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Studying the function and mechanism of immune-related genes can provide scientific reference for preventing and controlling diseases in sea cucumber (A. japonicus) culture. In this study, the full-length cDNA of catalase gene from A. japonicus was cloned and characterized for the first time, which was 1 885 bp including a 76 bp 5'-untranslated region (UTR), 1 503 bp ORF encoding 500 amino acids, and a 306 bp 3'-UTR; and the predicted molecular weight was 56.56 kDa. The result of amino acid sequence alignment showed that 75% amino acid sequence identity to the Catalase of Hyriopsis cumingii and Strongylocentrotus purpuratus. The peroxisomal targeting signal PTS2, NADPH binding residues, and heme-ligand binding signal sequences "RLFSYPDTH" were identified in the deduced amino acid sequence of Catalase from A. japonicus. Phylogenetic analysis suggested that the Catalase of A. japonicus was close to that of S. purpuratus in invertebrate cluster. Quantitative real-time PCR analysis showed that catalase gene was expressed in all the tested tissues including body wall, feet, coelomocyte, respiratory tree, muscle, intestine, and the highest expression level was found in intestine. The expression of catalase mRNA was up-regulated significant!)' in the coelomocytes at 4 h after LPS challenge. Those indicated that catalase gene was involved in the immune response to the bacteria challenge in A. japonicus. [ABSTRACT FROM AUTHOR]

The presence of vector backbone sequences and selectable marker genes in transgenic plants has been the key concern for biosafety. A direct solution is to totally avoid the use of vector backbone sequences and selectable marker genes from the beginning of transgenic plant generation. In this study, the ovary-drip method was established and optimized. The key features of this method focused on the complete removal of the whole styles, and the subsequent application of a DNA solution directly to the ovaries. A vector backbone-free and selectable marker-free linear GFP cassette (Ubi-GFP -nos) was transformed into maize via the ovary-drip method. PCR analysis showed that suitable maize variety was 9818 and optimal transformation time was 18-20 h after pollination, which produced the highest PCR positive frequency (3.01%). Southern blotting analysis showed that the transgenic plants had simple integration patterns (1-2 bands). GFP transcription was de-tected by RT-PCR analysis. Green fluorescence was observed in roots and immature embryos of transgenic plants by a fluorescence microscopy.