Morphological and molecular characterization of Paraleptus chiloscyllii Yin & Zhang, 1983 (Nematoda: Physalopteridae) from the brownbanded bambooshark Chiloscyllium punctatum Müller & Henle (Elasmobranchii: Orectolobiformes).

Paraleptus (Spirurida: Physalopteridae) is a small genus of nematodes, parasitic in fishes, most species of which are inadequately described. Genetic data for these congeners have not been reported. The detailed morphology of P. chiloscyllii was studied using light and scanning electron microscopy, based on newly collected specimens from the brownbanded bambooshark C. punctatum Müller & Henle (Elasmobranchii: Orectolobiformes) in the Taiwan Strait. Some previously unreported morphological features of taxonomic significance were observed, i.e., pseudolabium with two sublateral rows of 6-7 small spines, 7-8 small spines on each lower rim between pseudolabia, deirids not distally bifurcated, vulva with remarkable protruding lip, presence of 1 pair medio-ventral precloacal papillae and 1 pair of discoid protrusions of postcloacal lip in male. The specimens described by González-Solís & Ali's (2015) as P. chiloscyllii from the Arabian carpetshark C. arabicum off Iraq are considered a new species, for which the name P. moraveci n. sp. is proposed. The genetic characterization of the partial small (18S) and large (28S) ribosomal DNA, and the partial mitochondrial cytochrome c oxidase subunit 1 (cox1) of P. chiloscyllii are provided for the first time. There was no intraspecific nucleotide divergence detected in the 18S and 28S regions among different individuals of P. chiloscyllii, but a low level of intraspecific genetic variation was found in the cox1 (0.62-0.92%). The present genetic data is very important for molecular identification, and will be valuable for further invertigantions on the population genetics and phylogeny of this group.

[Sited-directed mutagenesis of hCu, Zn-SOD gene and its expression in Synechococcus sp. PCC7942].

The Cys111 genetic code of human copper/zinc superoxide dismutase (hCu, Zn-SOD) gene in the pESOD plamid was mutated into the Ala111 code with site-directed mutagenesis, and then the plamid pESODT111 which contained groESL promoter, mutated hCu, Zn-SOD gene, rbcS-polyA terminator and reporter gene (Kanr) was constructed and transduced into Synechococcus sp. PCC7942 with homologous recombination platform. The results of PCR and DNA sequence analysis showed that the target nucleotide had been genetically integrated into genome DNA of the host cell. SDS-PAGE, Western blot and Pyrogallol autoxidation assay confirmed that the transformant strains expressed the mutated hCu, Zn-SOD protein. And the level of the mutated hCu, Zn-SOD protein reached a value of 3.61% of the total soluble protein. Furthermore, the transformants still retained 95% activities of SOD after 30 minutes at 80 degrees C environment, it indicated that the mutated hCu, Zn-SOD protein could endure higher temperature than the natural one.

[Construction of shuttle expression vector and expression of thymosin alpha 1 in Synechococcus sp. PCC7942].

The shutter expression vector pPREUT was constructed from the plasmid pPRS-1 containing the endogenous small plasmid of Plectonema boryanum. The expression elements such as heat shock gene groESL promoter, foreign gene Ub-thymosin alpha 1, rbcS polyA terminator and Kanamycin resistance gene were all included. The shutter plasmid pPREUT was directly transferred into Synechococcus sp. PCC7942. The transformants were obtained through Kanamycin screening. Southern blotting analysis showed that the shutter plasmid have been transferred into Synechococcus sp. PCC7942. After induction by heat shock(42 degrees C) for 30 min, the foreign protein UB-T alpha 1 was expressed efficiently, which reached 7.5% of total amount protein.

[Study on high efficiency tissue culture of mature seeds of rice (JiaHe-ZaoZhan)].

In order to improve the embryogenic callus induction rate and the regeneration rate of JiaHe-ZaoZhan rice, the influence of different factors were investigated, media with different hormones were used. Induction medium was supplemented with 1.5 mg/L 2,4-D + 3 mg/L NAA + 0.1 mg/L KT + 1 mg/L phytic acid + 20 mg/L PAA. Embryogenic call were treated under the condition of 25 degrees C before transferring to regeneration medium, the regeneration medium contained 0.5 mg/L 6-BA + 3 mg/L NAA + 0.5 mg/L KT + 1 mg/L phytic acid. The experiment results indicated that the hormone treatments had certain effects on the callus induction. Under the optimal medium, culture condition and the hormone treatments, the embryogenic callus induction could reach over 95%, and dry treatment of embryogenic callus had been found to increase the frequency of plant regeneration, significantly the plant regeneration rate could reach over 80%. Transplanted into pots, the young plants grew well. Then a experimental system with stability and high regenerating efficiency has been established for the mature seeds of rice (JiaHe-ZaoZhan).