Stage and tissue specific differences in SjBMI1, a Polycomb protein in Schistosoma japonicum

A method for the establishment of a cell line with stable expression of the GFP-LC3 reporter protein

As the function of autophagy becomes evident in a number of diseases, including cancer and infection, it is crucial to construct macrophage cell lines with stable expression of the microtubule-associated protein light chain 3 (GFP-LC3). In this study, a mouse LC3 open-reading frame was amplified by RT-PCR, and cloned into the pEGFP-C1 plasmid for expression of the GFP-LC3 fusion protein. The recombinant plasmid was transfected into RAW264.7 cells using Lipofectamine 2000 reagent and stably transfected clones were selected by G418 screening. Autophagic puncta formation was observed by fluorescense microscopy. Additionally, we found that starvation treatment induced a significant increase in the number of autophagosomes, while wortmannin treatment significantly repressed the formation of autophagosomes. This study indicated that the RAW264.7 cell line stably expressing GFP-LC3 is available for use in a GFP-LC3 puncta formation assay, and may contribute to basic investigations of autophagic function or drug screening targeted at autophagy.

Genome-wide identification and characterization of a panel of house-keeping genes in Schistosoma japonicum

Quantitative real-time polymerase chain reaction (qPCR), as one of the most sensitive and precise gene expression analysis methods, is frequently used to validate data obtained in high-through-put assays. qPCR requires reference genes with stable transcription for accurate normalization. However, no systematic studies on such genes have been performed in the genus Schistosoma japonicum. In this study, eight novel candidate genes selected from a microarray analysis and four commonly used reference genes were systematically validated in a series of qPCR experiments. Based on the results of geNorm, Normfinder, BestKeeper, and the comparative delta-cycle threshold (ΔCT) integrated analysis, the genes PSMD4, NDUFV2, and TPC2L were found to be most stably expressed in all S. japonicum developmental stages; meanwhile, ACTB and TUBA were found as the least stably expressed genes. This study provided, at the first time, data for genes that can be explored as reliable references in transcriptomic analysis of S. japonicum.