和毒性检测。PCR、酶切以及测序表明,pGBKT7-vp5重组诱饵载体构建成功。自激活性和毒性检测显示,阳性重组菌株pGBKT7-vp5/Y2HGold和阴性对照菌株pGBKT7/Y2HGold在SD/-Trp平板上出现大小相一致的乳白色菌落,且在SD/-Trp/X-α-Gel、SD/-Trp/AbA+/X-α-Gel平板上生长出蓝色菌落,而在SD/-Trp/-Ade/-His无菌落出现。表明重组菌株pGBKT7-vp5/Y2HGold表达的融合蛋白激活了报告基因AUR1-C和MEL1,没有激活报告基因ADE2和HIS3并且对宿主菌无毒性。该重组诱饵载体可用于酵母双杂交系统进一步筛选cDNA文库中与其相互作用的蛋白。 相似文献
11.
The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization (SSH) to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COΙ. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and COΙ so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster. 相似文献
12.
Effects of base analogues 5-bromouracil and 6-aminopurine on development of zebrafish Danio Rerio 总被引：1，自引：0，他引：1
Zebrafish （Danio rerio） genetic screens allow isolation of a wide array of problems in vertebrate biology. The effects of base analogues 5-bromouracil and 6-aminopurine on the development of zebrafish embryos are reported for the first time in this study. The early development of the zebrafish embryos was little affected by 5-bromouracil and 6-aminopurine, while the late development （organogenesis） was significantly impaired. Embryos exposed to 5-bromouracil mainly showed curled tail, wavy body, golden pigmentation and the mouth with protruding lower jaw. 6-aminopurine-treated embryos had defective anterior structures, curled tails and wavy body. RAPD analysis showed that the majority of 5-bromouracil-and 6-aminopurine-treated larvae and fish shared banding patterns in common with the control, suggesting that most mutagenesis induced by these agents are point mutations. However, some fish derived from 5-bromouracil-treated embryos had golden（gol） pigmentation; and RAPD analysis revealed that their band patterns differed from those of the control.Possibly, 5-bromouracil can occasionally cause relatively extensive changes in the fish genome. The results of this study may provide valuable help for detailed studies of mutagenesis. 相似文献
13.
《中国海洋湖沼学报》2020,(2)
Deep-sea organisms survive in an extremely harsh environment.There must be some genetic adaptation mechanisms for them.We systematically characterized and compared the complete mitochondrial genome(mitogenome) of a deep-sea crab(Chaceon granulates) with those of shallow crabs.The mitogenome of the crab was 16 126 bp in length,and encoded 37 genes as most of a metazoan mitogenome,including 13 protein-coding genes(PCGs),22 transfer RNA(tRNA) genes,and 2 ribosomal RNA(rRNA) genes.The gene arrangement and orientation was conserved in the crabs.However,a unique mitogenome element regulator,the origin of light-strand replication(O L),was firstly predicted in the present crab mitogenome.In addition,further positive selection analysis showed that two residues(33 S in ND3 and 502 I in ND5) in C.granulates mitogenome were positively selected,indicated the selective evolution of the deep-sea crab.Therefore,the mitogenome of deep-sea C.granulates showed a unique O_L element and positive selection.These special features would influence the mitochondrial energy metabolism,and be involved in the adaptation of deepsea environment,such as oxygen deficits and low temperatures. 相似文献
14.
A fragment of a large sub-unit ribosomal DNA (LrDNA) of 12 strains of Prorocentrum species was amplified by polymerase chain reaction (PCR). The PCR products were digested by 3 restriction endonucleases (Cfo Ⅰ, Hae Ⅲ, and RSA Ⅰ) and then resolved in agarose gels. Results show that different species had different RFLP patterns, except for P arcuatum (ME 131), which had the same pattern to P. micans (ME 160 and 04).The same fragment of 19 strains of the genus was also amplified and subjected to denaturing gradient gel electrophoresis (DGGE). 11 different patterns were resolved. Different cultures of a same species had the same pattern. The results of RFLP and DGGE analyses showed that eight newly isolated epibenthic Prorocentrum species were different from each other, and also from other cultured ones examined in this study. P arcuatum(MEI32) could not be differentiated from P. micans (MEI60 and 04), it was probably mis-identified, since they are quite different morphologically. P. redfieldii (MEI38) could also not be distinguished form P. triestinium(MEI32), it should be regarded as a synonym ofP. triestinium. Unexpectedly, a restriction site was found in P.micans, compared with previous sequence data. 相似文献
15.
16.
Zebrafish (Danio rerio) genetic screens allow isolation of a wide array of problems in vertebrate biology. The effects of base analogues 5-bromouracil
and 6-aminopurine on the development of zebrafish embryos are reported for the first time in this study. The early development
of the zebrafish embryos was little affected by 5-bromouracil and 6-aminopurine, while the late development (organogenesis)
was significantly impaired. Embryos exposed to 5-bromouracil mainly showed curled tail, wavy body, golden pigmentation and
the mouth with protruding lower jaw. 6-aminopurine-treated embryos had defective anterior structures, curled tails and wavy
body. RAPD analysis showed that the majority of 5-bromouracil- and 6-aminopurine-treated larvae and fish shared banding patterns
in common with the control, suggesting that most mutagenesis induced by these agents are point mutations. However, some fish
derived from 5-bromouracil-treated embryos had golden (gol) pigmentation; and RAPD analysis revealed that their band patterns differed from those of the control. Possibly, 5-bromouracil
can occasionally cause relatively extensive changes in the fish genome. The results of this study may provide valuable help
for detailed studies of mutagenesis.
This work was supported by Ministry of Science and Technology (MOST) of China (G 1999012005). 相似文献
17.
从近江牡蛎肠道中分离出21株菌,其中, 9株为革兰阳性菌, 12株革兰阴性菌。为寻找能分泌多种酶的有益微生物,研究了它们蛋白酶、脂肪酶、淀粉酶、纤维素酶的产酶能力。结果表明,有61 .9%的菌株能分泌蛋白酶或淀粉酶(各有13株菌);有52. 4%的菌株能分泌脂肪酶(11株菌);有33. 3%的菌株能产纤维素酶(7株菌)。在这21株菌中,产4种酶的有5株菌,产3种酶的3株菌,产两种酶的5株菌,产1种酶的3株菌,不产酶的仅有5株菌。不产酶的菌株仅占细菌总数的23. 8%,而各种产酶菌则高达76. 2%,由此表明细菌在近江牡蛎对食饵消化过程的重要性。 相似文献
18.
《中国海洋湖沼学报》2021,(3)
Spatial variations of sediment microbes pose a great challenge for the estimation of anthropogenic influence on biogeochemical processes, yet remain very unclear in coastal ecosystems. Surface sediments in 9 stations from the eutrophic Jiaozhou Bay, China, were sampled, DNA was extracted within the sediments, and the 16 S rDNA was sequenced with the Illumina Hiseq sequencing. Results reveal considerable heterogeneity of sediment bacteria in the Jiaozhou Bay, of which Proteobacteria and Bacteroidetes accounted for over 75%. Bacterial alpha-diversity indices decreased generally from the outside to the inner part of the bay and from the offshore to the nearshore area. Bacterial community structures of S3, S4, S7, and S8 clustered, those of S5, S13, and S14 grouped together, while those of S6 and S10 were distinct from each other and from those of the other stations. Major class Gammaproteobacteria were more abundant at the stations with mesoeutrophic to eutrophic levels(S4, S5, S8, and S10) and less abundant at oligotrophic stations(S6, S13, and S14), while Deltaproteobacteria had an opposite distribution pattern. Overall, bacterial community composition transitioned from being Xanthomonadales-dominant at S4 and S8 to being unidentifed_Gammaproteobacteria-dominant at S5, S6, S13, and S14, while in other stations there were comparable orders. The biogeochemical processes correspondingly changed from being nitrogen cycling-dominant at S4 and S8 to being sulfur cycling-dominant at S5, S6, S13, and S14. The bacterial distribution patterns were especially affected by the factors(dissolved organic phosphorus, DOP) in the overlying seawater due to the habitat status of P-insu fficiency in the bay. Both orders Xanthomonadales and Alteromonadales could serve as bioindicators of anthropogenic pollution to different pollution types. At last, divergent distribution patterns of individual bacterial populations in the bay were revealed, the influential environmental gradients were clarified, and the uncertainty of microbes was reduced, helping to predict environmental functions in coastal areas. 相似文献
19.
Analysis of SSRs Derived from an EST Library of Half-Smooth Tongue Sole Cynoglossus semilaevis 总被引：1，自引：0，他引：1
A complementary DNA (cDNA) library was constructed from half-smooth tongue sole spleen. A long-read expressed sequence tag (EST) database was generated, containing 3100 cDNA clones, of which 220 clones were fully sequenced. A total of 1060 non-redundant simple sequence repeats (SSRs) were obtained from the cDNA library. An average of 5 kb sequence generates 1 SSR in the half-smooth tongue sole spleen cDNA library. The proportion of the SSR unit size was different in the cDNA library. The monomeric repeats (51.4%) are the most abundant class of SSR in the dataset. The dimeric, trimeric, tetrameric and hexameric re- peats are represented in decreasing proportions of 27.2%, 16.0%, 2.8% and 1.9%, respectively. The frequency of pentameric repeats was observed the least (only 0.7%). Most of the monomeric and dimeric repeats are distributed in 3' and 5' un-translation region. If translation regions are considered merely, trimeric repeats are the highest, accounting for 57% of the total microsatellites. 相似文献
20.
A complementary DNA (cDNA) library was constructed from half-smooth tongue sole spleen. A long-read expressed sequence tag
(EST) database was generated, containing 3100 cDNA clones, of which 220 clones were fully sequenced. A total of 1060 non-redundant
simple sequence repeats (SSRs) were obtained from the cDNA library. An average of 5 kb sequence generates 1 SSR in the half-smooth
tongue sole spleen cDNA library. The proportion of the SSR unit size was different in the cDNA library. The monomeric repeats
(51.4%) are the most abundant class of SSR in the dataset. The dimeric, trimeric, tetrameric and hexameric repeats are represented
in decreasing proportions of 27.2%, 16.0%, 2.8% and 1.9%, respectively. The frequency of pentameric repeats was observed the
least (only 0.7%). Most of the monomeric and dimeric repeats are distributed in 3′ and 5′ un-translation region. If translation
regions are considered merely, trimeric repeats are the highest, accounting for 57% of the total microsatellites. 相似文献