Doublesex and mab-3 related transcription factor (dmrt) play crucial roles in sex determination and sex differentiation in vertebrates and invertebrates. Although dmrt genes have been identified in vertebrates, little is known about aquatic invertebrates. In this study, two dmrt genes, namely, Dc_dmrt93B and Dc_dmrt99B, were identified from brackish water flea, Diaphanosoma celebensis. Transcriptional changes were observed in the dmrt genes when the flea was exposed to bisphenol (BP), an endocrine disruptor. Sequence and phylogenetic analyses showed that both dmrt genes contained two conserved domains, namely, DM and DMA, closely clustered with those of Daphnia spp. Additionally, a significant increase in the Dc_dmrt99B mRNA expression level was observed upon exposure to intermediate concentrations of BP (bisphenol A>bisphenol S=bisphenol F, p<0.05), while the expression of Dc_dmrt93B mRNA was slightly modulated. These findings imply that the two dmrt genes may be involved in sex differentiation of D. celebensis. Furthermore, it was found that the ability of BP to modulate dmrt genes could affect development and reproduction. This study provides a basis for understanding the function of the dmrt genes and the molecular mode of action of BP in small crustaceans.
For people who have a food allergy the only way to manage the allergy is to avoid the food allergen. The mackerel is one of the major food allergens, but no immunoassay for the rapid and simple detection of mackerel has been reported. The objectives of this study are to develop and characterize monoclonal antibodies (MAbs) specific to mackerel using thermal stable-soluble proteins (TSSP) as an immunogen and to characterize the MAbs by indirect enzyme-linked immunosorbent assay (iELISA). The mice immunized with mackerel TSSP and showing high titer were used for cell fusion and cloning. The characterization of MAbs produced from hybridoma cells obtained was confirmed by indirect ELISA and western blot. Four MAbs were confirmed to be specific to mackerel without crossreaction to other marine products and livestock products in the both methods. The iELISA and western blot based on the MAbs can sensitively detect 1% mackerel protein in other marine products. These results support that immunochemical methods based on the MAb produced could be used as rapid means to detect low levels of mackerel and to identify mackerel adulterated in food.
Colorectal cancer is the third most commonly diagnosed cancer in the world, nearly all patients diagnosed with this cancer die from it. Antibodies are glycoprotein molecules, which can efficiently recognize and eliminate specific pathogenic and disease antigens. Antibody researches for the last several decades have demonstrated the potential of therapeutic antibodies to fight cancer. Monoclonal antibody (mAb) CO17-1A recognizes the tumor-associated antigen GA733-2, a cell surface glycoprotein highly expressed in colorectal carcinoma cell, which is applicable for preventing and curing colorectal cancer. We have currently established baculovirus insect cell expression system to produce anti-colorectal cancer mAb CO17-1A. In this study, mAb CO17-1A was expressed in the transgenic insect cell line SWT4, which has humanized glycosylation processing pathway. Immunoblot confirmed that mAb CO17-1A properly expressed in SWT4. mAb CO17-1A was purified using protein G affinity column. In addition, Maldi-TOF verified that the mAb fused to KDEL, ER retention signal had high mannose type of glycan structure whereas the mAb without KDEL had partially humanized glycan structure. These results suggest that the insect cell expression system with the SWT4 possibly can be used as a useful alternative way to produce full-size mAb with humanized glycan structures for cancer immunotherapy.
The goal of marker-assisted backcrossing is to reduce the number of generations significantly by using genome-based molecular markers. Among other types of molecular markers, SNP (single nucleotide polymorphism) is mostly used in genetic diversity analysis due to its abundance. To develop high-throughput SNP marker for MAB system, we selected 20 Chinese cabbage lines each represent traits as inner leaf color, disease resistance, head type and maturity etc. Then, we sequenced the transcriptomes of 20 lines by using Illumina Hiseq2000. The average transcriptome size was 1.37 Gbase, and the average of short reads mapping rate was about 62.15% (30xcoverage). We identified 13,976 SSR markers and 380,198 SNPs by aligning contigs of 20 Chinese cabbage lines. To develop SNP marker set, we chose 409 SNPs that covers the whole Brassica rapa transcriptome. The filtering criteria were depth, polymorphism, segregation ratio, lack of adjacent SNP and copy number. We positioned the selected SNP markers to the Chinese cabbage linkage map. Clustering dendrogram was produced using SNP marker and three different clusters were generated. The result showed that the genotyping data is partially linked to the phenotyping data. We assume that the developed SNP marker set can be applied in the Chinese cabbage MAB system soon.