Expression pattern of dmrt4 from olive flounder (Paralichthys olivaceus) in adult gonads and during embryogenesis

The dmrt (doublesex and mab-3 related transcription factor) gene family comprises several transcription factors that share a conserved DM domain. Dmrt1 is considered to be involved in sexual development, but the precise function of other family members is unclear. In this study, we isolated genomic DNA and cDNA sequences of dmrt4, a member of the dmrt gene family, from olive flounder, Paralichthys olivaceus, through genome walking and real-time reverse transcriptase (RT)-PCR. Sequence analysis indicated that its genomic DNA contains two exons and one intron. A transcriptional factor binding sites prediction program identified a sexual development-related protein, Sox9 (Sry-like HMG box containing 9) in its 5' promoter. Protein alignment and phylogenetic analysis suggested that flounder Dmrt4 is closely related to tilapia Dmo (DM domain gene in ovary). The expression of dmrt4 in adult flounder was sexually dimorphic, as shown by real-time RT-PCR analysis, with strong expression in the testis but very weak expression in the ovary. Its expression was also strong in the brain and gill, but there was only weak or no expression at all in some of the other tissues tested of both sexes. During embryogenesis, its expression was detected in most developmental stages, although the level of expression was distinctive of the various stages. Whole mount in situ hybridization revealed that the dmrt4 was expressed in the otic placodes, forebrain, telencephalon and olfactory placodes of embryos at different developmental stages. These results will improve our understanding of the possible role of flounder dmrt4 in the development of the gonads, nervous system and sense organs.

A fibrinogen-related protein from bay scallop Argopecten irradians involved in innate immunity as pattern recognition receptor

The family of fibrinogen-related proteins (FREPs) is a group of proteins with fibrinogen-like domains. Many members of this family play important roles as pattern recognition receptors in innate immune responses. The cDNA of bay scallop Argopecten irradians FREP (designated as AiFREP) was cloned by rapid amplification of cDNA ends (RACE) method based on the expressed sequence tag (EST). The full-length cDNA of AiFREP was of 990 bp. The open reading frame encoded a polypeptide of 251 amino acids, including a signal sequence and a 213 amino acids fibrinogen-like domain. The fibrinogen-like domain of AiFREP was highly similar to those of mammalian ficolins and other FREPs. The temporal expression of AiFREP mRNA in hemolymph was examined by fluorescent quantitative real-time PCR. The mRNA level of scallops challenged by Listonella anguillarum was significantly up-regulated, peaked to 9.39-fold at 9 h after stimulation, then dropped back to 4.37-fold at 12 h, while there was no significant change in the Micrococcus luteus challenged group in all periods of treatment. The function of AiFREP was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli Rosetta gami (DE3). The recombinant AiFREP (rAiFREP) agglutinated chicken erythrocytes and human A, B, O-type erythrocytes. The agglutinating activities were calcium-dependent and could be inhibited by acetyl group-containing carbohydrates. rAiFREP also agglutinated Gram-negative bacteria E. coli JM109, L anguillarum and Gram-positive bacteria M. luteus in the presence of calcium ions. These results collectively suggested that AiFREP functions as a pattern recognition receptor in the immune response of bay scallop and contributed to nonself recognition in invertebrates, which would also provide clues for elucidating the evolution of the lectin pathway of the complement system. (C) 2008 Elsevier Ltd. All rights reserved.

Three-stage transformation of chlorophyll transient fluorescence pattern under sustained dehydration and the discovery of critical water content in seaweeds

The chlorophyll fluorescence kinetics of marine red alga Grateloupia turutunt Yamada, green alga Ulva pertusa Kjellm and brown alga Laminaria japonica Aresch during natural sustained dehydration were monitored and investigated. The pulse amplified modulation (PAM) system was used to analyze the distinct fluorescence parameters during thallus dehydration. Results proved that the fluorescence kinetics of different seaweed all showed three patterns of transformation with sustained water loss. These were: 1) peak kinetic pattern (at the early stage of dehydration fluorescence enhanced and quenched subsequently, representing a normal physiological state). 2) plateau kinetic pattern (with sustained water loss fluorescence enhanced continuously but quenching became slower, finally reaching its maximum). 3) Platform kinetic pattern (fluorescence fell and the shape of kinetic curve was similar to plateau kinetic pattern). A critical water content (CWC) could be found and defined as the percentage of water content just prior to the fluorescence drop and to be a significant physiological index for evaluation of plant drought tolerance. Once thallus water content became lower than this value the normal peak pattern can not be recovered even through rehydration, indicating an irreversible damage to the thylakoid membrane. The CWC value corresponding to different marine species were varied and negatively correlated with their desiccation tolerance, for example. Laminaria japonica had the highest CWC value (around 90%) and the lowest dehydration tolerance of the three. In addition, a fluorescence "burst" was found only in red algae during rehydration. The different fluorescence parameters F-o, F-v and F-v, F-m were measured and compared during water loss. Both F-o and F-v increased in the first stage of dehydration but F-v/F-m. kept almost constant. So the immediate response of in vivo chlorophyll fluorescence to dehydration was an enhancement. Later with sustained dehydration F-o increased continuously while F-v decreased and tended to become smaller and smaller. The major changes in fluorescence (including fluorescence drop during dehydration and the burst during rehydration) were all attributed to the change in F-o instead of F-v This significance of F-o indicates that it is necessary to do more research on F-o as well as on its relationship with the state of thylakoid membrane.

Early expressed genes showing a dichotomous developing pattern in the lancelet embryo

Lancelets (amphioxus), although showing the most similar anatomical features to vertebrates, never develop a vertebrate-like head but rather several structures specific to this animal. The lancelet anatomical specificity seems to be traceable to early developmental stages, such as the vertebrate dorsal and anterior-posterior determinations. The BMP and Wnt proteins play important roles in establishing the early basis of the dorsal structures and the head in vertebrates. The early behavior of BMP and Wnt may be also related to the specific body structures of lancelets. The expression patterns of a dpp-related gene, Bbbmp2/4, and two wnt-related genes, Bbwnt7 and Bbwnt8, have been studied in comparison with those of brachyury and Hnf-3 beta class genes The temporal expression patterns of these genes are similar to those of vertebrates; Bbbmp2/4 and Bbwnt8 are first expressed in the invaginating primitive gut and the equatorial region. respectively, at the initial gastrula stage. However, spatial expression pattern of Bbbmp2/4 differs significantly from the vertebrate cognates. It is expressed in the mid-dorsal inner layer of gastrulae and widely in the anterior region, in which vertebrates block BMP signaling, The present study suggests that the lancelet embryo may have two distinct developmental domains from the gastrula stage, the domains of which coincide later with the lateral diverticular and the somitocoelomic regions. The embryonic origin of the anterior-specific structures in lancelets corresponds to the anterior domain where Bbbmp2/4 is continuously expressed.

A Dicer-1 gene from white shrimp Litopenaeus vannamei: Expression pattern in the processes of immune response and larval development

Dicer is a member of the RNAase III family which catalyzes the cleavage of double-stranded RNA to small interfering RNAs and micro RNAs, and then directs sequence-specific gene silencing. In this paper, the full-length cDNA of Dicer-1 was cloned from white shrimp Litopenaeus vannamei (designated as LvDcr1). It was of 7636 bp, including a poly A tail, a 5' UTR of 136 bp, a 3' UTR of 78 bp, and an open reading frame (ORF) of 7422 bp encoding a putative protein of 2473 amino acids. The predicted amino acid sequence comprised all recognized functional domains found in other Dicer-1 homologues and showed the highest (97.7%) similarity to the Dicer-1 from tiger shrimp Penaeus mondon. Quantitative real-time PCR was employed to investigate the tissue distribution of LvDcr1 mRNA, and its expression in shrimps under virus challenge and larvae at different developmental stages. The LvDcr1 mRNA could be detected in all examined tissues with the highest expression level in hemocyte, and was up-regulated in hemocytes and gills after virus injection. These results indicated that LvDcr1 was involved in antiviral defense in adult shrimp. During the developmental stages from fertilized egg to postlarva VII, LvDcr1 was constitutively expressed at all examined development stages, but the expression level varied significantly. The highest expression level was observed in fertilized eggs and followed a decrease from fertilized egg to nauplius I stage. Then, the higher levels of expression were detected at nauplius V and postlarva stages. LvDcr1 expression regularly increased at the upper phase of nauplius, zoea and mysis stages than their prophase. The different expression of LvDcr1 in the larval stages could provide clues for understanding the early innate immunity in the process of shrimp larval development. (C) 2010 Elsevier Ltd. All rights reserved.

Broader pattern of tandem repeats in the mitochondrial control region of Perciformes

Perciformes, the largest order of vertebrates with 20 suborders, is the most diverse fish order that dominates vertebrate ocean life. The complete mitochondrial control region (CR) of Trichiurus japonicus (Trichiuridae, Scombroidei) and Pampus sp. (Stromateidae, Stromateoidei) were amplified and sequenced. Together with data from GenBank, the tandem repeats in the mitochondrial CR from 48 species, which covered nine suborders of Perciformes, are reported in this study. The tandem repeats tend to be long in the suborder Percoidei and Stromateoidei. The identical repeats in 21 species of Cichlidae suggest a common origin and have existed before species divergence. Larimichthys crocea shows tandem repeats instead of the typical structure of the central conserved sequence blocks, which was first reported in Perciformes and vertebrates. This might have resulted from interruption of the polymerase activity during the H-strand synthesis. The four broader patterns presented here for the tandem repeats, including those in both the 5' and 3' ends, only in the either 5' or 3' end, and in the central conserved domain of the control region, will be useful for understanding the evolution of species.

CfLGBP, a pattern recognition receptor in Chlamys farreri involved in the immune response against various bacteria

Lipopolysaccharide and beta-1, 3-glucan binding protein (LGBP) is a kind of pattern recognition receptor, which can recognize and bind LPS and beta-1, 3-glucan, and plays curial roles in the innate immune defense against Gram-negative bacteria and fungi. In this study, the functions of LGBP from Zhikong scallop Chlamys farreri performed in innate immunity were analyzed. Firstly, the mRNA expression of CfLGBP in hemocytes toward three typical PAMPS stimulation was examined by realtime PCR. It was up-regulated extremely (P < 0.01) post stimulation of LPS and beta-glucan, and also exhibited a moderate up-regulation (P < 0.01) after PGN injection. Further PAMPs binding assay with the polyclonal antibody specific for CfLGBP proved that the recombinant CfLGBP (designated as rCfLGBP) could bind not only LPS and beta-glucan, but also PGN in vitro. More importantly, rCfLGBP exhibited obvious agglutination activity towards Gram-negative bacteria Escherichia coil, Gram-positive bacteria Bacillus subtilis and fungi Pichia pastoris. Taking the results of immunofluorescence assay into account, which displayed CfLGBP was expressed specifically in the immune cells (hemocytes) and vulnerable organ (gill and mantle), we believed that LGBP in C farreri, serving as a multi-functional PRR, not only involved in the immune response against Gram-negative and fungi as LGBP in other invertebrates, but also played significant role in the event of anti-Gram-positive bacteria infection. As the first functional research of LGBP in mollusks, our study provided new implication into the innate immune defense mechanisms of C. farreri and mollusks. (C) 2010 Elsevier Ltd. All rights reserved.

Cflec-5, a pattern recognition receptor in scallop Chlamys farreri agglutinating yeast Pichia pastoris

C-type lectins are a superfamily of carbohydrate-recognition proteins which play crucial roles as pattern recognition receptors (PRRs) in the innate immunity. In this study, the full-length cDNA of a C-type lectin was cloned from scallop Chlamys farreri (designated as Cflec-5) by expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach The full-length cDNA of Cflec-5 was of 1412 bp. The open reading frame encoded a polypeptide of 153 amino acids, including a signal sequence and a conserved carbohydrate-recognition domain with the EPN motif determining the mannose-binding specificity The deduced amino acid sequence of Cflec-5 showed high similarity to members of C-type lectin superfamily. The quantitative real-time PCR was performed to investigate the tissue distribution of Cflec-5 mRNA and its temporal expression profiles in hemocytes post pathogen-associated molecular patterns (PAMPs) stimulation. In healthy scallops, the Cflec-5 mRNA was mainly detected in gill and mantle, and marginally in other tissues The mRNA expression of Cflec-5 could be significantly induced by lipopolysaccharide (LPS) and glucan stimulation and reached the maximum level at 6 h and 12 h, respectively But its expression level did not change significantly during peptidoglycan (PGN) stimulation The function of Cflec-5 was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli Rosetta Gami (DE3) The recombinant Cflec-5 agglutinated Pichia pastoris in a calcium-independent way The agglutinating activity could be inhibited by D-mannose. LPS and glucan, but not by D-galactose or PGN. These results collectively suggested that Cflec-5 was involved in the innate Immune response of scallops and might contribute to nonself-recognition through its interaction with various PAMPs (C) 2010 Elsevier Ltd All rights reserved

Tectonic and geodynamic pattern of marginal seas on the West Pacific inferred from multi-satellite altewetry geoid

With the rapid development of satellite observations, we can use the altimetry geoid to study submarine tectonics and geodynamics. On the basis of the 4' x 4' geoid undulation calculated from altimeter data of Geosat, ERS-1/2 and Topex/Poseidon on the West Pacific, located between 0degreesN similar to 45degreesN, 100degreesC similar to 150degreesE, Bouguer, Glenni and isostatic geoid undulation are obtained from correction of gravitational potential of the global topography and isostacy. Moho discontinuity depth is inversed by the Glenni geoid undulation, and the stress field from small-scale mantle convection is reasonably calculated from the isostatic geoid undulation. The results show that within the Philippine Sea and the South China Sea, short-wavelength lineations of the geoid undulation are parallel or cross to magnetic lineations and rifting ridges. The Moho depth of marginal sea basins becomes shallow southward, and its values are similar to that of the Philippine Sea. These facts show that strength of tectonic activities are almost the same on the both sides of the Ryukyu-Taiwan-Philippine are. Various kinds of tectonic features with different driving mechanisms of small-middle and large-scale of mantle convection, however, display a special pattern of tectonics and geodynamics of the continental marginal seas distinguished from oceans and continents.

Effects of body size and water temperature on food consumption and growth in the sea cucumber Apostichopus japonicus (Selenka) with special reference to aestivation

To investigate the effects of body size and water temperature on feeding and growth in the sea cucumber Apostichopus japonicus (Selenka), the maximum rate of food consumption in terms of energy (C-maxe; J day(-1)) and the specific growth rate in terms of energy (SGRe; % day(-1)) in animals of three body sizes (mean +/- SE) - large (134.0 +/- 3.5 g), medium (73.6 +/- 2.2 g) and small (36.5 +/- 1.2 g) - were determined at water temperatures of 10, 15, 20, 25 and 30 degrees C. Maximum rate of food consumption in terms of energy increased and SGRe decreased with increasing body weight at 10, 15 and 20 degrees C. This trend, however, was not apparent at 25 and 30 degrees C, which could be influenced by aestivation. High water temperatures (above 20 degrees C) were disadvantageous to feeding and growth of this animal; SGRe of A. japonicus during aestivation was negative. The optimum temperatures for food consumption and for growth were similar and were between 14 and 15 degrees C, and body size seemed to have a slight effect on the optimal temperature for food consumption or growth. Because aestivation of A. japonicus was temperature dependent, the present paper also documented the threshold temperatures to aestivation as indicated by feeding cessation. Deduced from daily food consumption of individuals, the threshold temperature to aestivation for large and medium animals (73.3-139.3 g) was 24.5-25.5 degrees C, while that for small animals (28.9-40.7 g) was between 25.5 and 30.5 degrees C. These values are higher than previous reports; differences in sign of aestivation, experimental condition and dwelling district of test animals could be the reasons.

Distribution pattern of marine flagellate and its controlling factors in the central and north part of the Huanghai Sea in early summer

A survey was carried out in the central and north part of the Huanghai Sea (34.5degrees similar to 37.0degreesN, 120.5degrees similar to124.0degreesE) during June 12 similar to 27, 2000. It was found that the abundance of marine flagellate ranged from 45 to 1278 cell/ml, 479 cell/ml in average. Flagellate was more abundant in the central part than in the north part of Huanghai Sea, and the abundance decreased with the increasing distance from the coast, showing a similar distribution pattern with isotherm. Vertically, high density of flagellate was always presented in the bottom of thermocline, and formed a dense accumulation in the central area of the Huanghai Sea Cold Water Mass. The effects of physical and biological factors on the distribution of marine flagellate in early summer were discussed. Water temperature (especially the existence of thermocline) rather than salinity showed significant effect on the distribution pattern of marine flagellate in the Huanghai Sea in early summer. When comparing the abundance of marine flagellate with that of other microorganisms, it revealed a comparatively stable relationship among these organhisms, with a ratio of heterotrophic bacteria: cyanobacteria: flagellate: dinoflagellate: ciliate being 10(5) 10(3):10(2):10(1):10(0).

Preliminary study of the dynamic origin of the distribution pattern of bottom sediments on the continental shelves of the Bohai Sea, Yellow Sea and East China Sea

The bottom sediment types in the Bohai Sea, Yellow Sea and East China Sea (BYECS) are diversified, and their distribution pattern is very complicated. However, the bottom sediment types can be simplified to be sandy sediment, clayey sediment and mixed sediment, which comprise the complicated distribution pattern of bottom sediment in the BYECS. The continental shelves of the BYECS are broad, with shallow water depths and tidal currents which are permanent and dominate the marine dynamics in the BYECS. Based on numerical simulation of tidal elevations and currents in the BYECS, the rates of suspended load transport and bed load transport during a single tidal cycle for sediments of eight different grain size ranges are calculated. The results show that any sediment, whose threshold velocity is less than that of tidal current, has the same transport trend. Suspended load transport rare, bed load transport rate, and the ratio of the former to the latter decrease with grain size becoming coarser and coarser. The erosion/accretion patterns of sediments with different grain sizes are determined by the sediment transport rate divergences, and the results show that the patterns are the same for sediments with different grain sizes. Three main bottom sediment types, i.e. sandy sediment mainly composed of fine sand, clayey sediment mainly composed of silty clay, and mixed sediment mainly composed of fine sand, silt, and clay, are obtained by computation. The three bottom sediment types and their distribution pattern are consistent not only with sediment transport field and the sea bed erosion/accretion pattern obtained by simulation, but also with field data of bottom sediment types and divisions. In the BYECS, sand ridges form mainly in the areas with strong rectilinear tidal currents, sand sheets form mainly in the areas dominated by strong rotatory tidal currents, and clayey sediments, i.e. mud patches, form mainly in the areas with weak tidal currents. Hence, not only the sandy sediments but also the clayey sediments in the BYECS are formed under the control of the whole tidal current field of the BYECS. The three main bottom sediment types are not isolated respectively-in fact, they constitute a whole tidal depositional system. Under the condition with no cyclonic cold eddy, the clayey sediments in the BYECS can form in weak tidal current environments. Therefore, a cold eddy is not necessary for the deposition of clayey sediments in the BYECS. (C) 2000 Academic Press.

三维VSP技术的研究及应用

Today, because of high petroleum consumption of our country, society steady development and difficulty increase in new resources exploration, deep exploitation of the existing oilfield is needed. More delicate reservoir imaging and description, such as thin layer identification, interlayer exploitation monitoring, subtle structure imaging, reservoir anisotropy recognition, can provide more detail evidence for new development adjustment scheme and enhanced oil recovery. Now, the people have already realized the 3D VSP technique more effective than the general methods in solving these aspects. But VSP technique especially 3D VSP develop slowly due to some reasons. Carrying out the research of VSP technique, it will be very useful to the EOR service. 3D VSP techniques include acquisition、data processing and interpretation. In this paper, the author carried out some researches around acquisition and processing. The key point of acquisition is the survey design, it is critical to the quality of the data and it will influence the reservoir recognition as follows. The author did detailed researches on the layout pattern of shot point and geophone. Some attributes relate to survey design such as reflectivity, incidence angle, observation area, reflection points distribution, fold, minimum well source distance, azimuth angle and so on are studied seriously. In this geometry design of 3D-VSP exploration in deviated wells, the main problems to be solved are: determining the center position of shots distribution, the effect of shots missing on coverage areas and coverage times，locating the shots and receivers of multi-wells. Through simulating and analyzing, the above problems are discussed and some beneficial conclusions are drawn. These will provide valuable references to actual survey design. In data processing, researches emphasize on those relatively key techniques such as wavefield separation, VSP-CDP imaging, the author carried out deep researches around these two aspects. As a result, variant apparent slowness wavefield separation method developed in this article suit the underground variant velocity field and make wavefield separation well, it can overcome reflection bending shortage aroused by conventional imaging method. The attenuateion range of underground seismic wave is very important for amplitude compensation and oil/gas identification.In this paper, seismic wave attenuateion mechanism is studied by 3D-VSP simulateion and Q-inversion technique. By testing with seismic data, the method of VSP data attenuateion and relationship of attenuateion attribute variant with depth is researched. Also the software of survey design and data processing is developed, it fill the gap of VSP area in our country. The technique developed applied successfully in SZXX-A Oilfield、QKYY-B Oilfield、A area and B area. The good results show that this research is valuable, and it is meaningful to the VSP technique development and application of offshore oil industry and other areas in our country.

黄东海及朝鲜海峡冰后期陆架沉积物的环境磁学研究

There are four chapters in this dissertation. The first chapter briefly synthesizes the basic theories, methods and present-day applying situation of environmental magnetism. The second chapter probes into the magnetic mineral diagenesis in the post-glacial muddy sediments from the southeastern South Yellow Sea and its response to marine environmental changes, using the muddy sediment of Core YSDP103 formed in the shelf since about 13 ka BP. The third chapter illustrates the high-resolution early diagenetic processes by investigating the rapidly deposited muddy sediments during the last 6 ka in Cores SSDP-102 and SSDP-103 from the near-shore shelf of Korea Strait. The fourth chapter presents the results of detailed rock magnetic investigation of the surface sediments from the fine-grained depositional area on the outer shelf of the East China Sea in an attempt to provide environmental magnetic evidence for the provenance of the fine-grained deposit. Core YSDP103 was retrieved in the muddy deposit under the cold eddy of the southeastern South Yellow Sea, and the uppermost 29.79 m core represents the muddy sediments formed in the shelf since about 13 ka BP. The lower part from 29.79 to 13.35 m, called Unit A2, was deposited during the period from the post-glacial transgression to the middle Holocene (at about 6 ~(14)C ka BP) when the rising sea level reached its maximum, while the upper part above 13.35 m (called Unit Al) was deposited in a cold eddy associated with the formation of the Yellow Sea Warm Current just after the peak of post-glacial sea level rise. For the the uppermost 29.79 m core, detailed investigation of rock-magnetic properties and analyses of grain sizes and geochemistry were made. The experimental results indicate that the magnetic mineralogy of the core is dominated by magnetite, maghemite and hematite and that, except for the uppermost 2.35 m, the magnetic minerals were subject to reductive diagenesis leading to significant decline of magnetic mineral content and the proportion of low-coercivity component. More importantly, ferrimagnetic iron sulphide (greigite) is found in Unit A2 but absent in Unit Al, suggesting the control of marine environmental conditions on the magnetic mineral diagenesis. Magnetic parameters show abrupt changes across the boundary between the Unit Al and A2, which reflects a co-effect of environmental conditions and primary magnetic components of the sediments on the diagenesis. Alternating zones of high and low magnetic parameters are observed in Unit A2 of Core YSDP103, which is presumably due to periodic changes of the concentration and/or grain size of magnetic minerals carried into the study area. Cores SSDP-102 and SSDP-103, two studied sediment cores from the Korea Strait contain mud sequences (14 m and 32.62 m in thickness) that were deposited during the last 6,000 years. Analyses of grain sizes and geochemistry of the cores have demonstrated that the sediments have uniform lithology and geochemical properties, however, marked down-core changes in magnetic properties suggest that diagenesis has significantly impacted the magnetic properties. An expanded view of early diagenetic reactions that affect magnetic mineral assemblages is evident in these rapidly deposited continental shelf sediments compared to deep-sea sediments. The studied sediments can be divided into four descending intervals, based on magnetic property variations. Interval 1 is least affected by diagenesis and has the highest concentrations of detrital magnetite and hematite, and the lowest solid-phase sulfur contents. Interval 2 is characterized by the presence of paramagnetic pyrite and sharply decreasing magnetite and hematite concentrations, which suggest active reductive dissolution of detrital magnetic minerals, the absolute minimum abundance of magnetite is reached at the end of this interval. Interval 3 is marked by a progressive loss of hematite with depth, and at the base of this interval, 82% to 88% of the hematite component was depleted and the bulk magnetic mineral concentration was reduced to the lowest value in the entire studied mud section. Interval 4 has an increasing down-core enhancement of authigenic greigite, which is interpreted to have formed due to arrested pyritization resulting from consumption of pore water sulfate with depth. This is the first clear demonstration from an active depositional environment for a delay of thousands of years for acquisition of a magnetization carried by greigite. This detailed view of diagenetic processes in continental shelf sediments suggests that studies of geomagnetic field behavior from such sediments should be conducted with care. Paleoceanographic and paleoclimatic studies based on the magnetic properties of shelf sediments with high sedimentation rates like those in the Korea Strait are also unlikely to provide a meaningful signature associated with syn-depositional environmental processes. The rock magnetic properties of the surface sediments from the fine-grained depositional area on the outer shelf of the East China Sea, an area surrounded by sands, are investigated with a view to providing information on the sediment provenance. Multiple magnetic parameters such as magnetic susceptibility (%), anhysteretic remanent magnetization (ARM), saturation rernanent magnetization (SIRM), coercivities of SIRM (Her), and S ratios (relative abundance of low-coercivity magnetic minerals) are measured for all 179 surface samples, and partial representative samples are examined for their magnetic hysteresis parameters, temperature-dependence of magnetic susceptibility and x-ray diffraction spectra. Our research indicates that the magnetic mineralogy is dominated by magnetite with a small amount of hematite and is primarily of pseudo-single domain (PSD) to multidomain (MD) nature with a detrital origin. In the surface sediments, the granulometry of magnetic fractions is basically independent of grain sizes of the sediment containing the magnetic grains, and the composition of magnetic minerals remains almost homogeneous, that is, with a relatively constant ratio of low to high coercivity fraction throughout the area. The magnetic concentration in the study area generally decreases to the east or southeast accompanied by magnetic-particle fining to the east or to the northeast. The geographic pattern of magnetic properties is most reasonably explained by a major source of sediment jointly from the erosion of the old Huanghe River deposit and the discharge of the Changjiang River. The rock magnetic data facilitate understanding of the transport mechanism of fine-grained sediments in the outer shelf of the East China Sea.