ABSTRACT
BACKGROUND:Poultry mesenchymal stem cels are a particular subset of pluripotent adult stem cels derived from the mesoderm, which have great application prospects because of their strong proliferation and multi-directional differentiation potential. OBJECTIVE:To review the source, separation, purification, culture and differentiation of poultry mesenchymal stem cels, and to provide the theoretical foundation and experimental basis for the further research and application of poultry mesenchymal stem cels. METHODS:PubMed and CNKI databases were searched by the first author using key words of “mesenchymal stem cels, poultry, chicken, isolation, culture, differentiation” in English and in Chinese, respectively, to retrieve relevant articles published from 1990 to 2014. Literatures addressing induced poultry mesenchymal stem cels were included, and 42 articles were chosen for further analysis eventualy. RESULTS AND CONCLUSION: Poultry mesenchymal stem cels have great application prospects in the aspects of establishingin vitro model of poultry cels, studying poultry disease pathogenesis, animal nutrition and meat quality control. Its origin source is wide and easy to obtain. Isolation, purification, culture and biological characteristics of mesenchymal stem cels from different tissues are different. But, the study on poultry mesenchymal stem cels is stil in the exploration process, and there are many technical problems to be solved.
ABSTRACT
In the present study,we examined the codon usage bias between pseudorabies virus (PRV) US1 gene and the US1-like genes of 20 reference alphaherpesviruses.Comparative analysis showed noticeable disparities of the synonymous codon usage bias in the 21 alphaherpesviruses,indicated by codon adaptation index,effective number of codons (ENc) and GC3s value.The codon usage pattern of PRV US1 gene was phylogenetically conserved and similar to that of the US1-like genes of the genus Varicellovirus of alphaherpesvirus,with a strong bias towards the codons with C and G at the third codon position.Cluster analysis of codon usage pattern of PRV US1 gene with its reference alphaherpesviruses demonstrated that the codon usage bias of US1-like genes of 21 alphaherpesviruses had a very close relation with their gene functions.ENc-plot revealed that the genetic heterogeneity in PRV US1 gene and the 20 reference alphaherpesviruses was constrained by G+C content,as well as the gene length.In addition,comparison of codon preferences in the US1 gene of PRV with those of E.coli,yeast and human revealed that there were 50 codons showing distinct usage differences between PRV and yeast,49 between PRV and human,but 48 between PRV and E.coli.Although there were slightly fewer differences in codon usages between E.coli and PRV,the difference is unlikely to be statistically significant,and experimental studies are necessary to establish the most suitable expression system for PRV US1.In conclusion,these results may improve our understanding of the evolution,pathogenesis and functional studies of PRV,as well as contributing to the area of herpesvirus research or even studies with other viruses.