The mitochondrial manganese superoxide dismutase gene in Chinese shrimp Fenneropenaeus chinensis: Cloning, distribution and expression

Manganese superoxide dismutase (MnSOD) plays an important role in crustacean immune defense reaction by eliminating oxidative stress. Knowledge on MnSOD at molecular level allows us to understand its regulatory mechanism in crustacean immune system. A novel mitochondrial manganese superoxide dismutase (mMnSOD) was cloned from hepatopancreas of Chinese shrimp Fenneropenaeus chinensis by 3' and 5' rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA consists of 1185 bp with a 660 bp open reading frame, encoding 220 amino acids. The deduced amino acid sequence contains a putative signal peptide of 20 amino acids. Sequence comparison showed that the mMnSOD of F. chinensis shares 88% and 82% identity with that of giant freshwater prawn Macrobrachium rosenbergii and blue crab Callinectes sapidus, respectively. mMnSOD transcripts were detected in hepatopancreas, hemocytes, lymphoid organ, intestine, ovary, muscle and gill by Northern blotting. RT-PCR analysis indicated that mMnSOD showed different expression profiles in shrimp hemocytes and hepatopancreas after artificial infection with while spot syndrome virus (WSSV). In addition, a fusion protein containing mMnSOD was produced in vitro. LC-ESI-MS analysis showed that two peptide fragments (-GDVNTVISLAPALK- and -NVRPDYVNAIWK-) of the recombinant protein were identical to the corresponding sequence of M. rosenbergii mMnSOD, and the enzyme activity of the refolded recombinant protein was also measured. (c) 2006 Elsevier Ltd. All rights reserved.

Distribution and their pollution assessment of heavy metals in the sediments of the Yalu River Estuary and its adjacent coastal waters

The present paper deals with the distribution patterns of heavy metals and the associated influencing factors in the Yalu River Estuary and its adjacent coastal waters. Based upon the analysis of the surficial and core sediments measurements, the pollution of heavy metal and potential ecological risk were evaluated. The burial flux and contents of heavy metals (except for copper) have been continuously increasing since the 1920s. Therefore, the gross potential ecological risk for the sediments was high or very high, and the study area was endangered by heavy metals contamination. Heavy metals originated mainly from upstream pollutant input, correlation analysis showed that chromium, nickel, zinc, cadmium, lead, arsenic, and mercury in the sediments of the middle and west channels as well as the sea area of the western Yalu River Estuary concentrations were most probably derived from similar sources. In contrast, the metal of copper most probably originated from sources different from the other metals. Preliminary studies indicate that copper contamination was most likely the result of emission from mining activities situated at the upstream of the river. The contents of heavy metals in the sediments of estuarine turbidity maximum zone of Yalu River were larger than those of any other areas in the middle channel. With large portion of fine sediments, weaker hydrodynamics, and richer sources of heavy metals, the sediments of the west channel, were even more enriched with heavy metals than those of the middle channel.

Distribution and mobility of metals in agricultural soils near a copper smelter in South China

The distribution and mobility of heavy metals in the paddy soils surrounding a copper smelting plant in south China was investigated. We assessed the degree of metal contamination using an index of geoaccumulation. The metals were divided into two groups: (1) Cu, Zn, Pb and Cd, whose concentrations were heavily affected by anthropogenic inputs, and (2) Ni, Co and Cr, which were mainly of geochemical origin. Concentrations of Cu, Cd, Zn, and Pb in the polluted soils were higher than the Chinese soil quality criteria. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the residual and NH2OH HCl extractable fractions. In contrast, Cd was predominantly associated with the MgCl2 extractable fraction. A large proportion of Cu was bound to the acidic H2O2 extractable fractions, while Zn was predominantly found in the residual phase. The fraction of mobile species, which potentially is the most harmful to the environment, was found to be elevated compared to unpolluted soils in which heavy metals are more strongly bound to the matrix. The mobility of the metals was studied by water extraction using a modification of Tessier's procedure, and the order of mobility was Zn > Cd > Cu > Ce > Pb.

A quasi-synoptic interpretation of water mass distribution and circulation in the western North Pacific II: Circulation

Using the data of conductivity-temperature-depth (CTD) intensive observations conducted during Oct.-Nov. 2005, this study provides the first three-dimension quasi-synoptic description of the circulation in the western North Pacific. Several novel phenomena are revealed, especially in the deep ocean where earlier observations were very sparse. During the observations, the North Equatorial Current (NEC) splits at about 12A degrees N near the sea surface. This bifurcation shifts northward with depth, reaching about 20A degrees N at 1 000 m, and then remains nearly unchanged to as deep as 2 000 m. The Luzon Undercurrent (LUC), emerging below the Kuroshio from about 21A degrees N, intensifies southward, with its upper boundary surfacing around 12A degrees N. From there, part of the LUC separates from the coast, while the rest continues southward to join the Mindanao Current (MC). The MC extends to 2 000 m near the coast, and appears to be closely related to the subsurface cyclonic eddies which overlap low-salinity water from the North Pacific. The Mindanao Undercurrent (MUC), carrying waters from the South Pacific, shifts eastward upon approaching the Mindanao coast and eventually becomes part of the eastward undercurrent between 10A degrees N and 12A degrees N at 130A degrees E. In the upper 2 000 dbar, the total westward transport across 130A degrees E between 7.5A degrees N and 18A degrees N reaches 65.4 Sv (1 Sv = 10(-6) m(3)s(-1)), the northward transport across 18A degrees N from Luzon coast to 130A degrees E is up to 35.0 Sv, and the southward transport across 7.5A degrees N from Mindanao coast to 130A degrees E is 27.9 Sv.

A quasi-synoptic interpretation of water mass distribution and circulation in the western North Pacific: I. Water mass distribution

With high-resolution conductivity-temperature-depth (CTD) observations conducted in Oct.-Nov. 2005, this study provides a detailed quasi-synoptic description of the North Pacific Tropic Water (NPTW), North Pacific Intermediate Water (NPIW) and Antarctic Intermediate Water (AAIW) in the western North Pacific. Some novel features are found. NPTW enters the western ocean with highest-salinity core off shore at 15 degrees-18 degrees N, and then splits to flow northward and southward along the western boundary. Its salinity decreases and density increases outside the core region. NPIW spreads westward north of 15 degrees N with lowest salinity off shore at 21 degrees N, but mainly hugs the Mindanao coast south of 12 degrees N. It shoals and thins toward the south, with salinity increasing and density decreasing. AAIW extends to higher latitude off shore than that in shore, and it is traced as a salinity minimum to only 10 degrees N at 130 degrees E. Most of the South Pacific waters turn northeastward rather than directly flow northward upon reaching to the Mindanao coast, indicating the eastward shift of the Mindanao Undercurrent (MUC).

Distribution and species diversity of plant communities along transect on the Northeastern Tibetan plateau

The distribution and species diversity of plant communities along a 600 km transect through the northeastern Tibetan Plateau (32 degrees 42'-35 degrees 07' N, 101 degrees 02'-97 degrees 38' E) with altitudes from 3255 to 4460 m are described. The transect started from the Youyi Bridge of Banma through Dari, Maqin and Maduo to Zaling Lake. The data from 47 plots along the transect are summarized and analyzed. The mean annual temperature, the mean annual rainfall and the length of growing season decreases from 2.6 to -4.5 degrees C, from 767.2 to 240.1 mm, from 210 to 140 days, respectively, along the transect from the southeastern Banma to northwestern Zaling Lake. The number of vascular plant species recorded in 47 plots is 242 including 2 tree, 34 shrub, 206 herb species. Main vegetation types on the transect from southeast to northwest are: Sabina convallium forest, Picea likiangensis forest, Pyracantha fortuneana + Spiraea alpina shrub, Hippophae neurocarpu shrub, Sibiraea angustata + Polygonum viviparum shrub, Stellera chamaejasme herb meadow, Potentilla fruticosa + Salix obscura + Carex sp. Shrub, Kobresia capillifolia meadow, P. froticosa + Kobresia humilis shrub, Caragana jubata + S. obscura shrub, Kobresia tibetica meadow, Kobresia pygmaea meadow, K. pygmaea + Stipa purpurea steppe meadow, Stipa purpurea steppe. Plant richness and diversity index all showed a decreasing trend with increasing of elevation along transect from southeast to northwest. Detailed information on altitudinal ranges and distribution of the alpine vegetation, vascular flora and environments over the alpine zone at northeastern Tibetan Plateau provides baseline records relevant to future assessment of probable effects of global climate changes.