ABSTRACT
@#The CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated) system is an "adaptive immune system" found in the genomes of bacteria and archaea which is mediated by RNA and resists foreign nucleic acid invasion.Take advantage of specific recognition of target nucleic acid, CRISPR-Cas system can efficiently edit their target site or accurately regulate gene expression, and now have been developed into a powerful tool for gene editing.According to the different compositions of the effector complex, the system has been divided into two categories: class 1 (type I, type IV, and type III) and class 2 (type II, type V, and type VI).Class 2 system, like the CRISPR-Cas9, is widely used in basic research due to the earliest discovery and best research.However, class 1 has not been maturely developed and utilized though it makes up 90% of the entire CRISPR-Cas system.In this essay, the classification of subtype, the assembly of Cascade complex, the cleavage and degradation mechanism of Cas3, and the application in gene editing of class 1 type I CRISPR-Cas system will be discussed and summarized to provide new ideas and methods for further mechanism studying and application of this category.
ABSTRACT
Inflammasome is the body of protein complex which is able to identify different stimulation signals and can in‐duce immune and inflammatory responses when it is activated .NLRP3 inflammasome has been extensively studied in the central nervous system .Microglia ,perivascular macrophages and meningeal macrophages express inflammasomes .The occurrence and development of acute brain infection ,aseptic acute brain injury ,Parkinson disease and Alzheimer disease are closely related to inflammasomes .Based on mechanisms exploration of the inflammasome′s role in the central nervous system disorders ,its tar‐get drug research and development will be greatly addressed in the future .
ABSTRACT
Objective To investigate the effects of down-regulation of Beclin 1, which is an autophagy regulatory molecule, expression induced by RNA interference on the proliferation and apoptosis in skin fibroblasts of naked mole rat. Methods The expression levels of Beclin 1 were detected after starvation or H2 O2 treatment.The fibroblasts were transi-ently transfected with specific siRNA targeting Beclin 1 and then screened by real-time PCR and Western blot.Cell prolifer-ation and apoptosis were determined using CCK-8 detection kit and flow cytometry ( FCM ) .The expressions of related genes were detected by Western blot.Results The expression of Beclin 1 gene at mRNA and protein levels was signifi-cantly lower in fibroblasts of the naked mole rat.Starvation and H2 O2 treatment induced changes of the Beclin 1 expression. Inhibition of Beclin 1 gene expression can inhibit cell proliferation and induce early and late apoptosis.The protein levels of p53, BAX, Bcl2, LC3B, p-AKT and mTOR were reduced after transient transfection with Beclin 1-siRNA.Conclusions The expression of Beclin 1 in fibroblasts of naked mole rat are changed in response to starvation or H2 O2 stimulation.Inhi-bition of Beclin 1 gene expression can inhibit cell proliferation and induce apoptosis.Therefore, Beclin1 gene may play a regulatory role in autophagy, proliferation and apoptosis in the skin fibroblasts of naked mole rat.
ABSTRACT
According to the principles of constructing evaluation index system in designed experiments,we formulated the content,designed the weights and established the evaluation index system in designed experiments based on analytical hierarchy process and Delphi.This system can assess students' cognition and attitudes,abilities of innovation,practice,teamwork and cooperation as well as scientific writing skills by providing objective and comprehensive evaluation criteria.
ABSTRACT
This paper discusses application of multimedia and network technology in Laboratory Animal Science Teaching:We have set up multimedia courseware,made animal experiment video and built network course-learning system and a good teaching effect has been achieved.Then it analyzes the problems of multimedia and network technology in Laboratory Animal Science Teaching.