Cloning, Expression and Characterization of Translationally Controlled Tumor Protein （TCTP） Gene from Flatfish Turbot （Scophthalmus maximus）

A full-length cDNA encoding translationally controlled tumor protein of marine flatfish turbot (Scophthalmus maximus), SmTCTP, was isolated with rapid amplification of cDNA Ends (RACE). SmTCTP consisted of a 5' untranslated region (UTR) of 84 bp, a 3' UTR of 451 bp and an open reading flame (ORF) of 513 bp, encoding a protein of 170 amino acid residues, which contained two signature sequences of TCTP family. The 5'UTR of SmTCTP started with a 5'-terminal oligopyrimidine tract (5'-TOP), a typical feature for translationaily controlled mRNAs. The deduced amino acid sequence of SmTCTP was similar to the other known verte-brate TCTPs in a range of 58.8% to 64.1%. The length offish TCTPs was diverse among species, e.g., TCTP of turbot and sea perch (Lateolabrax japonicus) is 170 aa in length, while that of zebrafish (Danio rer/o) and rohu (Labeo rohita) is 171 aa in length. North-ern blot analysis revealed that SmTCTP has only one type of mRNA. Its expression level in albino skin was slightly higher than that in normal skin. We constructed the pET3Oa-SmTCTP expression plasmid. The recombinant protein of His-tag SmTCTP was over-expressed in E. coli, purified and identified with peptide mass fingerprinting. These results may pave the way of further inves-tigation of the biological function of TCTP in fish.     

Cloning and Analysis of Calmodulin Gene from Porphyra yezoensis Ueda （Bangiales, Rhodophyta）

In order to understand the mechanisms of signal transduction and anti-desiccation mechanisms of Porphyra yezoensis, cDNA and its genomic sequence of Calmodulin gene (CaM) was cloned by the technique of polymerase chain reaction (PCR) based on the analysis of P. yezoensis ESTs from dbEST database. The result shows that the full-length cDNA of CaM consists of 603 bps including an ORF encoding for 151 amino acids and a terminate codon UGA, while the length of genomic sequence is 1231 bps including 2 exons and 1 intron. The average GC content of the coding region is 58.77%, while the GC content of the third position of this gene is as high as 82.23%. Four Ca²⁺ binding sites (EF-hand) are found in this gene. The predicted molecular mass of the deduced peptide is 16688.72 Da and the pI is 4.222. By aligning with known CaM genes, the similarity of CaM gene sequence with homologous genes in Chlamydomonas incerta and Chlamydomonas reinhardtii is 72.7% and 72.2% respectively, and the similarity of the deduced amino acid sequence of CaM gene with homologous genes in C. incerta and C. reinhardtii are both 71.5%. This is the first report on CaM from a species of Rhodophyta.     

In Silico Screening for Microsatellite Markers from Expressed Sequence Tags of Porphyra yezoensis （Bangiales,Rhodophyta）

The genomic resources of Porphyra yezoensis expressed sequence tags （ESTs） were utilized to identify simple sequence repeats （SSRs）, or microsatellites. This method took the advantage of using ESTs and microsatellites either for the establishment of gene identities or for the acquisition of high polymorphism. The microsatellites can be used as gene markers when microsatellites are tagged to genes. Revealed by bioinformatics analysis, 1162 out of 21954 ESTs contained microsatellites and cluster analysis indicated that 984 of these ESTs fell into 112 contigs, while the other 178 ESTs were singletons. A total of 290 unique SSR-containing genes were identified. The AAC SSRs were the most populous type of microsatellites. GC-rich microsatellites were predominant among all the microsatellites.     

Structure of mitochondrial DNA control region of Pholis fangi and its phylogenetic implication

In this study, the entire mitochondrial DNA （mtDNA） control region （CR） of Pholis fangi was amplified via polymerase chain reaction followed by direct sequencing. The length of the mtDNA CR consensus sequence of P. fangi was 853 bp in length. In accordance with the recognition sites as were previously reported in fish species, the mtDNA CR sequence of P. fangi can be divided into 3 domains, i.e., the extended terminal associated sequence （ETAS）, the central conserved sequence block （CSB）, and the CSB domain. In addition, the following structures were identified in the mtDNA CR sequence of P. fangi：2 ETASs in the ETAS domain （TAS and cTAS）, 6 CSBs in the central CSB domain （CSB-F to CSB-A）, and 3 CSBs in the CSB domain （CSB-1 to CSB-3）. These demonstrated that the structure of the mtDNA CR of P. fangi was substantially different from those of most other fish species. The mtDNA CR sequence of P. fangi contained one conserved region from 656 bp to 815 bp. Similar to most other fish species, P. fangi has no tandem repeat sequences in its mtDNA CR sequence. Phylogenetic analysis based on the complete mtDNA CR sequences showed that there were no genetic differences within P. fangi populations of the same geographical origin and between P. fangi populations of different geographical origins.     

Characterization of genic microsatellite markers derived from expressed sequence tags in Pacific abalone (Haliotis discus hannai)

Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai).Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every 10.04 kb of EST sequences,after redundancy elimination.Seventeen polymorphic EST-SSRs were developed.The number of alleles per locus varied from 2-17,with an average of 6.8 alleles per locus.The expected and observed heterozygosities ranged from 0.159 to 0.928 and from 0.132 to 0.922,respective...     

Descriptions of three new species of Mitridae （Mollusca： Gastropoda） from South China Sea

Three new species of Family Mitridae （Mollusca： Gastropoda） from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI ＆ S. ZHANG, Neocancilla daidaleosa sp.nov. B. LI ＆ X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.     

Evaluation of three harvest control rules for Bigeye Tuna (Thunnus obesus) fisheries in the Indian Ocean

The stock of Bigeye tuna(Thunnus obesus) in the Indian Ocean supports an important international fishery and is considered to be fully exploited. The responsible management agency, the Indian Ocean Tuna Commission(IOTC), does not have an explicit management decision-making framework in place to prevent over-fishing. In this study, we evaluated three harvest control rules, i) constant fishing mortality(CF), from 0.2 to 0.6, ii) constant catch(CC), from 60000 to 140000 t, and iii) constant escapement(CE), from 0.3 to 0.7. The population dynamics simulated by the operating model was based on the most recent stock assessment using Stock Synthesis version Ⅲ(SS3). Three simulation scenarios(low, medium and high productivity) were designed to cover possible uncertainty in the stock assessment and biological parameters. Performances of three harvest control rules were compared on the basis of three management objectives(over 3, 10 and 25 years): i) the probability of maintaining spawning stock biomass above a level that can sustain maximum sustainable yield(MSY) on average, ii) the probability of achieving average catches between 0.8 MSY and 1.0 MSY, and iii) inter-annual variability in catches. The constant escapement strategy(CE=0.5), constant fishing mortality strategy(F=0.4) and constant catch(CC=80000) were the most rational among the respective management scenarios. It is concluded that the short-term annual catch is suggested at 80000 t, and the potential total allowable catch for a stable yield could be set at 120000 t once the stock had recovered successfully. All the strategies considered in this study to achieve a ‘tolerable' balance between resource conservation and utilization have been based around the management objectives of the IOTC.