Differential gene expression in the body wall of the sea cucumber(Apostichopus japonicus)under strong lighting and dark conditions

Sea cucumber, Apostichopus japonicus is very sensitive to light changes. It is important to study the influence of light on the molecular response of A. japonicus. In this study, RNA-seq provided a general overview of the gene expression profiles of the body walls of A. japonicus exposed to strong light（＂light＂）, normal light（＂control＂） and fully dark（＂dark＂） environment. In the comparisons of ＂control＂ vs. ＂dark＂, ＂control＂ vs. ＂light＂ and ＂dark＂ vs.＂light＂, 1 161, 113 and 1 705 differentially expressed genes（DEGs） were identified following the criteria of｜log2 ratio｜≥1 and FDR≤0.001, respectively. Gene ontology analysis showed that ＂cellular process＂ and ＂binding＂enriched the most DEGs in the category of ＂biological process＂ and ＂molecular function＂, while ＂cell＂ and ＂cell part＂ enriched the most DEGs in the category of ＂cellular component＂. And the DEGs were mapped to 214, 41 and229 pathways in the Kyoto Encyclopedia of Genes and Genomes database, and 51, 2 and 57 pathways were significantly enriched, respectively. Light-specific DEGs identified in this study will be important targets for further investigation to establish the biochemical mechanisms involved in the adaption of this sea cucumber to changes in the level of environmental light.

Matrix attachment regions included in a bicistronic vector enhances and stabilizes follistatin gene expressions in both transgenic cells and transgenic mice

In the present study, follistatin(FST) gene expression vectors with either a bicistronic gene transfer cassette alone, or a bicistron gene cassette carrying a matrix attachment region(MAR) were constructed and transfected to bovine fetal fibroblasts. Evaluations of both the integration and expression of exogenous FST indicated that the p MAR-CAG-FST-IRES-Ac GFP1-poly A-MAR(pMAR-FST) vector had higher capacity to form monoclonal transgenic cells than the vector without MAR,though transient transfection and integration efficiency were similar with either construct. Remarkably, protein expression in transgenic cells with the p MAR-FST vector was significantly higher than that from the bicistronic vector. Exogenous FST was expressed in all of the p MARFST transgenic mice at F_0, F_1 and F_2. Total muscle growth in F_0 mice was significantly greater than in wild-type mice,with larger muscles in fore and hind limbs of transgenic mice. p MAR-FST transgenic mice were also found with more evenly distributed muscle bundles and thinner spaces between sarcolemma, which suggests a correlation between transgene expression-associated muscle development and the trend of muscle growth. In conclusion, a p MAR-FST vector, which excluded the resistant genes and frame structure, enhances and stabilizes FST gene expressions in both transfected cells and transgenic mice.

Specifications of Targeting Heterochromatin Modifications in Plants

Plants encode a diverse repertoire of DNA methyltransferases that have specialized to target cytosines for methylation in specific sequence contexts. These include the de novo methyltransferase, DOMAINS REARRANGED METHYLTRANSFERASE 2 （DRM2）, which methylates cytosines in all sequence contexts through an RNA-guided process, the CHROMOMETHYLASES （CMTs）, which methylate CHH and CHG cytosines （where H is A, T, or C）, and METHYLTRANSFERASE 1 （MET1）, which maintains methylation of symmetrical CG contexts. In this review, we discuss the sequence specificities and targeting of each of these pathways. In particular, we highlight recent studies that indicate CMTs preferentially target CWG or CWA/CAW motifs （where W is A or T）, and discuss how self-reinforcing feedback loops between DNA methyltransferases and histone modifications characteristic of heterochromatin specify targeting. Finally, the initiating events that lead to gene body methylation are discussed as a model illustrating how interde- pendent targeting of different silencing pathways can potentiate the establishment of off-target epialleles.