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Silk fibroin (SF) is a protein-based biomacromolecule with excellent biocompatibility, biodegradability and low immunogenicity. The development of SF-based nanoparticles for drug delivery have received considerable attention due to high binding capacity for various drugs, controlled drug release properties and mild preparation conditions. By adjusting the particle size, the chemical structure and properties, the modified or recombinant SF-based nanoparticles can be designed to improve the therapeutic efficiency of drugs encapsulated into these nanoparticles. Therefore, they can be used to deliver small molecule drugs (e.g., anti-cancer drugs), protein and growth factor drugs, gene drugs, etc. This paper reviews recent progress on SF-based nanoparticles, including chemical structure, properties, and preparation methods. In addition, the applications of SF-based nanoparticles as carriers for therapeutic drugs are also reviewed.

Procambarus clarkii, commonly known as "crayfish" or "freshwater crayfish", is one of the most important freshwater aquaculture species in Chinese mainland. Recently, the aquaculture area and production of the crayfish in Chinese mainland have been continuously increased. However, the stress response caused by various factors, such as climate change, transportation and environmental change has led to more and more serious problems, including explosive disease and even death during culturing the crayfish, which not only decreased the crayfish product quality, but also resulted in serious damage to the crayfish breeding industry. In this study, we first treated the crayfish by transportation and temperature stresses to select the stronger stress resistant (SSR) and the weaker stress resistant (WSR) crayfishes. Then we dissected the hepatopancreas of SSR and WSR crayfishes to compare the metabolomics by Liquid Chromotography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS). A total of 10292 ions were detected, from which 464 metabolites were identified to be significant different between SSR and WSR (fold change>1.2, P<0.05, and VIP>1.0). Among them, 227 metabolites were down-regulated and 237 metabolites were up-regulated in SSR relative to WSR. KEGG analysis showed that these differential metabolites were mainly enriched in amino acid metabolic pathways, including histidine metabolism, taurine and hypotaurine metabolism, lysine degradation, valine, leucine and isoleucine biosynthesis, and glutathione metabolism. They also enriched in ascorbate and aldarate metabolism, carbohydrate metabolic pathways (pentose and glucuronate interconversions), fatty acid metabolic pathways (unsaturated fatty acid biosynthesis), etc. These results indicate that there are a wide range of metabolic responses in response to transportation and temperature stress, and some metabolites related to antioxidative stress and enhancing immunity, such as γ-L-Glutamyl-L-cysteine, taurine, and oleic acid, may play an important role in the stress resistance in P. clarkii. This study can not only provide new insights for studying mechanisms of animal stress resistance, but also have important value in developing strategies to cope with the stress response and in breeding new aquaculture strains with strong stress resistance. [ABSTRACT FROM AUTHOR]

The family Chironomidae is represented by seven subfamilies in China, among which Chironominae and Orthocladiinae are the most diverse. To gain a better understanding of the architecture and evolution of the mitogenomes of Chironomidae, we sequenced mitogenomes of twelve species (including two published species) of the two subfamilies Chironominae and Orthocladiinae, and comparative mitogenomic analyses were performed. Thus, we identified highly conserved genome organization of twelve species with regard to genome content, nucleotide and amino acid composition, codon usage, and gene characteristics. The Ka/Ks values of most protein-coding genes were far smaller than 1, indicating that these genes were evolving under purifying selection. Phylogenetic relationships between the family Chironomidae were reconstructed using 23 species representing six subfamilies, based on protein-coding genes and rRNAs using Bayesian Inference and Maximum Likelihood. Our results suggested the following relationship within the Chironomidae: (Podonominae + Tanypodinae) + (Diamesinae + (Prodiamesinae + (Orthocladiinae + Chironominae))). This study contributes to the mitogenomic database of Chironomidae, which will be significant for studing the mitogenome evolution of Chironomidae. [ABSTRACT FROM AUTHOR]

ABSTRACT Background: Alternative splicing (AS), which plays an important role in gene expression and functional regulation, has been analyzed on genome-scale by various bioinformatic approaches based on RNA-seq data. Compared with the huge number of studies on mouse, the AS researches approaching the rat, whose genome is intermedia between mouse and human, were still limited. To enrich the knowledge on AS events in rodents' brain, we perfomed a comprehensive analysis on four transcriptome libraries (mouse cerebrum, mouse cerebellum, rat cerebrum, and rat cerebellum), recruiting high-throughput sequencing technology. An optimized exon-exon junction library approach was introduced to adapt the longer RNA-seq reads and to improve mapping efficiency. Results: In total, 7,106 mouse genes and 2,734 rat genes were differentially expressed between cerebrum and cerebellum, while 7,125 mouse genes and 1,795 rat genes exhibited varieties on transcript variant level. Only half of the differentially expressed exon-exon junctions could be reflected at gene expression level. Functional cluster analysis showed that 32 pathways in mouse and 9 pathways in rat were significantly enriched, and 6 of them were in both. Interestingly, some differentially expressed transcript variants did not show difference on gene expression level, such as PLCβ1 and Kcnma1. Conclusion: Our work provided a case study of a novel exon-exon junction strategy to analyze the expression of genes and isoforms, helping us understand which transcript contributes to the overall expression and further functional change.